Author Topic: My version of Bogstandard's Paddleducks engine build log  (Read 15589 times)

Offline spuddevans

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My version of Bogstandard's Paddleducks engine build log
« on: July 20, 2012, 09:56:03 PM »
I just thought I would post up a copy of the build log of Bog's famous Paddleducks marine engine. The plans are available at a couple of places including Here

I hope that this is in the right section, if not please accept my apologies. I also apologise for the sheer size of this log, it turned out a real epic tome.

Part 1.

I have finally got round to making a start on my next project, and while tempted to do a Rocking engine, I had to stick with with my initial plan of building

Bog's Paddleducks engine.

So I had previously got some materials gathered for this build, and not having any cast iron at all, but having a brass block that was itching to be reduced

to a nice cylinder-shaped block, I decided to use brass for the cylinder.

Here is the raw brass block, the other dimensions are 25mm thick and 50mm high.

I then used my very expensive marking dye system and used my vernier caliper to mark out a rough shape to then transfer to my very expensive bandsaw

(my right arm)

So I next ground up a tiny toolsteel for my tiny flycutter as per the Bogstandard curved profile that I read about. This is my second attempt at grinding the

curved shaped flycutter, I have a larger flycutter that doesnt cut as well as this latest attempt, practice I guess  ::)

So with this newly ground up tool I am totally impressed with it. The finish on brass is soo silky smooth!!! Compare it to using a end-mill and there is just no

contest. I also learnt that my X2's Z axis is made out of a very tough but flexible form of spagetti. I am intending on re-inforcing the upright column, but in

the meantime I have to be mindful of taking lighter cuts.

I have an even smaller flycutter, they're so dinky.

So after squaring and sizing the 4 sides I then squared off the 2 ends with a 4-flute mill.

It's amazing how the little brass chippings/shavings get everywhere (especially down the neck of my teeshirt, and they are pretty hot too) My workbench

was (and still is) covered with a golden snowstorm.

I then had to smooth the 2 ends with some 360grit wet+dry placed on a granite plate to try and get them to match the smooth flycutter-ed surfaces.

And here it is, the first part made to size (well within 0.02mm on 2 dimensions and dead on the 3rd )

 If you want to see larger versions of the pictures of this build click here

I got some time in the workshop today, and started out by Tramming my mill. A frustrating exercise as when you think it is in tram and then tighten the big

nut holding the column in place, the act of tightening will throw the mill out of tram again. 

After tramming the mill I started marking up the main block for the cylinder holes, then clamped the block in the vice on top of some 1/2" parallels. I then

used the edge finder to locate the hole centres as accurately as possible, and then centre drilled them. Working out the graduations on the mills

handwheels it worked out at 18 full turns to traverse from the center of one hole to the center of the other.

I then drilled and then opened out the holes starting with a 4mm drill, then 6mm, 7mm, 8mm, 8.5mm 8.7mm, 8.8mm, 8.9mm and then finally reamed the

bores to 9mm. ( I would have drilled/reamed them 10mm but I dont have a 10mm reamer, but I do have a 9mm reamer so I figured that making the bores

slightly smaller would not make a big difference. I'll just make the pistons to match )

And this is the end result.

I then turned (groan) to making the Top-Caps. I chucked up a length of some unknown steel ( to contrast with the brass ) in my 4jaw ( my 3jaw

self-centering has too small a bore to allow the length to go into the headstock in order to use it without cutting it down ) Turned a section down to 18mm

diameter, put a 9mm spigot on to fit the bore, then parted it off, and then repeated for the other.

Then I mounted my ER32 chuck, the 18mm collet and mounted the topcap in it to turn the "Top" side. The 2nd one turned out better, practice makes

perfect better.

Here's what they look like mounted on the block.

Then I started on the packing nuts, I chucked up some 8mm hex brass bar, turned a 6mm section and then threaded it.

Then we parted it off and did the same again.

The only thing that bothers me a bit about these is that, because of the width of my parting tool there isnt much thread left, about 2.5-3 turns on each nut.

Then we cut off some 22mm round brass bar for the packing gland, chucked it up and turned down to 18mm.  Then we turned down an 8mm section and

put a center drill in the chuck and almost drilled it.

I then started off by grinding up a new undercutting tool, about 0.8mm wide, here shown with one of the previously made gland adjustment screws for


Then I chucked up the brass hex bar in the 3jaw and turned down a little section for threading using a 6mm round profiling tool.

Then I used the new undercutting tool to, umm, ........ undercut a groove

and then single point threaded a M6 thread

And within a short time I had a little family made up.

After changing over to the ER32 collet chuck that still had the packing gland mounted in it. I centre drilled, drilled and then tapped M6 to 5mm depth as per

the plans. ( I had to grind down the tips of the taps as they were quite long and tapered to a point, too long to use in this application)

Then I mounted one of the gland screws and screwed it well in, then tidied up the backside of the screw, and then drilled the two pieces at once to keep

concentricity, I drilled them 2.2mm then 2.9mm and finally 3mm.

Then I removed the adjusting screw, then reversed the packing gland and turned down the reverse side to fit the bore. This is the result.

Here is what it looks like in its place.

So I got a little more done today. I started by making the 2nd packing gland. I didnt take any pics of this, but here's one of the 2 packing glands in place.

I then made a start on the piston assembly, starting by roughing the pistons to within 1mm of final size, drilled and then tapped M2.5 and then bored

2.5mm 1mm deep to allow the rod to seat properly.

then parted off approx 6mm and repeated to make the other piston.

I then started on the rods, and following on from the single point threading thread I was determined to single point it. However, the chart of gears for my

lathe did not list 0.45mm pitch as an option. After some not inconsiderable head scratching and vain calculations I gave up and came indoors to download

Mklotz's "Change" program, entered my leadscrew pitch and the change gears that I have and it gave me a solution.

Back out to the workshop and a few mins later I was ready to cut. 1st off I centre drilled the end of the rod and brought up the tailstock with my new

ball-raced center. Then it was just a case of making a few passes to get to near depth.

Then I removed the tailstock and finished the thread form off with a Die.

Then did it again for the other piston. Then I assembled the bits with some loctite and set them aside to set.
« Last Edit: July 22, 2012, 07:41:08 AM by spuddevans »
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #1 on: July 20, 2012, 09:56:32 PM »
Part 2.

Well having the day off today I was able to steal a few hours in the playroom workshop.

I started off with the pistons, I chucked one up in the ER32 collet.

I then turned it to 6mm length, turned the diameter to just be able to fit into the bore, then installed an oil groove. Then I used some 600grit and then

1000grit wet+dry to polish the piston to be a nice snug fit in the bore. ( I also eased the sharp edges off with the same 600grit )

I did the same to the other piston, this one was ever-so-slightly smaller ( to match the ever-so-slightly smaller bore ), and so I marked both the pistons and

the bores so that I can match them up again, I used a couple of pop-marks on each part.

I then turned my attention to the crossheads, and after hacksawing some brass to make some smaller brass, I started to clean up and square up the pieces,

and then to finally size them.

Here they are marked up and ready for drilling.

I didnt want to just rely on the markings, so I used my edge finder and then used the dials to get to the right position. I then drilled one hole before using

the dials to get to the next position. This might seem overkill, but one of the blocks of brass was just slightly smaller than the plans called for, so I marked

a datum face on both crossheads and indicated off this datum to get to the hole positions. This would make sure that the holes will be in exactly the right

places relative to each other ( if not relative to the sides of the block )

I then drilled the hole in the side of the blocks

Here are the 2 crossheads drilled and ready to mill. Can anyone spot the (almost catastrophic) Boo-Boo?

On the second block ( cunningly labeled "2" in the pic ) I drilled the 2.5mm hole correctly, I then moved over, using the dials, to the correct place on the

X-axis, and misread, or miscalculated, my dial position on the Y-axis and drilled the 4mm hole 0.5mm too close to the edge ( the centre was 3.5mm in from

the edge instead of the 4mm called for in the plans. )

Instantly thoughts of how I was going to rectify this sprang into mind, the 1st one being to silver solder a 4mm brass rod into the hole and then to re-bore in

the right place. But after I thought for a while it occurred to me that if I make the other 4mm hole out by the same error I can just position the crosshead

rods to match. Hence the numbering of the crossheads.

I started on shaping the crossheads. I used a plunge-cutting-rounding-over mini-router bit from my dremel-clone to shape it.

Then after centering it I cut it down both sides and the middle.

Then the other one, and then I marked them both up for milling.

Mounted in the vice on some parallels and cut down both sides of the fork.

Then I milled out the centre of the fork, opened out one hole from 3mm to 4mm, and then rounded off some edges and then spent a fair bit of time in

smoothing out with 360, 600, and then 1000 grit wet-n-dry, and then re-reamed the deep 4mm holes for the crosshead rods and tapped the M3 hole.

And here it is next to the unmilled crosshead block.

