Scott Flamelicker (Vacuum Engine)

[Bogstandard]

My first real post about making engines on our new site, even though most of you have seen it before.

If I was allowed to have a strong drink to celebrate, I would.

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I gave up making things from castings a fair while ago, purely because the quality had got so bad (and still is amongst some of the well known suppliers).
A  couple of years ago, I took a chance on a company I had never used before for castings, and bought two casting kits, this one and one for a full sized engine called the R & B, from Bruce engineering.

This one will be used to get me back into the swing of things, because no matter what people say, castings are not an easy way of making things, in fact, if you don't make them right, they can turn out to be an absolute eyesore, or it can cost lots of pennies buying new castings if you bugger up the initial ones. A lot of the second hand part built ones are sold by people who have become disillusioned when they thought they would be getting an easy build.

So now onto the way I get things done, others will have different methods, and as I don't like the way the instructions say how to build it, I will be doing it my way for some of the major parts.


So this is what comes in the kit. Everything you need to make the running engine, ball races, springs, even the fasteners, all except for the burner parts. That is because you have a choice of two methods, spirit and wick or butane/propane mix from a refillable gas tank. I will be going down the gas route, purely because in my steam days, I used to make refillable gas tanks, and I have a fully tested one waiting in the wings.

The quality of the castings, IMHO, are very reasonable, no surface blow holes or sags, intimating that something is amiss inside, and one thing I like the most, they haven't been over fettled by some gorilla using an angle grinder. I can take metal off easily enough, but putting it back on is a PITA.
The plans and instructions are well detailed, and I am sure if you follow them, you would end up with a working engine, which when finished, will be about 10" long by something like 6" wide, so not a small engine at all.



When I first bought the castings I had done a little bit of the cleaning up on the flywheel, just a couple of the segments. Now I have new files to fit the die filer, why waste energy.



In about ten minutes, I had the whole lot rough fettled, and not one single aching muscle or sore finger, it did a great job. This part will now be put away, and when the time comes to start turning and boring, a smaller and finer file will be fitted and it will be brought down to finished proportions.



This is the first piece that will get my major attention, the base casting. BTW, this engine is an Imperial build with BA fasteners, and because that are what are supplied, I will be using them.
So away with the metric measuring instruments, and in with the Imperial. Also, because the base is over 6" long, I will be using an 8" dial vernier rather than the 6" digivern.

The first thing that I did was to roughly check things for square and straightness, they were OK, then check for thicknesses and flatness.

By the time I had given it a good going over, I decided that the four top faces of the base bolt hole bosses were going to be my first datum points.




This is the first part that will need cleaning up, the bottom of the base. Once that is done, everything else should fall into place.

I don't like holding directly on the castings because of all the release tapers on them, so the first bit to be made will be a jig plate for it to be bolted to. That will allow me to mount and swing it about to known datums, and so everything will end up nice and square and straight.



If anyone is interested in a little more detail, here is a set of build articles that came from the public domain. I downloaded them and turned it into a PDF to keep it all together.

File name: Scott vacuum engine.pdf File size: 4.52 MB

As you will see. it is not a very difficult an engine to build, all it needs is to keep tolerances under control, as with all flame lickers, and a few specialist bits, like honing the bore and making a gas tank (if you go with gas). The gas tank build isn't shown in these articles, as I am worried someone with not enough experience or testing facilities would have a go and maybe hurt themselves, but the details are shown fully on the plans, or you can buy a commercial one, plus the feed tube and jet.


So I may as well explain things a little. Being from an engineering background, you always try to look ahead a little. Well with this post I am certainly doing that. A couple of hours spent making a few fixtures can save many hours over the build of maybe not an engine this small, but anything a bit larger and more complicated, and you will have trouble progressing very far at all without them, so I am taking the opportunity to save myself a little time, and keep things more accurate than I could ever have hoped for if I was just holding the castings in the vice.