As you can see on the unmilled crosshead, I've drilled 2 6mm holes in order to get a nice curve profile between the upright guide portion and the fork part.

I had been toying with the idea of milling a couple of, say 2mm slots to expose part of the crosshead-rods, but I didnt have a 2mm or smaller cutter and I

wasnt sure if it would negatively effect the crossheads themselves.

That's all that I was able to get done today, the shaping took a little longer than I thought, but I didnt want to rush at it as it would be a real bummer to

mess up on one of these crossheads. I'll work on the 2nd crosshead over the weekend.


This afternoon I got started on the 2nd crosshead. It is amazing how much quicker you can make a part when you know what you are doing ( well I sort of

know what I'm doing  :lol: ) This one went quickly and I managed to get a bit better finish of the tool on this one.

Here's the 2 finished crossheads.

Now, the observant of you may have noticed that when I made both the top-caps and the packing glands, I didnt drill them for mounting holes. Well after I

finished the crossheads, and feeling a little left out of the whole "I-made-a-jig-to-drill-these-parts" party, I made a jig to help drill these parts.  :D

The idea is to drill one hole through the relevent top plate or packing gland, insert brass pin into newly drilled hole and release vice and rotate 90degrees,

retighten the vice, drill again, and then from then on just take out the pin, rotate the topcap 90 degrees insert pin again and drill.

The jig made it very quick to drill the holes in alignment. The jig didnt take long to make, the centering of the square block of ali' in the 4jaw took the


So here is a pic of all the parts I've made so far.

As you can see, the topcaps are a little rough looking, so I may remake them at some later stage.

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #2 on: July 20, 2012, 09:57:02 PM »
Part 3.

Well I got just a little more done.

I marked up the main block for the steam ports, and realising that they are centrally aligned and are set in the same distance from the end I decided to use

my very high-tech vice stop to make drilling a lot easier. ( hey, I'm really getting into this whole "using jigs and stops to make machining easier" thing! ) 1st

up was center drilling the 4 ports, then drilling through to the cylinder bores.

Then, not yet having in my grubby little hands the 2mm brass sheet needed for the mounting plates, I skipped on a couple of steps in the plans to make

some of the little things. I made the 4 crosshead rods, well, when I say I made them I just cut some 4mm stainless rod to length and then drilled and

tapped one end.

Then I marked up the piston+rod assembly for cutting to length, chucked up a piston with the rod facing out of the ER32 collet and parted off to size, then

did the same to the other piston assembly. Then I single pointed a M3 thread on each piston rod and finished off the thread with a M3 die.

So here is a mockup of the crosshead rods in the crossheads, along with the threaded piston assemblies also mounted in the crossheads.

Well I made a little progress today (the emphasis being on "little")  I got some 2mm brass sheet and hacked off a section and then milled the 2 freshly cut

edges smooth and to size. I then blued ( well, blacked actually ) one surface with layout dye ( a big black marker from tescos ) and then spent a fair bit of

time marking out all the holes, remembering that I had to make an adjustment for one set of crosshead-rod-mounting-holes as I had drilled one crosshead

slightly incorrectly.

Just after taking that Pic I removed the piece from the vice and just made little centre punch marks ( more like "pop" marks actually ), then remounted it in

the vice and drilled all the small holes. For the 2 packing gland holes I drilled out as big as I had drills ( 13mm ) and then switched to my Boring bar setup.

While not ideal for this, it seemed to work ok, although a little slow. ( My boring bar is marked in imperial and I was working in metric, so progress was a

little slow as I approached final diameter as I didnt want to over-shoot if I could help it )

Here's the top-plate bored out, sitting on the main cylinder block and the packing glands sitting in place.

Next I have to drill and tap for the packing gland / top-cap mounting holes, and drill and tap for the mounting plate holes.

I started by milling out a recess on the mounting plate for the steam chests.

Then I drilled and tapped the cylinder block using a newly aquired tapping stand, I totally reccomend everyone either make or buy one, makes tapping so

much easier 

I only drilled and tapped the bottom of the block as I've decided to remake the top-caps as I messed up the holes on them.

I then did a little assembly. After a little polishing on one piston, ( on the rod not the actual piston, as the rod was slightly oversize ( about 0.04mm ) and

would not go through the packing gland ) I was able to assemble the pistons and packing glands into the cylinder, and then attach the mounting plate.

Then I assembled the crossheads and rods, and after a little fiddling and messing around, widening one set of crosshead-rod-holes a little, and ...... It

slides in and out !!! (ok a little stiff, but it still works)

Today I got started on remaking the topcaps, this time out of brass.

I started with a chunk of 22mm brass rod in the 3jaw to which I trued up the end and turned as much as could be reached down to 18mm.

I then mounted my ER32 chuck and reversed the brass rod into it and turned the rest of it down to 18mm. Then I turned down the top of the 1st topcap to

8mm appox.

I then extended the rod out a bit from the collet, and parted off leaving enough stock to be able to turn a spigot to fit the cylinder bore. Then I did the

exact same again for the 2nd topcap. Then I remounted the topcaps in a 8mm collet ( gripping the freshly turned 8mm top of the topcaps ) to turn the

spigot that would fit into the bore. I took off a fraction at a time, checking it against the cylinder bore, until it just fitted inside.

Then I got out my little jig mentioned earlier to drill the 4 holes in each of the topcaps. Then it was over to the cylinder block itself. Using the newly

(re)made topcaps I marked out the positions for the mounting holes, drilled them and then tapped them M2 using my tapping stand.

Then it was just a case of building all the parts back up again. Funnily enough, the crosshead/rod-assembly that took all the fiddling the 1st time I built it

up, took almost no fiddling this time to get moving. And wouldnt you know it, the one that went together easily last time, it took ages of fiddling and

enlarging of the rod mounting holes ( I hadnt enlarged this set of holes the 1st time ) 

But here is what the top looks like with the newly made topcaps.

Next it will be the bearing blocks. I am toying with the idea of using ball races in the bearing blocks, its only 4 ball races so the cost wouldnt be too bad.

I got started on making the bearing blocks. I took some square brass bar and chopped 4 pieces off it. I put the 4 bits in the vice on some parallels.

Now, I know that all 4 pieces came from the one bar, but I wanted to make sure that they each would be clamped tight so I put 4 little thin pieces of ali,

one inbetween the moving jaw and each block. Then I tightened up the vice as tight as I could, and gently flycut the surfaces.

After a while I ended up with this,

Then I set up my very delicate and expensive vice stop, and after marking up the bearing blocks I set about center drilling and then drilling 4.8mm and

then 5mm, all 4 blocks.

Resulting in this,

Now, getting impatient I carefully deburred the holes and whipped out a length of 5mm stainless rod and, aligning the blocks, I quickly shoved it through

and immediately tried to turn it. Imagine my joy to find the rod spun freely....... But hang on, it spins a bit too freely  :scratch:

And it kinda wobbles a bit too 

I immediately double checked the drill to make sure, yep it was 5mm. Then I checked the stainless rod with 1st calipers and then my digi micrometer,

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #3 on: July 20, 2012, 09:57:35 PM »
Part 4.

I started today working on the bearing blocks. I have decided to go with ball races, here they are nest to the blocks,

With the mill still set up from drilling the bearing blocks I 1st of all drilled through each block with a 5.5mm drill to give clearance, being careful to clean

the vice, parallels and vice stop between each operation to make sure the blocks went in the vice in exactly the same position.

Then I mounted a 7.5mm drill, set up a depth stop and drilled both sides of 2 bearing blocks and one side of each of the other 2 bearing blocks. ( when

drilling the double sided ones I was careful to deburr each side before re-clamping to drill the other side, drilling seemed to raise a burr that I fear

could've thrown off the accuracy )
I then followed up with a 8mm endmill to finish off both the diameter and the depth.

Here they are in the bearing blocks,

Anyway, I then marked, drilled and tapped the mounting holes on the bearing blocks. Then I turned down the bosses on the bearing blocks. I turned

bosses on both sides of the inner bearing blocks, and just the one face ( the one facing inwards ) of each of the outer bearing blocks.

I got a little more done today, started off by hacksawing a piece of 2mm brass for the baseplate, then sized it up on the mill. Then I slathered it with layout

dye and marked it up.

Then it was over to the mill and I drilled all the 3mm holes and then all the 2.5mm holes, then I mounted the bearing blocks and marked up for the cutouts.

Over to the mill again to mill out the cutouts.

The obligatory posed shot

I got a little more done today, somewhere inside both of these lumps of brass there are 4 crankwebs and a flywheel, my mission, should I choose to accept

it, is to find them.

So I hacked off a length of the long bar and chucked it in the lathe, faced it and turned it down to 28mm. Then I centre drilled and then drilled through

progressively to 4.9mm drills, then finished it off with a 5mm reamer. (I guess this was a little overkill but I thought is would result in a good fit for the


I then chucked a 4.5mm drill in the tailstock the wrong way around and just positioned it so that it just stuck into the hole in the brass bar. Then I parted off

a 5mm section, and rather than it dropping into the swarf it just got caught on the backwards drill. Then repeat for the other crankwebs.

Then, after de-burring the parted off crank-webs, it was time to make another jig for drilling the holes for the big end pin and the little

compression-hinging-hole-thingy. I made the jig as per the instructions in the plans. I drilled all the 2.5mm holes first, then using the pin to lock the disc I

repositioned the x-axis and drilled all the 4mm holes.

And so I ended up with this,

You may notice that one of the crankwebs is not as good as the others. When parting off the carriage moved slightly, but it's not too bad ( a blind man on a

galloping horse would never notice) I think I might be able to salvage it.

Got a little bit more done today, spent a bit of time hunting around for a 0.5mm shim for setting up for milling the balanced areas of the crankwebs. Spent

about 15mins, but came up with nothing. Then I remembered the set of feeler gauges that I got years ago when I was building some guitars, ok they were

imperial, but with the help of a digi-mic I was able to sort out 2 pairs of feeler gauges that equaled 0.5mm.

After milling both sides I cut the slot on each crankweb. Then I drilled, counterbored and tapped M2.5 for the clamping screw.

Then I turned down some brass to make the flywheel.

Next is finishing off the flywheel, I'm a little undecided as to doing a lot to the visual design of it as, looking at pictures of the finished engine, the flywheel

is not as obvious as some other engines.

Quote from: NickG
Presume the crank journals set 90 degrees apart on this engine? Do you have a method of achieving this or just by eye?


Hi Nick, yes, as I understand it ( and that is quite a statement  ) the cranks are set at 90degrees. I think that it is set by trial and error ( in my case, probably

more error than trial ) I could be in error in saying that, I have read through the plans a few times but I have the memory of a fish.

I got a bit more done today, worked on the flywheel recess.

I started off by re mounting the flywheel in the 3jaw, I wasnt too worried about it being precisely concentric. I ground up a new Hss blank to do the job and

then had at it.

I then changed tools to a 6mm round profile and put a little radius to take the sharp edges off.

Then I had to tackle putting the 3 holes in the flywheel. This meant breaking out the rotary table. I now have yet another item on my "To Make" list, as I

need a means to attach my 3jaw self-centering chuck to the rotary table. But until then I have to make do with a slightly more convoluted means of

attaching items to it.

So then, how does one secure a round item, ie my flywheel, to the Ro-Tab and get it centred up?

Well this is how I did it, there's probably many other ways, and maybe easier ones too 

I eyeballed the flywheel into the center and attached with 2 clamps, but only tightened them thumb tight. Then mount a Dti on a mag base mounted on the

table, with the finger set against the inside of the 5mm mounting hole. Then just rotate the table and "bump" the flywheel ( or whatever you are centering )

until the Dti reads the same all the way round the flywheel, or within reason ( I haven't finished the outer edge of the flywheel yet, so it still has some

marks which bounced the Dti needle a bit, but I just got the reading at an average all the way round it )

Then drilled the three 4mm holes at 120degrees spacing.

Then I drilled and tapped m3 for the securing screw.

And this is the resulting flywheel,

Got a bit more done, started work on the crankshaft rods, I only had 5mm stainless ( got some 4mm stainless rod on the way ) so I just cut the 3 lengths of

the 5mm, sized them on the lathe and then polished them while still on the lathe with some wet-n-dry.

Then I set up the spin indexer on the mill and milled the 2 flats on the longer 5mm rod, and then the flat on the other one.

Then I moved on to the eccentrics, I grabbed some steel and chucked it on the lathe. Turned it down to 18mm and installed the 4mm groove's on each


Got a bit more done today, got some 4mm stainless rod so I cut off 2 pieces for the big end pins.

Then I turned to the eccentrics, and the slight problem as how to hold them in order to drill the offset hole in both of them. It occured to me to try clamping

my little 3 jaw self-centering chuck directly onto the mill table, and what do you know, it worked!!

Then after drilling both, it was back over to the lathe to re-mount them using a 5mm rod that was tapped M3 and a M3 screw.

After a little turning

One lesson I have learned is to keep your mouth in the closed condition when turning steel (or other metals too), if you think the little chips are a bit hot on

your bare arms, wait til you get one shoot into your mouth 

Anyway, after that I drilled and tapped the fixing holes, then I discovered that I dont have any M3 grub screws left, so at the moment the eccentrics are

fixed by faith. Being the excitable type I quickly assembled the bottom plate, bearing blocks with ball races, crank assembly (in my hurry I mounted one of

the crank webs the opposite way round to the others, it doesnt make a real differance I think, but it looks a bit odd) and flywheel and eccentrics.

Whoo hoo!! It's starting to look more like an engine and less like a collection of parts 

Quote from: Bogstandard

For the low block, just shim it up with layers of bacofoil, it might only need one or two. But get it before you have done the Sunday roast in it, less crinkles.

If you start to try bringing the others down to match the low one, you just might make it even worse.


That's a good point, I'll try the tinfoil shims 

I got a little more done today, I got some temporary ( unless I can't come up with a fancy blingy design ) columns. Nothing fancy here, just some plain

stainless rod cut to length and then tapped m3 at each end.
Then I cut up a couple of pieces of 4mm stainless for the Little end pins and single pointed one end of each piece m3, then cut a small slot for a

screwdriver in the other end.

Then I got excited again and assembled the top and bottom

It's looking more like an engine now 
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #4 on: July 20, 2012, 09:58:04 PM »
Part 5.

Got a couple of hours in the workshop today, started on the con-rods. I decided to try a little something different and used some brass Hex rod. I then

marked up for drilling the 2 holes. I set up and drilled the 1st hole in both con-rods before repositioning the y-axis using the dial to make sure the spacing

would be exact.

While I was worrying about getting the holes precisely at the right distance I neglected to make sure the hole's were exactly on centre on the flat of the

Hex  :bang: But it should be ok, I cant notice it with my eyes closed 

Here's a pic of the setup for drilling, I dont have a hex collet so this was the best way of holding the hex bar to drill perpendicular to the flat of the hex. I

squared up the hex rod with a small square and then tightened the vice up.

I then made up a little filing button ( my first forray into the world of filing buttons  ) and then used it to round over one end of each con-rod.

After that I only had a few mins left before I was called to do "more important things", so I cut down some 19mm square brass bar for the 2 steam chests

and milled them to length. Next time I'll be breaking out the little flycutter to bring them down to the final dimensions, and then the fun starts when I start

boring it out.


Since getting this engine to run I have found a number of places that can cause friction, one of which is my design of Con-rod would tend to catch on the

crank-webs. But the fix was very simple. I just put a m4 threaded rod in the chuck and placed the crankshaft end of the conrod over it and tightened a nut

to hold it on. Then I just shaved about 0.5mm off the side of the conrod to leave a little boss. Then flip the conrod over and do the same.

This really helped ease the friction and catching issues with the conrods.

I started off today by flycutting the steam-chests down to size, then I marked up the Datum end and drilled the hole for the spool valve using progressively

larger drills until I got to 5.9mm.

Then after marking up one side for the steam inlet flanges I set up a stop on the vice and drilled the 1st hole on each block, using a vice stop ment that it

was easy to find the 1st hole, drill it and then swop over the steam-chests to drill the same hole in both without having to measure and re-check. Then it

was just a case of winding on the x-axis the right amount for each hole.

Both chests

Well I started off today by drilling the thru-holes for attaching the steamchests and for the steam porting, and then tapping the inlet flange fixing holes.

Then it was time to use a 6mm machine reamer to clean up and finish off the piston valve bore's. Prior to this I have only used hand reamers that kinda

centre themselves just using a tap wrench to turn them. However, machine reamers are a different kettle of fish ( or so I am led to believe ) they need to be

accurately aligned to the bore.

This was still a new experience for me, mounting a previously drilled item back into the vice and then centering it accurately to the spindle. So this is how

I did it.

I mounted a Dti in the chuck but offset it slightly on its mounting so that the spindle can be turned 360 degrees and the finger will still stay in contact with

the wall of said hole. Then by sweeping it round and nudging the x and y axis until the needle stays still through a whole revolution. Then lock up the axis

and  :doh: watch the needle deflect, unlock axis and estimate deflection and then compensate and then re-lock. I managed to get it to within 0.005mm

which I thought was ok.

This may be a little offtopic but I thought I'd just share a little thing I do when removing or changing tools on my little mill. I dont know if I'm the only one,

but when changing tools it seems like you need about 4-5 hands, one to hold the tool in position, one to hold the spindle lock and one to tighten up the

chuck, and if that is not hard enough, when it comes to remove the tool, say an end mill, you have one hand holding the spindle lock, the other is pulling

on the spanner to loosen the chuck, then as soon as you loosen the chuck by what seems like a gnat's whisker, said end mill drops at the speed of light

and drops on the vice chipping at least 2 of the cutting edges/teeth, whereupon the endmill will bounce onto the concrete floor. Do this a couple of times

and it can get kinda expensive. So this is what I do.