First off, I grabbed a bit of my favourite stuff, 12mm thick ali jig plate. Then I machined it square on all sides, and it ended up about 3/4" over the size of the main base casting.
The parallel sticking up the side (there is another one in the opposite direction on the other side) is to help keep things from flopping about and vibrating while being machined, because it is sticking up so far above the vice jaws.
Almost any material can be used for the holding plate, as long as it is sturdy and accurate enough to do the job.



A cutout was put into one side, you will see why a little later.
You will also notice the odd hole here and there. When this stuff comes out of a factory as scrap, it has invariably already been used as a jig plate, you just gotta take what you can get.




So this is the basic holding plate made, all nice and square and flat.
I suppose you can guess what fits into the cutaway now.


So the next job is to find out where to drill the holes in the plate, and this is one of the very few times I will hold a basic casting as large as this in a vice. All because the are usually no straight sides on the casting, so making holding in a vice very unstable. I could have clamped it down to the bed, but that would have meant me removing either my vice or RT, and because I am only doing very light machining on it, I take the chance.




I have already decided that the top faces of these bolt hole bosses are going to be my first start datum points, so what I am doing, by eye, is finding the centre of each of the four bosses and spotting it with a ball nosed cutter.




This shot shows just how 'bent' the casting is, look at what should be a straight face on the side left hand top edge, and the same on the right hand bottom edge. Now you can see why castings can't be treated like normal bits of metal. They can be bent like a bananas at times, and what you should be trying to do, is not to take all the bends out, but get them looking a little more presentable.




So now having the four 'holes' spotted, I can measure up and come to a 'mean' position for the holes. By drilling smaller holes in the holding plate, than the larger ones in the base, it will give a bit of 'fiddle factor later on.




The small holes were precision drilled in the plate, and the larger hold down bolt holes were drilled by eye. On the underside of the casting, where it won't be seen, I put recesses for the screws that will be used to hold it down for initial machining.
Also I made four 1" long upstands that were threaded all the way thru. The upstands were first screwed to the holding plate.



The plate, tapped down onto parallels, had the four upstands all skimmed on the top faces to ensure they were all the same length




The cast base was then screwed downwards onto the four upstands, the screws went into the recesses while the sticky up bit of the casting went thru the cutout in the holding plate.




The whole lot was now gently tapped down onto parallels and everything given a final tighten up.
Then the gnasher came along and took off the hard skin, and the highs and hollows on the base. It took a cut of 0.020" to clean it all up




The fine sweeper then came on the scene, and with a 0.003" cut, took out all the rough machining marks and left behind a nice smooth, perfectly level surface.



I now have a main datum base I can actually work with.




Everything was cleaned down, the casting taken off and the upstands removed. The casting was then bolted, using all the same drilled holes, onto the holding plate.




Once it is mounted back onto the mill, by using a DTI, I can swipe down all the edges and standing up parts, and by gently tapping, I can get the casting into it's optimum position to have any machining done on it.

This will ensure, by using the holding plate as a reference, I will be able to locate all holes and ensure that they are all drilled in the right places and all parallel to each other. Almost an impossible job if you were trying to hold the raw castings by themselves.

This plate will also be reused for the other parts that need machining, so it will not be wasted.

I now hope this goes some way to explaining what the daft old bugger is up to.


John

[lazylathe]

Nice one John!!!

A few more posts and i will be all caught up!
Your builds always teach me something new, which is what i really enjoy!

Andrew

[Bogstandard]

I'm glad you like the posts Andrew, here is another one for you to pick through for tips.

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Most times, small casting kits just come with the instructions to file a flat surface somewhere on the casting and work from that. To me that is not acceptable, and why such a lot of beginners fall foul when doing their first casting builds. Usually ending up by throwing it under the bench when everything goes pear shaped.
Unfortunately, castings are all sorts of shapes, purely because the patterns have to release from the mould, and a flat face just won't cut it, so they have shallow tapers everywhere, nothing that you can get a true measurement off.