Just lower the mill's head and rest the tool on a sacrificial piece of ali so that the tool cannot fall completely out of the chuck.

I'm sure that all you experienced machinests out there do this or an even better method, but this is new for me.

Anyway, back on topic.

Then I broke the whole engine assembly down to bits as soon I would need to work on the main block to drill and tap for the steam chests. That done I

milled away some decorational clearances at the top of the steam chests. I still have a little shaping to do to these as can be seen from the hatched

markings. This is just a rough marking, I reckon I can't go quite up to the line as it may break into the main bore of the piston valve, but this gives a rough

idea of what I'd like to achieve.

Then my friend Stefan popped round and gave me a helping hand.

Together we rough cut some 2mm brass sheet for the steam chest blanking plates, then we milled them into shape, and then we milled a 3rd one to

replace the rather diamond shaped one we cut earlier without properly squaring it.

Then, lacking some superglue to temporarily hold the blanking plates to the chests, we used an engineers clamp ( at least thats what I think its called ) to

clamp the plate to the chest and then spotted thru to mark the holes, then we drilled both plates.

Then it was on to drilling the main block for the steam chests. With the lack of superglue spontainiously appearing in the workshop, and with the whole

block and steam chest arrangement being too long to use my engineering clamps on, we mounted the assembly into the vice, carefully lining everything

up while tightening up the vice. ( having an extra pair of hands was very helpful here )

But this meant that we could only spot thru on the upper mounting holes, this we did on both ends of the block. Then we drilled and tapped the 2 upper

holes of both ends. Then we were able to mount the steam-chests using the top mounting holes with some M2.5 screws and then when all aligned up right

we spotted thru the bottom mounting holes, and then drilled and tapped those holes.

Finally after all that we ended up with this.

I got a little more done today and got the 2 piston valves made.

Started where me and Stefan left off, having just faced and drilled the 24mm deep hole. So I turned around the piece and faced off the opposite end to the

required length, 46mm as I recall :scratch:. I then drilled it with a 2.1mm bit and then tapped it M2.5 ( I know the plan said to drill 2mm, but not having the

same confidence with tapping stainless, I just went with a slightly bigger drill to ease the strain on the tap. According to the tapping chart I have, 2.1mm is

still a strong fit )
Then with a bit more of the 6mm rod sticking out of the chuck, I turned it down to 4.05ish mm for a length of 26mm, then polished it down to 4mm with

some emery. It actually has a very slight taper, I say slight as when measured with a mic it tapers from 4.013mm to 4.006mm, I figure that it wont make too

much of a problem ( he says hopefully  )

Then I re-chucked it, gripping it by the 4mm end and faced the free end to leave me with 19mm of the 6mm diameter left. ( my measurements according to

the plans were 18.97, but the plans said it's better to be slightly long so I went for 19mm) Then after marking 3.5mm from each end of the 6mm diameter bit

I roughed out the centre bit, and then slowly brought the 2 ends to 3mm. Here's a shot of the 1st end brought to size.

Then I did it all again to make the 2nd one.

Then it was time to drill the little cross holes and so I used the spin indexer to hold the valves as I centre drilled and then drilled thru with a 1.5mm bit.

That's all I got done, next will be the eccentric straps, and that will plunge me into the world of silver soldering. ( that reminds me, I must pick up a couple

of firebricks to make a hearth. )

EDIT 13/03/2010 (for those reading this thread and wanting the build this engine.)

I have been trying to get the engine to run and had nothing but escaping air to show for my efforts. I have traced the problem to these piston valves. I

originally used 6mm stainless rods to make the piston valves out of, having just now measured the piece of 6mm rod used to make them I find that the rod

is actually 5.9mm and that 0.1mm allows a lot of air around it.

So beware when using raw material to make sure that it is the size you need. I ended up turning down some 8mm steel to make the replacements.

EDIT 6/8/2010

Something I have found when trying to get this to run is a problem with the piston valves sticking, and I eventually chased down the problem. It seems that

when you drill the cross-drilled holes there is an edge raised up around the edge of the hole. The solution was to just give the piston valves a Light wipe

with a fine cutting file and then a wipe of some w&d while they rotate at a slowish speed in the lathe.

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #5 on: July 20, 2012, 09:58:37 PM »
Part 6.

Well I've spent a bit of a frustrating afternoon. I started off ok with cutting out some 4mm brass for the eccentric straps and then milled the pieces square

and to size. No problem there.

Then I set up a vice stop and positioned the mill table for centre drilling all 4 parts, and then centre drilled all 8 holes ( keeping up are we ?? ) That went

ok too. Then I started by drilling the 2mm thru holes, and this too went ok until the last hole when the 2mm drill bit snapped halfway thru. "Easy" I thought,

just turn over and drill thru from the other side. So I turned it over, centre drilled and then very cautiously drilled thru using the same bit that broke (

having just resharpened, well re-shaped the broken end on the grinder freehand, probably not that sharp and definately not the same profile, but it was

good enough to finish a hole that was half bored, or at least that's what I thought)

I gingerly drilled thru to where the old bit was stuck, and hearing the telltale sound of drill on harder material ( hitting drill not brass ) I withdrew the drill

and knocked the drillbit fragment thru with a fine punch. Then to finish the hole off I attempted to drill through with the same re-sharpened bit. Wouldnt

you know it, the darned thing snapped the drill again  :bang: :bang: Fortunately the hole had been drilled enough and I just had to knock out the 2nd

broken bit. So I thought that must be all the problems over and done with 

Then I started on drilling the blind holes that are to be tapped, and got the 2 holes in the 1st eccentric strap drilled without any problems or drama at all.

Then I think it was at this point that I must have been getting too smug with my own ingenuity in overcoming all the preceding problems, thinking that

everything's just so easy and plain sailing. I was drilling the 3rd 1.6mm x 6mm deep hole ( to be tapped M2 ) when the bit snapped  "not another bit!!!".

After a bit of head scratching and thinking of how I could recover the part it occured to me that I can just bore the holes in the other end and cut off the bit

where the snapped off bit is when I shape the top of the strap.

I didnt have a spare 1.6mm bit, but checking my tapping drill chart I saw that 1.7mm is ok so I drilled the opposite end and then tapped the holes.

Now here's a kick in the teeth, Just after tapping the M2 holes I happened to turn over the part and you wouldnt believe it, the darned broken bit of the drill

had fallen out 

Not taking heed of all the signs telling me to quit while I was behind, I pressed on and made a start on boring out on of the straps. I didnt have any M2

screws that were long enough I used some M2 allthread and some M2 nuts. Not having the stepped cutter that John used, I progressively drilled out to

13mm ( my biggest "small" drill ) and then used my boring bar set to enlarge to a little over the size of the smallest eccentric.

Taking it out of the vice and seperating it I then found that the eccentric groove is every so slightly smaller than 4mm :bang: Not having a way to chuck the

eccentric to slightly enlarge the groove, the only other option is to reduce the thickness of the strap a tiny bit. The strap fits the eccentric, but it is a press fit

and totally impossible to rotate. I've sanded it down using some W&D on my granite plate, but it's not reduced enough.

I guess I might try flycutting it down by a tiny bit. But at this point I decided to heed all the signs and retired for the day. Sorry for no pics in this post, but

when all started to go wrong I forgot about taking pics.

So, not much progress to show, but I guess I've learned from the experience.

A couple of photos of the eccentric straps so I thought I'd share them.

These are the straps before I started on the whole thinning and then boring the holes for the eccentrics.

And this is them after much sweat, tears and tantrums, well, sweat and tantrums anyway.

You can see the extra holes that I broke the drills in as mentioned before. I will be cutting those portions away when I shape the straps.

So I got a bit more progress made, Stefan came over last night and we got some work done on the eccentric straps. We started by drilling the 3mm holes

for the connecting rods, and with that under our belts we carried on to drill the little oil-cup-hole-thingys. It was at this point things started to go a little


1st off we discovered that my 1.5mm drill bit is as sharp as a kleenex (mansize of course), so after burning a 1mm deep hole we switched to a 1.4mm bit.

This went through the brass like, well a sharp drillbit through brass. We drilled thru with that then we followed up with a 2.5mm bit to a depth of about

5mm to make a little resovoir-cup-thingy.

Now riding on a crest of a wave, congratulating ourselves on making such a fine job of the 1st strap, we ploughed on to the other one. The 3mm hole for

the connecting rod was installed without a hiccup, and the 1st 6mm of the 1.4mm oil hole went swimmingly, and then  :bang: :doh: :bang: :doh: The drill

snapped. Cursing this unknown grade of brass sheet for being so tough we were forced to stop. ( We had been drilling using top speed (about 4800 rpm )

and also were "pecking" taking about 0.5-1mm per "peck" )

After a little thought we decided to try drilling thru from the other side, sounds simple except this meant drilling from the inside curved surface where the

eccentric would sit. After carefully marking out where the hole should come out we started with a tiny centre drill at full rpm's and very gingerly started the

hole. After about 1mm depth we switched to a 1.3mm bit ( crumbs, if I break any more on this the oil hole will be <1mm!! ) and again very carefully drilled

thru to the broken bit ( if you are very gentle you can hear when the drill gets to the broken bit ) then withdrew. Then, using a thin awl we gently tapped

the broken bit thru until it fell out.

It's funny how things can go wrong on the final operations on a piece, but we figured we had little to lose by making this attempt at a save, and it turned

out ok. Here's a pic looking down on the 2 halves of the straps as we left them last night.

Then this afternoon I got a bit more done on the shaping of the straps. I milled away a little on each strap and ended up with something that looks a little

art-deco ( completely by accident mind you ).

Then I turned down some 4mm brass rod to 3mm and cut off 2 18mm lengths for the connecting rod for the straps.

Quote from: bogstandard

Really I think you are taking things a little too literally.

The oil hole is just that, a place to wack a bit of oil into. It could have been a lot larger, within reason. It was just a way of reminding people that it is a

hole and it is there for a reason. When lubing up the engine, you see a hole, what is it for?, you remember that a spot of oil is needed down there

occasionally, job done.

It is only when you use a calibrated drip feed hole from a small reservoir that you need to worry about things like that.

But coming along just fine now, you will soon be ready for the first air trials.


Ahhh!! I didnt know that it could've been made bigger. That'll be my inexperience with engineering-type-stuff showing thru again, oh well, everybody has

to learn, I've learned from this, and hopefully others can read this and learn from this too.

I do have to say, even though an awful lot of this is very new to me, and there have been some frustrating moments that make you want to chew your own

foot off, all in all I am absolutely loving this!! And being able to share it all with the rest of the forum and benefit from the collective wisdom and advice is

great too.

I got a little more progress made this morning, starting with the blocks.

I started out by cutting off a chunk off the same 4mm thick sheet (well, hardly a sheet, more like half a hankichief) of brass that I made the eccentric straps

from. and then mounted it the mill-vice to make the cut edge flat and parallel.

Then after a little cutting to size and milling I ended up with these

Then after a little drilling they were done, here they are in place ready for silver soldering. ( I plan on doing a few practice joints before attempting to SS

any of the parts for the engine, just to be on the safe side.)

Just on the subject of Silver Soldering, and especially to those who have built the Paddleducks engine, how did you stop the silver solder from blocking up

the oil hole on the eccentric straps? The oil hole is only about 1mm from the soldered joint for the con rod. Any hints or tips?

Anyway, getting back to the build.

After this I had a bit more time, so I made a start on the Forks ( "use the forks, Luke" (said in best Obi-Wan impression)  :lol:  )

Not having any 6mm square brass stock I sliced off a 8mm chunk of the 19mm square bar I have, flycut it on both sides to 6mm thick, then cut it down and

milled it to 11mm on one side, then cut the other side ( the remaining 19mm side ) down and milled it to give me 2, 6mm x 6mm x 11mm blocks for the


So next time I will be drilling, tapping and milling the forks into shape, then it'll be on to the valve packing glands ( which I already have made the nuts for

thanks to Kvom  for telling me that they were the same as the piston packing gland nuts, so I made extra when I made them.)
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #6 on: July 20, 2012, 10:00:29 PM »
Part 7.

I got a little more done today on the forks.

I started out by mounting one on a parallel ( that's right, just one parallel as two were thicker than the fork itself ) in the vice and then milling out the

middle with a 3mm cutter. I did toy with using a 4mm cutter as that is the desired slot width, but then I remembered reading that when milling a slot, a

cutter of a given diameter will often cut oversize when it is cutting on both sides at the same time. Well as you can see, these forks are only 6mm wide and

I didnt want to risk making the side walls of the fork-bit too thin, so I used a 3mm cutter and then just took an extra pass across each inner side of the fork

to make the slot 4mm with the walls 1mm each.

Then it was on to drilling and tapping. The forks are drilled and tapped thru, M2.5 at the top end. So mounting them in the vice they were centre drilled

and then drilled thru 2.1mm. I left them in the vice to tap them, I just wound the x-axis to one end to give clearance and then put my tapping stand next to

the vice and swung the arm over to tap the holes. I did this as I dont have a vice for my tapping stand yet, and holding these little pieces by hand would

not have worked out so good for tapping squarely.

Then it was time to roll out my latest version of my vice stop.

( by the way, that hold-down is only tightened up just enough to hold the 2 parallels in place, I reckon if it was tightened up real tight the whole lot would

not be very stable, but this setup allowed me to have the whole of the fork gripped by the vice while I gently drilled thru for the pin to hold it to the block

on the eccentric rod )

After all those shenaninaninanigans  ( drumroll please ) is a finished fork. The overall dimentions are 11mm tall by 6mm by 6mm.

And here are both of them with the eccentric assembly's

Onwards and Umm, sideways? 

I decided to get on with making the packing glands for the piston valves.

I started off by taking a bar of 20mm brass rod and chucked it up in my ER32 collet chuck on the lathe. Fortunately the bore of the headstock allowed me to

chuck the whole length ( about a foot, give or take a few mm depending on the size of your shoes  :lol: ) and only have a little sticking out each end.

Then after turning down a section to the required 16mm, I then turned down a 6mm length to 8mm diameter, centre drilled it and then proceeded to drill a

5mm hole about 6mm deep.

Then I tapped the hole M6 for the packing nut ( or should that be packing screw  as it screws into the packing gland )

Much earlier in the build when I was making the packing glands for the cylinders, Kvom very kindly mentioned that the gland screws for the cylinders are

identical to the gland screws for the valves, and suggested that when making for the cylinder glands it would be an easy thing to turn out a few extra for

later on. I took this advice and made 3 extra ( 1 to break or lose and 2 to actually use).

All that meant that rather than having to make the gland screws today, they were already made. So now I took one of the 3 previously made gland screws

and screwed it into the newly tapped hole, then centre drilled it and followed up with a 4mm drill and bored all the way through to full depth, thus (

hopefully ) resulting in the hole being concentric to the bore that it would fit.

I used a little depth collar on the 4mm drill so that I would not go too far into the parent material.

Then it was just a case of parting off from the main brass rod and repeating the above.

Or so I thought. All was going well until I got to the point of drilling the 4mm hole in both the packing screw and gland. I drilled thru the screw ok, but as

soon as the bit started to drill into the actual gland, the head of the gland-screw sheared off. ( I reckon that I made the undercut at the end of the threaded

portion just a little too deep, and so with the 4mm hole up the centre there was just not enough holding it together, and so with the vibration of drilling

along with the friction of the drillbit, it just let go )

Thankfully the threaded portion was not jammed in the gland, so I was able to gently unscrew it using a little dental-pick-type-tool. Then with some

trepidation I screwed in the last of the gland-screws that I had made, and again drilled it. It went ok this time, drilled thru, parted off, and then reversed the

gland in a 8mm ER32 collet to clean up the face that would sit against the bottom of the valve block, and also custom fit the little 1mm flange that locates

the gland into the valve bore.

And this is the result. ( also shown is the broken gland screw )

So one more step done, next I will be drilling the glands for the mounting screws, and then drilling and tapping the valve blocks for the same mounting


One thing I would say to anyone who is also building one of these, dont just make one extra gland screw, make 2-3 extra. It wont take very long to make

an extra one or two, but it could save a lot of time later ( and a lot of sphincter tightening when you are working on your last "spare"  )

Well I managed to steal a bit of an afternoon in the 'shop and got a little more done. I started out by taking the jig I made earlier to drill the mounting

holes in the piston glands and adapting it to drill the mounting holes for the piston valve glands. ( basically turned the jig upside down and drilled a 6mm

hole a few mm deep to locate the gland into, then drilled the glands)
No pics of this as it is virtually identical to drilling the piston glands ( and I got carried away and totally forgot about taking pics until just before I came

back in the house )

Then I used John's tip of alligning and then fixing the glands to the valve blocks with a drop of superglue, letting it set and then spotting thru to mark the

holes. Then after a blast with the fire-producing-monster, a quick wipe over with a rag while still hot, and the parts were seperated and cleaned up. Then I

drilled and tapped M2 the valve blocks.

While I was waiting for the glue to set I turned the little connecting pins that attach the whole eccentric strap assembly to the actual piston valve. I turned

down some 4mm stainless to 3mm, and then turned down a 4mm section of that to 2mm ( actually just under 2mm ) and then threaded it. Then I parted it

off leaving about 8mm of the 3mm diameter section, and repeated the whole process again.

Then I chucked each pin with the M2 threaded end facing in, and faced each pin to length.

Then I had another little job to get done for a friend and so that is as far as I got today.