By me choosing this one major face to get perfect, now very easily, I can, if needed, get a few more faces square to it. Whereas before, I would be stabbing in the dark just where to drill holes and whether they are going to be parallel to each other.

As I said at the start, this build is a sort of prep for when I get onto the real deal, getting me used to working with castings again, because no matter what, if you do go in blind, you will almost certainly end up with some sort of error or bodge on the finished item.

I will say one thing though, working from drawings using bar stock materials is infinitely easier than using castings. It just isn't for everyone.


Now is the time to start to get the datums on the main bedplate sorted.


You will remember from last time, the bedplate was screwed down to the jig plate, but not yet squared up.
Mounted into the vice, as usual, bedded down onto a couple of parallels and the DTI was then brought into play.

I went all over the castings, looking for areas that matched for squareness, and by taking a few mean figures, I gently persuaded the plate to go into a position where, when machined, datum faces would be produced that would make sure that all the holes will be in the correct position.




The front and two side faces were cleaned up, the rear one can be done anytime as that will not be used in any marking up.

Some people will say I am removing too much of the casting features. All I can say is that I prefer to have an engine that is square, accurately made and not having to bodge things to get it running. If needed, the rough finish can be put back on once everything has been machined.




With the three sides cleaned up and totally square to everything else, it is time to get some measuring done.




The plate was blued up, and by using the two central upstands as datums, I found the centre point between them, and because I had the sides square, by using engineers squares, I could then mark up the centre line and an area of the plate to be machined to become the main vertical datum.




You can see here on my sketch and workings out the datum to be produced, and the exact positions vertically to the critical hole positions required.

Now the bedplate can be held accurately, it will be an easy job to get these holes drilled.

Don't worry about the vertical measurements being shown going to the wrong positions, they are in fact the hole centre heights from the datum face.



Back onto the mill again, and getting to grips with making the main datum face for the whole engine. What is required is to clean the surface off to remove all hi/lo spots. I found that taking a cut of 0.005" was enough to achieve the goal.




Once that flat area was completed, I jumped over to the cast in recess, and because it was full of lumps and bumps, I cleaned the whole lot up to make it look more presentable.




This is the finished result, all ready to have the bearing holes drilled and bored in the three uprights.




Now we are getting somewhere.


My DRO had remembered where the centre line was from yesterday, so it was just a matter of getting a zero datum from the end face.




Once that was done, it was an easy matter of spotting and drilling the three required holes. Horizontal work on the base is now done, except for drilling the oil cup holes, which can be done at any time, using the datums I have already created, even after it is taken off the holding plate.




Now this is where the plate comes into it's own. Swung to a vertical position, and clamped against the vice fixed jaw with a 3,2,1 block. This is plenty rigid enough for the jobs I am now about to do.




By having the 3,2,1 block hanging over a little, I can easily find the Y axis setting for the flat face I machined up last time.




And the machined end of the casting gave me the X axis position.




The X & Y were set to zero




And the figures that I had worked out were fed into the table, the table locks were then tightened up.




This put my quill spot on over the position that is shown on the plans. A hole was spotted and drilled.




A long series centre drill was then used to spot thru onto the second part of the casting.




The hole was then drilled using a long series drill.




Both holes in line. I don't have a machine reamer that will reach both holes, so this will be done with a hand reamer later.




I now moved to the second set of coordinates I had, then spotted and step drilled up to 12mm diameter.




The boring bar then came into action, and the hole was opened out to 13mm, the size of bearing supplied for the flywheel shaft support.




A nice slip fit for the bearing. Eventually, a pair of them will be Loctited into this hole.




So that is the baseplate basically finished, except for a little fine fettling and tapping one of the holes that I drilled earlier, and of course the three oil cup holes. I have already hand reamed the two cross holes.




I hope you can now see why I used the jig plate. Fairly easily, not only did I get the surfaces, top and bottom, level and parallel to each other, but also all the holes in the correct relationship and again parallel to not only each other, but to the base datums as well. So it was definitely worth doing on this build.