One thing I did come across was this little parts organizer that I got months ago. It is just the thing to keep all the tiny parts and screws in for a project like

this, I think I'll order some more of the larger sized one ( this pic shows 1 set of small and 1 set of larger compartments, they are all interlockable or can be

all seperated if you like) They are great as they have individual lids that latch closed  or open.

I got them from dealextreme, Here and


Well I got a few moments in the workshop this afternoon, so I got a little more done on this.

I have to admit that I had been kinda putting off the silver soldering as that is something new and unknown to me, but this afternoon I decided to have a

go. So getting out the citric acid I made up some pickle, then I mixed up some flux (tenacity 5 if my memory serves me right) and got out the SS and


Rather than try my first joint on a real part I took some scraps of brass, drilled some holes and used some 4mm brass rod. It wasnt as bad as I thought it

was going to be. It took a couple of attempts but I got there in the end.

Feeling elated from this I made a start on soldering up the eccentric straps to the con-rod to the little con-block. I had read about how it is good to have a

slightly slack fit when soldering, I now know from experience the value of this. I had decided to try and solder the whole assembly in one go, and so had

cleaned and fluxed both holes ( one in the eccentric strap and one in the con-block ) and both ends of the little rod, and put them together. Applying the

heat to this, first of all gently to evaporate the water in the flux, then with a bit more heat. It was while this second phase of heating that there was a sharp

"crack" sound and the con-block decided that it would violently leap at the wall and bounced off, landing quite neatly on the floor directly underneath the

rest of the assembly.

I guess that there must have been a bit of water/steam/gas that had got trapped until it heated up enough to propel the block off the rod. Taking this as a

sign, I decided to solder one end at a time, and it worked out much better, if a little longer to do.

Then I attempted to do the 2nd eccentric assembly. I gave soldering both ends at once another try, but this time drilled out the holes to a slightly larger

diameter. This seemed to work much better except that just when the solder started to flow, the con-block (I'm not sure that is the right term for it, but I've

used it enough for it to stick :dremel:) started to move a little off the rod. :bang:

This is them after being quenched.

Those of you who are not completely blind will see that there is approx 2.3mm height difference between the 2 assemblies. I dont know if there would be

enough adjustment to compensate for this, or whether it would be better to re-flux and then reflow the solder and just push the 2 pieces back together?

:scratch: (any and all thoughts would be welcome)

Anyway, I have learnt that silver soldering is not all that hard, but that I do need to practice a bit more. Also learnt that you need to get the workpiece

much hotter than I originally thought would be needed.

I did notice that when heating up the joint, the flux 1st of all will evaporate the water in it, going white, then it darkens to the point of looking a bit black

(perhaps I am burning the flux? ) then it goes clear and you can see it cleaning the metal, then the solder flows. Does all that sound about right to you

guys who are experienced with SS?

I have managed to fix the SS joints that went a little wonky by doing as Bogs suggested and heating the piece up and then compressing the joints

together, then laying it flat and pressing the whole assembly flat.

That was about 3-4 weeks ago. Since then I have only been able to get into the workshop for fairly short periods of time, about an hour at a time.

I have temporarily halted the paddleducks build as I have pretty much got to the point of making up the pipework and flanges, and I want to go with bent

pipes instead of the extended flanges that the plans call for. So that meant that I needed a pipe bender. John ( Bogs ) was kind enough to send me some

plans for a pipe bender, and I have made a start on constructing it.

Yea, yea, I know I should have taken some pics, but because of only being able to get short times in the 'shop I have been forgetting to take the camera

out with me 

Anyway, I will try and take the camera out the next time to show you what I've got done so far ( which isnt that much  )

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #7 on: July 20, 2012, 10:01:00 PM »
Part 8.

Well, having managed to finish my pipe bender ( well, I got it to the point that it can bend pipes, it isn't finished in the "by the plans" sense of the word, but

it works good enough for me) I have got back to this build ( finally  )

Today I got started on making some pipe flanges, the plans call for making the "stand-off" type pipe flanges to withstand the pressures of machining. But

because I am using bent pipes I decided to make them out of brass.

I used some 12mm brass rod and parted off 4 thinner ( about 2.5mm ) pieces and 2 slightly thicker pieces (about 3.5mm ).

I then made up a split collet to hold the "flanges" while facing both sides to thickness and smooth, and drilling the 4mm holes. I was pleased to see that

using the split collet in an ER32 collet worked well.

Then it was over to the mill, where I used the split collet again to hold the sized flange blanks to drill the mounting holes. I clamped the split collet in the

vice with a very expensive vice stop  :lol: and put one of the flange blanks in it, and centred it by putting a 4mm drill in the mill (switched off) and then

adjusted the x and y until the drill would drop in and out without friction. Then I swapped over to a 2mm drill, moved the table over by 4mm, drilled and

then moved the table back by 8mm to drill the other hole, and then repeated for the next 5.

And here's the result along with the split collet.

Here's a mock-up with a bit of bent 4mm pipe.

Next I have to mill the sides of the flanges and then silver soldering the pipes to the flanges and also bending the pipes.

I forgot to post up some pics of my pipe bender.

John (Bogs) kindly sent me some plans for this bender when I mentioned that I would like to try using bent pipes instead of using a machined stand-off,

and for the last few weeks I've been working on and off ( more off than on ) on building it.

I have stuck loosely to the plans in some areas, and not at all in others due to not having hardly any raw stock that was called for in the plans. I didnt take

any "in-progress" pics, sorry.

Here's some pics for your enjoyment,

One handy hint I can pass on is with regard to turning the brass forming wheels. I ground up a form tool to a rough outline of a 4mm half circle, but slightly

smaller. Now here's the handy hint, it only works for 4mm tubing/pipe, but to finish off the round grooves in the forming wheels to a perfect finish, get a

hold of a chainsaw sharpening file, they are round and are 4mm in diameter. Stick one in a file handle and then it just takes a few strokes while the lathe

is running slow to finish off the grooves. I also made 2 slightly different diameter sections on each wheel to give a slightly smaller radius of bend to choose

from. ( if I was to make it again I would make the difference greater )

I also fabricated up the main handle from 2 pieces of 3mm steel and a lump of cast iron. I tried to silver solder it all together, but not having made a hearth

for silver soldering it took about 10 mins, blasting it with the torch. I wasnt sure that the silver solder had taken, so I drilled and tapped M5 to re-enforce it (

so far it has held without putting in the M5 bolts ).

I also did not bother making the rest of the clamp as the plans called for. They call for taking a 2" length of 1" square steel bar and machining and turning

most of it away. Not having any steel square bar, nor was I looking forward to machining all that away too. Standing looking at the plans for a while it

dawned on me that there is no real requirement to make a clamp for it, a standard engineers clamp will do the job just as well, and I didnt have to spend

any time making it.

I dont anticipate having to use this bending tool too often so I think just using an engineers clamp will do me just fine.

So I got a little more progress made today. I milled the flats on the flanges using 2 2mm drillbits to position them in the vice.

That done I got started on bending some tubing. At this point I realised that the radius that I was getting with my bender was not tight enough, so I decided

to reduce the diameter of the smaller section of the bending wheels by 1.5mm depth ( 3mm total reduction ), this proved to be just right so it was on to

making the bent pipes and silver soldering them on to the flanges.

The silver soldering went ok, there was a 2 flanges that I had to redo, I dont think that I got the joint clean enough on those 2. I did find it amazing just how

soft the copper tubing gets just after soldering, it's very easy to make the straight sections wavy by just handling it

Then after dropping all the flanges into the pickle for about 20 mins I fished them out and gave them all a gentle clean with a grubby cloth to get rid of the

remaining flux, I finished off by trimming the tubing sticking through the flanges with a hacksaw, filed them, and finally a quick rub on some 360grit w&d

on a flat surface to polish the faces of the flanges flat.

Anyhoo, here's the obligatory pic of the finished flanges with tubes,

Next will be onto the steam-control valve, that's bound to test me as it seems that you have to be very accurate with making the spool. I'm pretty good at

making one part to an accurate size, but getting both the valve-control-block and the spool accurately made will test me a bit more.

Today I realised that I have been a bit skimpy on the pictures, so when I went out to the workshop I was determined to take more pics

A few days ago I had a few mins and so dug through my little pile of materials and found a bit of brass bar, round bar as I didnt have any square brass bar

of the right size.

Then today I stuck the cut-off piece in the mill and started to turn ( he he he ) it into a square.

After a little while I ended up with this.

But as you see, the end mill left a rather rough finish, so I left a little extra "meat" on the brass block and then switched over to the mini-flycutter.

Once all edges were silky-smooth and sized to requirement I set the block on it's smoothest face and flycut the opposite face, then flipped it and repeated

the process to size the block to thickness.

Once the block was sized I set out to mark up the edges for drilling all the various steam holes. Then I set up a vice-stop.

One thing I have discovered when using a vice stop ( that you guys probably already knew ) is that it seems to be better to set up the vice stop before

putting the workpiece in the vice, otherwise it is very easy to not get the vice stop right up against the workpiece. Whereas when you put the stop in first

you slide the workpiece up against it just like you would do it on subsequent operations, the results ( for me anyway ) turn out more consistant ( making

sure to clean the vice area when re-positioning workpieces )

Anyway, back on topic, I set up the vice-stop and then put the block into the vice against the stop. Then using an edge finder I set up for drilling the centre

holes and then centre drilled all 4 edges.

And then drilled

and then drilled the outer steam holes by positioning the drill over one outer site and then switched the block around to drill the other outer steam hole on

that edge.

Then finally I drilled the 1.6mm holes for tapping M2 for attaching the flanges for intake and exhaust using the same method.

Then I started to tap the M2 holes.

And wouldn't you know it, on the last hole the tap broke off while backing it out

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #8 on: July 20, 2012, 10:01:29 PM »
Part 9.

So I got an afternoon in the 'shop today, I started on drilling the larger hole for the actual spool valve. ( sorry no pics of this as I got a little carried away

after finally getting back into the workshop )

So this is all the machining processes on the main valve block done, I blocked up the 2 little holes that transfer the steam to the ports on the engine and

silver soldered them, then filed and sanded smooth.

The valve block,

Then it was on to setting up for soldering the four flanged pipes that I bent earlier, into the valve block. After a little shortening on a couple of pieces of

pipe I bolted the whole to-be-soldered assembly to the main cylinder-block assembly

The eagle-eyed of you will notice that on that pic there are only 2 joints with rings of silver solder on, the reason is that I ended up re-soldering a couple of

times. The 1st time two joints must not have been clean enough, and so that picture is the setup for the 1st redo.

And this is how I actually heated this 1st redo

To keep some heat off the 2 good joints I put a 1/4" piece of Ali' to deflect some heat. However, I proved to be too cautious about not re-melting the 2 good

joints as when I quenched this I discovered one of the freshly soldered joints had not taken.

So, once again I cleaned up and fluxed and soldered the one remaining joint, and thank goodness it worked.

Then it was on to the actual spool valve, I chucked up some 12mm brass rod in the ER32 chuck in the lathe

and had at it until it looked a bit like this

Parted off and lapped to the bore of the valve block with T-cut

And here's both items ( the valve block assembly has only been pickling for 20 mins here, still a fair bit of cleaning up to do )

I got a bit more done today on the flanges for the valve body. I started up by cutting off a chunk of 22mm brass bar,

then I turned down a 10mm spigot 7mm long,

Then reversed it in the ER32 collet chuck

And turned a 1mm deep spigot sized to match the bore of the Valve body.

Then, leaving 3mm thickness on the flange I was parting off, I parted it off. Then it was on to the top flange. I turned another 1mm deep spigot to fit the

bore, drilled a 4mm hole all the way through, then bored a 6mm wide by 0.9mm ( ok, mine turned out to be 0.88mm but lets not split hairs ) recess which is

for a sealing O-ring.

Here are the pair of flanges ready to have the mounting holes transferred from the main valve block, then drilled and the back flange tapped, that will be

the next job.

the other side showing the recess

I got a couple more hours in the workshop today. I started by finishing off the holes in the flanges that I had spot-drilled last time, and tapping the rear

flange. Then it came onto sizing the valve itself. I started by just fitting the valve into the valve body and fitting both front and rear flanges to see how

much was to be removed from the valve spool. Notice the little gap between the body and the front flange.

Then it was over to the lathe to skim off a shallow cut ( about half the size of the above gap ), then re-assemble. Still not there, so back onto the lathe,

another skim, assemble, getting closer. This went on for about 8 times before it got very close. The reason for doing this in tiny stages is that if you cut too

much off you have to re-make the spool, and I thought that taking small cuts and trying to fit, then taking another small cut, etc etc, would be quicker than

having to remake the spool valve from scratch.

Anyway, as the plans suggest, when the valve got very close I switched from cutting with a hss tool to using a piece of 360 grit W&D backed by a flat piece

of metal, to just sneak closer to the right size. The right size was when the spool could just rotate with the flanges bolted tight together.

Once that was done it was time to mill the slots in the spool valve, 3mm wide and 3mm deep slots.

Then the only part left to make is a little handle for the spool valve. I drilled a 4mm hole in some Hex and then I chucked it in the 3jaw, rounded a section

and then filed the end round ( this was a lot quicker using files than setting up my ball turner ), then I set a 5-10 degree on the compound and turned a

tapered section.

Then I cross drilled a 2.1mm hole for the tightening screw, cut a slot through to the 4mm hole and then counter bored a 12mm bore in one side of the 4mm

hole to allow the handle to fit closer to the valve body. Then tapped the 2.1mm hole M2.5 and bored out the opposite side to 2.5mm.

Everything put together.

And I think that is all of the parts made for this engine
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #9 on: July 20, 2012, 10:02:05 PM »
Part 10.

Well I have spent a slightly frustrating afternoon on this engine. I built up the engine into 2 sections, top and bottom, the bottom holding the crankshaft

assembly and the top that had everything else. Then I timed the eccentrics with the crankwebs as per the plans and then assembled the top and bottom

sections together.

Feeling very excited I hooked up the little air compressor and fired it up.....


Lots of air escaping around the spool valve straight out the exhaust pipe. The only thing I can cling some hope on is that I havent put the O-ring in yet, but

I think that is just vain hope. I reckon I will have to remake the spool valve.

Undeterred I decided to press on and just hook up the air to one cylinder at a time just to see if I could get it to kick over. I then found that all those parts

that I made that fitted together firmly add up to an engine that is nigh on impossible to turn over by hand, let alone by air :doh:

I had to remove one of the piston valves and ream the packing nut, and also polish the shaft of the piston valve, then put it back together. Then I tried

again but no joy. Again broke various parts down to free them and adjust, re-assemble and try again.

This cycle repeated itself for about 1.5hrs until I started to get close to finding out how many times it would bounce  so I gave up for today. At the last go it

did give a good kick and tried to go, but it was binding up so it wouldnt give a full turn. I finished by removing the top from the bottom in order to make

sure that the crankshaft assembly will spin freely by itself, then I'll work on getting the valves and cylinders working free as well, then re-assemble the 2

parts and see if it'll run.

Oh, and I've got to sort out the reversing valve, as I mentioned before, in almost all positions it was leaking ( more like gushing ) air straight out of the

exhaust, so the remake looks like it is on the cards.

So, no video of it running yet, but give me some time and hopfully I will get something up for you to see, either an engine running or an engine flying. (

through the air towards a wall-shaped object )

A little update on this.

I discovered what is almost certainly the cause of the escaping air. In efforts to trace any problems I took the top section and hooked up air to one inlet at

a time. I found that one piston valve leaked more than the other, but both piston valves leaked. I dismantled one of the valves and measured the "piston"

part of the valve, and it was 5.82mm. The bore was reamed to 6mm.

No wonder there was a lot of air escaping.

When I made the piston valves originally I made them out of some 6mm stainless rod, or so I thought. I measured the piece of 6mm rod I used and found it

to be 5.9mm.

So this afternoon I remade one piston valve from 8mm steel and turned it down to fit snugly in the bore. After re-assembling the valve assembly to the

cylinder and the whole top section to the bottom section, I then hooked up the air to just the newly made valve and turned on the compressor.

Virtually no leaking air and the engine tried to turn over. There is still some binding in the conrod/crankshaft area that prevents the engine from spinning

freely. I think that I'll have to shave a little off a boss on the crankshaft bearing blocks to give a little extra clearance, and I have to remake the other piston

valve too.

Quote from: kvom
That sounds to me as if the journals and shafts are not precisely parallel.  If you do want more clearance between the webs it might be better/easier to

narrow the conrod ends.

Ding ding ding ding ding!!! We have a winner!!!!!!!!!!!

When fiddling with it today I noticed just that the crankshaft/webs/shafts/ect were not totally in line.

After making a new piston valve ( for the other valve ) and re-assembling everything, re-timing it all and making sure that everything was in line, and (

tempting fate ) I also reattached the fw/rev speed control valve and hooked up the air.

This time the "Ffffffffffffffffffffffsssssssssssssssssssssssssssssssss" was a little less and with a little encouragement it turned over a few times, by this time the

little air-brush compressors tank had been depleted and the pressure dropped below 20psi and the engine stopped. By closing off the speed valve I was

able to build up enough pressure to have a few more rotations.

I think that the speed control valve needs some attention, I think that is where I am losing most of my air, I haven't put an O-ring in there yet, so that will be

the 1st attempt at a fix, then if that doesnt cure it I'll have to remake the spool.

That is a great idea Shred,
Quote from: shred
Before re-making the spool,
I spent yesterday afternoon remaking the spool, it was probably a needed action as when I examined the bore of the speed/direction valve I noticed that it

was not truely round and parallel, so I mounted it up in the vice and took a skimming cut with a boring bar until the bore was properly cleaned up. Then I

remade the spool, it turns out to be about 0.4mm bigger than the original one, but it fits better in the bore now.