So the next step of the journey is to get that big lump of gunmetal into shape. I think this is one of those stages where I will have to hold the rough casting in the vice to get my first flat face, the bottom. Then take it from there.


John

[lazylathe]

Ahhh Haaa!! You see i told you i would pick up some tips!

I have a set of castings for a Coles Black Night Steam Engine that nothing is parallel or straight on them.
Now i have a tip on how to get them close and make some datum points for reference!

Andrew

[Dean W]

I remember this one from another time, John.  You picked a good one to help get things going in the Projects section.
Glad to see it again, if only to "re-remember" things that seem to dribble out of my head over time. 

[Bogstandard]

Yep Dean, this post has been moved from place to place, and now, hopefully it has now found a permanent home where, after these build notes, up to now, are displayed, the engine can actually be finished off. That is of course if I am able to do it. After a layoff of almost a year due to personal issues, it will be difficult for me to get the old sinews moving again.

Andrew,

That is why we all post on here, to me, not for the glory, but to help people like yourself who are following.

Why struggle, trying to figure something out, when someone has already done all the hard work for you.

I still read almost every build post avidly, there are tips I can pick up as well.

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Even though it looked OK from a distance, when I got up close and personal with this casting, I was a little disappointed, as will be seen. I spent nearly an hour, trying to make a decision how I was going to machine it back to how I wanted it. At least one specific face had to be machined perfectly square to the foot, and then bored for the cylinder.

As you can see by the fettling marks, this side has an outwards bulge, and when handled, is more pronounced than shown on this photo.




As can be seen from this shot viewed from the side, the shape is more like a leaning parallelogram rather than an oblong.



When viewed from the top, you can also see that it tapers from one side to the other.
Luckily, although in parts, the casting is under nominal size, there is enough meat on it to get it all square.




I decided the best place to start was the already fettled base, which was reasonably flat, so it was gripped in the vice with the base set level to the table.
I just needed to make sure the cutting forces were kept as low as possible.




With a bit of extra support from the backstop, I used my flycutter, cutting in one direction only (towards the backstop) and with only a 0.005" cut, the base was cleaned up after a couple of passes.




This shot shows just how much inwards lean at the top there is on the sides. The next cut has to be getting the side face that requires boring square to the base.




The casting was set up again in the vice with the base sticking out.
By using a 3 2 1 block and a nut and bolt just slightly smaller than the holes in the block, I jacked the base end up so that the base was perfectly square to the table. Hopefully it will remain in that square position while the face is machined. The block and jacking screw were left in position to help support the part.




I tried to skim this unfettled face with my flycutter, but the skin was a little hard and didn't really want to cut. You can see by the machining marks just how far out this face is.




So I resorted to one of my favourites, a 16mm razor sharp cutter. This went thru it like it was butter.




This slightly fuzzy shot shows just how bent the face was, and this isn't down to full cleanup depth yet.




After going down to just over 60 thou, I had the face cleaned up, and yes, it was perfectly square to the base.
Now I have these two faces, everything else will be an easy job. Even though the angles are slightly out to each other on the two angled faces, as of yet, I have decided they won't be machined, and left as cast.




To me, it is looking better already.





Last time I had got the two faces square to each other and nice and flat. This time is getting the third face square or parallel to the other two.
This is the standard set up technique, one good face down and tapped onto a pair of parallels, with the other square and flat face against the fixed chuck jaw. A piece of soft material, in this case ali, is placed between the moving jaw and the fourth rough side. Doing that puts all the pressure onto one small point and takes up some of the irregularities on the job. You don't want to go putting on heavy cuts while in this sort of setup, in fact, I changed my normal cutting direction, from X to the Y axis.




The top surface was soon cleaned up.




I need the big offset hole in the top cleaning up for a feature I will be adding, so the boring head was roughly centred and set to work.




This is as far as I want to go with this piece at this time. It still need a few small holes drilling, and boring for the cylinder sleeve. But I want to wait until that is finished first, as the boring is a more controllable exercise than bringing the sleeve down to size.



John

[Bogstandard]

Some of you will recognise this bit of brass left over from the swing up threading post, but the threaded bit on the end is just perfect for what I want.
I just took the thread down until it was cleaned off.




A quick change of tool and I had a spigot of the right size formed on the end.



A large profile tool soon had a nice radius formed.




Drill out the end a bit.




Then opened up to the required size. All this by the way is being done by eye, except for the spigot on the end size.




The bit I want was parted off.




Now comes the experience bit. All my working life, and a bit before, I have been hand shaping parts on the lathe, using a few basic tools. The basic name for it is called graving, a basic watchmakers technique which uses shaped hand held cutting tools similar to what a wood turner uses, but much smaller. I am not using those this time, just files and a sanding block, and I use it just to give me something unique that is very quick to do.

It is not difficult at all, and a lot of lathework started off just this way, but it can be dangerous if you don't know how to hold the tools correctly, and also, you are working with your fingers very close to a fast spinning chuck, and as you all know, machines have no feelings, and they will chop you up just as easily as they chop up metal and other materials. So unless you are VERY safety conscious and scared to death of your machines because you know what they can do to you, don't even try it. I am only showing the basics here, and even though it can be dangerous, it is a perfectly recognised way of shaping items in the lathe.

First off, the part was remounted back into the self centring four jaw chuck with the bit I want to shape up to the outside of the jaws. Using hand and eye coordination, plus a boring bar, I roughly profiled the inside of the part to match the outside bit which had been machined.




Using just a few files and a sponge emery block, I blended all the rough cuts into one smooth flowing rounded shape, getting rid of all the maching marks at the same time.
A sheet of white paper put onto the background helps in seeing that everything is blended together, having just nice rounded curves with no flat spots.




A quick dose of Mrs Buff had a nice basic shine added to the part. Just before final assembly, it will be given a final deep lustre polish.




As you have most probably already guessed, this is a nicely shaped funnel for the water jacket,  instead of the horrible gaping hole that is shown on the plans.




Total time, just over an hour. Time well spent as far as I am concerned.


I don't know if I put people off by my comments about hand graving and the safety issues, but in all honesty, if you care to take the time and train yourself to work very closely to the chuck, it can be a very rewarding experience.

I have forgotten the amount of boiler funnel caps I have made for people, but something like that can really put the finishing touches to a steam plant or a distinguishing part for an engine can really set it out from the ordinary.

As I have shown before, where I turned up shaped steel handles, they are not available commercially, but if you can have a go yourself, almost any turned shape is possible. From little hand turned finials in place of nuts as on my mine engine, to a spinner shaped cone to fit my small turbine and elbow engines. All done in a matter of minutes, and totally unique.

For my graver rest, when I use a graver, I just mount a bar in my toolpost and bring it close up to the job, so no special lathe fitments are required. BTW, great gravers can be made out of worn out files, just grind up the shape you require on the end and leave most of the teeth on there, they give a good non slip surface to hold onto, but make sure you leave the original handle in place.


The next bit of natural progression for me was to get the cylinder made, and a nice big lump of cast iron was supplied. In fact, enough to make two, if I don't get the first one right.


It was mounted up in the chuck, the free end gently centre drilled and a rotating centre was used as support. Then it was just a matter of cutting it down to size.




By taking things steady and slowly, the outer surfaces were brought down to exact sizes and lengths.
The machined up bit was then held in the chuck while the rest was parted off.
But due to an unfortunate accident, where I couldn't take the weight of the piece that was being parted off correctly, it trapped my favourite parting off tool and snapped the end off. Back onto fleabay to find a replacement. You win some, you lose some. I still have the left hand version of the same tool, so I will be OK until I find another.

Normally for taking off such a large lump I would have used my power hacksaw, so it was my own fault for trying to do things too fast.



As you can see by comparing it to the digivern, it is a rather large cylinder.
I checked to see if I had enough length on my boring bar to get the bore done, and it looks like I will get away with it, if I take it steady.

The 4" long lump at the side was the piece that trapped my parting tool and broke it, all because I couldn't support the weight.




Away we go, my way of boring a cylinder.


First off, I am using a four jaw self centring chuck, not a 4 jaw independent. I find they are a little more accurate than a normal 3 jaw.

One of the first things you will notice are the brass shim protectors, you could use cut up drinks cans instead. Cast iron, although fairly hard to penetrate can have the surface bruised very easily by unprotected jaws, these are used to help prevent that. There is no need to go to white knuckle tightening up, they grip rather well without going that far.
The flange was faced to correct thickness.




By using different sized drills, I gradually removed most of the material to come out of the bore.
I left 3/16" to bore out. You can go much closer than that, but I like to use the run up to final size to gauge how the bar is cutting. Writing down the cut put on and seeing if it matches with the amount taken off.




The boring tool was set up in it's holder. Making sure that it will go all the way thru the part. I also set up the saddle stop so that it works just after the tool has gone all the way thru.
This is really sticking out a bit more than normal, but this is a 16mm diameter tool and I have found that they are more rigid than a normal steel one of the same size, so if normal cutting pressures are kept low (no big depth cuts) then everything will be fine.




So the sleeve was remounted into the chuck, but using a slightly different method.
The flange goes fully up to the jaws, to stop the sleeve being pushed inside the chuck as I put a new cut on. Secondly, the protectors are still used, but the jaws are only tightened just enough to stop the part spinning in the chuck.
If you tighten up too much, the outside walls will be pressed inwards and when the boring bar takes it's cut, it will be off the metal that has been pushed inwards and you will find that when the chuck pressure is taken off, you will end up with a triangular(if using a 3 jaw) or square (if using a 4jaw) shaped hole, not perfectly round. I hope you understood that.
If possible, I always try to bore thin wall items with the bored part being outside of the chuck jaws.

Anyway, back to cutting out this hole. I rough cut out at 0.025" cuts for the first few, until I got within say 15 thou of required hole size. Then remove the material until it leaves about 0,002" to be removed. The closer you get to size, the finer and slower the feed you use.
I do the final cut, measure that it is either spot on or very close to size, then using a very fine feed, take another half dozen cuts with no more cut on at all, just using the same setting as the final one used to get down to size. This is to take off any material that wasn't cut because of the tool flexing as it went down the bore.
All this lot took well over an hour, but hey, the job isn't going to get up and run away, so time shouldn't enter into the equation, other than the longer you take on it, usually the better results you get.




The bore, measured at either end was exactly the same, one thou oversize, so no tapered bore. I suppose I should have used my deep bore gauge as I was doing the job, but I couldn't be bothered to unpack my instrument cupboard to get to it.
The surface finish was smooth as silk. I love working with cast iron for that very reason, you can get fabulous smooth finishes on it.



The last pic shows the sleeve sitting on a bar of metal. Cast iron again, and that will end up as the piston. A job for next time.

Actually, the instructions that came with the engine suggests honing the bore at this time. Personally I think that is the wrong way to go on an engine such as this, so after the piston is brought down to size, it will be lapped in with the cylinder bore, that will give an even smoother and less friction of fit than honing could achieve.

John

[Bogstandard]

I will most probably spend more time on getting a good finish between the bore and piston than I have spent making the two parts.

To me, they are the most important part of an engine, and getting it right first time will eliminate any queries about them when it comes to get the engine running, if there are any problems.


Because there was so little spare length to hold the billet in the chuck (3/16") to complete the piston by normal methods, I am using a feature that is normally put in last to actually help me make the part. When you see the finished article, you will see why I went down this route.
First off, I did a fine face off on the end, then drilled and tapped a 3/16" x 40 tpi thread in it (normally the last bit to do). This is going to be the main datum for the whole machining exercise.




I now went over the whole billet, rough skinning it down to within about 0.050" of finished size all over.

This is removing metal from the other end of the billet.



The O.D. was taken down in two stages.



The final part was to remove the bulk from the inside.



So this is what I ended up with. I now need to be able to hold this fairly rigid while I bring everything down to size.
Time to make a mandrel.




Using a piece of bar end, I turned a spigot sticking out on the end and then faced the end off smooth. The spigot was then threaded 3/16" x 40 tpi.



The part was then screwed on tight onto the spigot screw and faced end.




I need to get the heaviest of the machining done first, as the screw will be gradually shortened to a couple of threads by the time the centre is bored out.

First off, the piston was brought down to exact length.




Followed very gently by removing all the inside of the piston by boring. You can just see at the bottom of the hole where the screw has been shortened by the boring exercise.




The OD of the piston was then brought down until it just fitted inside the bore, just a nice push fit.




You can now see how much metal was removed, I suppose because the piston needs to be very light just so that friction and reciprocating forces don't get too high.

If I had tried to hold this with a normal chuck, I would imagine it would have collapsed.



My mic said I had 0.0006" clearance (about 0.015mm). That will be spot on for when I start to lap the piston to bore. Hopefully I will end up with about 1 thou clearance (0.025mm).




You can also see that the bar end will act as a perfect piston holding handle for doing the lapping with.


Now the dirty work begins with the lapping.

Almost everything after that is straightforwards machining and sticking or silver soldering together.


With regards to showing lapping etc. The US lads have a definite advantage over me in that department. They have retail access to very cheap soft laps, whereas in the UK, although most probably available, they will be neither as cheap or accessible as the US ones are.

So I personally have to use old and trusted methods for achieving what is required.

I will just explain something that I haven't shown.

When the unlapped piston was pushed thru the bore, I noticed that about 2/3rds the way up from the end (opposite to the flange end of the cylinder) I noticed there was a slight binding up between the two parts. If I had had not been so lazy and used my bore gauge from the start, rather than using an internal mic at each end, I would have picked this up and taken a few more non feed cuts when I was boring the cylinder. As it was, I used my bore hone to straighten things out. There was most probably only about a tenth to be removed, and it only took a couple of minutes to hone it out.

All operations were done on the slowest setting my lathe will go, 65 RPM.

After that, it was just a matter of starting out with a bit of diamond paste gently spread onto the surface of the piston. I wouldn't recommend using diamond if it was a non ferrous bore or piston, as it tends to permanently embed itself into the soft metal surface, so if it isn't all completely removed, it will carry on wearing away the bore as the engine is running. After a good wash down with thinners, I used a commercial chrome polish, cleaned down again, then finished off with rouge paste.
These operations took just over an hour, gently rotating the sleeve up and down the over the piston in a sort of figure of eight movement until things start slackening off and getting easier with each different compound. I recharged each compound about 3 or 4 times, when it started to get filthy loaded with cast iron sludge. You have to make sure that the whole inner surface of the bore is lapped to the outer surface of the piston.
In the beginning, the sleeve had to be held fairly tight to stop it rotating with the piston, but as things went on, it got easier to hold. The final lap was actually done with just one finger pressure moving the sleeve up and down.




I tried to get a flash shot showing the semi chrome finish on both the bore and piston, but failed miserably. Because I am scared of boogie men, I won't go out to the shop in the dark to take another picture.
Anyway, another take my word for it, they were s-m-o-o-t-h as silk.

In fact, just by gently sucking and blowing on the flanged end of the cylinder, the piston went up and down in the bore.



I have taken a shot of the bits and bobs that I used for the exercise, and I will try to explain how the hone works.

On the left is my commercial cylinder hone, designed for things like brake cylinders and small i/c bores. I paid less than 20 squid for this off the net, from a motor factors. If you buy one from a model engineering supplier, they will cost you double that, for exactly the same thing (or even less contents).

This