When I re-assembled the spool into the valve but before remounting the valve onto the engine, I applied air to it to see if it would shut off properly ( the

previous spool would leak like the titanic even when turned off ) and it did ( apart from a little hiss leaking from the joints, and that is because I have no

gasketing at the moment ) so I think that the remake was needed ( or at least that is what I keep telling myself  :lol: )

It did turn over for a little while ( about 20 revolutions or so ) before stopping, so I think I need to spend some time on the timing of it.

( repeat with me ) We WILL get it working, we WILL get it working 
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #10 on: July 20, 2012, 10:02:27 PM »
Part 11

When I had the top and bottom of the engine seperated the bottom crank assembly was completely free. When assembled there is some friction coming

from the crosshead guide rods, I have one in each pair or rods fastened slightly loosely in order to get it running in.

There is also a little friction coming from the piston valve and pistons, but it does turn over with fingers.

I just had a little look at the timing, it was well out. That sorted there was still a lot of air escaping without doing anything so I removed the speed control

valve assembly and attached the air supply to each of the 4 ports in turn.

This was to allow me to see just where the air-leakage was coming from. I found that there was some leakage from one piston valve, but it would turn the

engine over a half turn or so. However, the other piston valve was leaking worse than the titanic, and wouldnt even attempt to turn the engine over.

This is rather frustrating, I had already remade the piston valve once ( well to be truthful I did remake both piston valves ) and I thought I had made, or

remade, it to fit the bore.

So it looks like I have to remake the remade piston valve  :doh: or at worst it might have to be a remake of the piston valve housing  :bang: :doh: :bang:

Oh well, its all a learning process. I gave up for the moment as I started to get rather frustrated with it all, so me thinks I need to just leave it for today.

Well, talk about resurrecting an old topic :bugeye: I cant believe that it has been over 4 months since I posted any updates.

Due to my better half's health situation, until recently I havent been able to spend much more than 20mins at a time in the workshop, which meant I hadnt

made much progress on this build ( or on much else ). But things seem to have settled a bit to allow me a bit more time in the 'shop so I thought I'd update

this build log.

To date I have remade one (already remade ) piston valve and made a new steam chest for it and succeeded in keeping a much closer fit.

I also have modified the pistons to accept o-rings.

I then started to chase down and fix as many causes of friction that I could.

I bored the bearing blocks all the way through, they originally had a 5mm thru hole for the crankshaft, and a 8mm diameter pocket each side for the ball

races. I have since found that there was some friction being caused by the 5mm sections, so I got all 4 bearing block bored out to 7.8mm in the mill, then I

carefully alligned them all together in the vice and used a 8mm hand reamer to open them out the final 0.2mm. Then I stuck some 8mm silver steel rod

thru the 4 and gave them all a wipe over some 600grit w&d on a surface plate.

Then I loosely assembled the bearing blocks onto the baseplate, stuck the 8mm rod thru them, and then tightened them up. Then I lapped them using the

same 8mm silver steel rod and some T-cut to get them spot on. Then I re-assembled the crankshaft with all the ball races and the difference was

unbelievable, silky smooth and free.

After re-assembling the whole engine and re-timing it I applied some air to it and........

It ran   ( for about 20 secs until my little airbrush compressors tank was empty )

It seems to be quite an air-hog at the moment. I got it started on 50psi and it ran until the tank got down to about 25-30psi. I havent got any gasketing

installed at the moment, nor any stuffing in the glands, so that will be my next process, chasing down the air leaks.

I also have noticed that there is a lot of air that seems to going straight thru the valving to the exhaust without meeting the piston, so that too will have to

be investigated.

Overall I am quite pleased that I have got it to run on my little compressor, previously it had not had enough stored air to turn it over more than a couple of


So while it is taking me ( quite ) a while, it is satisfying that at least there is some progress to report, hopefully in the coming weeks I will be able to post

up a video of it working.
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #11 on: July 20, 2012, 10:04:16 PM »
Part 12.

Well I got another little blast in the workshop this afternoon and managed to eliminate another cause for friction in one of the steam chests. I then brought

my camera in and captured a video for you all to see. ( in HD and all  )

Before you play it I must apologise for the sound, there is still a lot of air escaping and then the compressor kicked in, so it might be worth sticking

something in your ears ( or mute/turn down your sound ).
#Invalid YouTube Link#

After running it for a bit it will self-start on about 35-40psi, and will run on as little as 18-25psi. It runs great one way, and not so great the other, but

hopefully it will bed in after some more running.

It's not too pretty at the moment, and I still havent got any liquid gasket yet, so it still leaks a bit from all the mating metal faces. Once I get it running real

smooth and on lower psi's I will bling it up.

Just a little update on this.

I finally got some liquid gasket stuff, so I disassembled everything, thoroughly cleaned each part, and then re-assembled using the gasketing stuff.

Amazingly when I re-assembled it all and re-timed the valves the engine turned over by hand just as smoothly as it did before I broke it all down. I had

been expecting to have to jiggle about and make fine adjustments in order to get the sweet spot on all the parts that have some adjustment.

Anyway, the engine is much quieter in running ( much less hiss ), and so I set about running it in some more. I hooked up my (slightly) larger air

compressor (12L reciever, doesnt sound larger, but my other compressor is an airbrush  compressor with a 3L tank!! ) and let it run on about 30psi. Due to

the small size of tank, and the fairly thirsty nature of my build of this engine at this time, the compressor was kicking in a little too often for my liking, so I

would run it for about 5 mins and then let the compressor rest for 15-20 mins while I did something else, and then ran the engine in the opposite direction.

I kept this up until I reckon I had about 30-35 mins running time on the engine ( all the while feeding it with a little oil each time I rested the compressor )

It was then running a lot free-er freeer freer ummm  , looser. Even to the point that I can turn the engine over just by gripping the crankshaft (

an oily 5mm steel rod ) with my fingers. Compare that to when I could hardly turn it over gripping the flywheel!!

Now I can run it off my little compressor which has a more accurate pressure gauge, and it will quite happily turn over on 7-8 psi in it's favored direction,

and 12-13psi in the opposite direction.

This one is running at 10-11psi, you can hear that my little airbrush compressor kicks in after a few secs and provides some needed background music to

both clips :lol:

Here's the 1st vid ( available in full HD as well )

<a href="" target="_blank"></a>

And here is the promised 2nd vid, this time a closer view and a slower one, running on 5psi !!!

<a href="" target="_blank"></a>

I just wanted to add a little note to the end of this build log.

I've noticed on madmodder and elsewhere, some folk are working hard on improving their chinese-made machines and ironing out any imperfections in

their lathe and mill, and I am now doing the same thing to my lathe and mill as well.

But dont let that fool any of you who may be wondering about getting one of these into thinking that you have to do a whole load of work on them before

you can make any "fun" projects. I bought both my X2 mini-mill and my C2 mini-lathe from axminster (free postage to northern ireland ) and apart from

cleaning off the red grease that was liberally spread over every concievable surface (and then some more), bolting them to a worktop and then plugging

them in, I have done virtually nothing to the machines themselves. The only thing I did was to get a quick-change toolpost for the lathe and also a ER32

collet set and arbors for lathe and mill, and built a belt-drive for the mill which just made it quieter and smoother running.

My hope was to build a couple of engines and then turn to improving my machines after I was a little more experienced in machining.

These machines have improved a lot in their out-of-the-box state, and I have proved that you can make some fairly precision parts on them without having

made a raft of improvements to them. Yes, I am in no doubt that there are many improvements that can be made and that these will greatly improve the

ability and repeatability and accuracy of the machines, but dont be put off from getting one of them if that is what you can afford, you can make some very

good parts and engines with them, and then you can use them to make parts to improve the machines themselves.

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME


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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #12 on: July 20, 2012, 10:17:12 PM »
Tim, you sure made a meal of it making that one

That is the fastest build of one of these engines that I have ever read, and you are did a great job of it.

It really is amazing that these engines are still being built. It is such a long time since my ramblings were put into text and C-o-C's.

I still have emails from people asking to clarify something in the 'book' and it takes me a while to remember everything.

Well done on getting it to run OK.


Offline lazylathe

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #13 on: July 20, 2012, 11:26:11 PM »
You make it look so easy Tim!!!

A great build thread that i am sure will prompt a few more builds of this fantastic engine.

A new place to hide my swarf!

Offline spuddevans

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Re: My version of Bogstandard's Paddleducks engine build log
« Reply #14 on: July 21, 2012, 08:58:37 AM »
That is the fastest build of one of these engines that I have ever read, and you are did a great job of it.

Well I should have mentioned that this build took about 12 months to accomplish, so not really so quick, I just wanted to add some content to the site and so I spent a couple of hours compiling all the build log posts from Madmodder into one massive page.

I must also sincerely apologise to anyone who does not have a fast internet connection, just go and make a flask of coffee and get a few sticky buns while you wait for all the pics to load.

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME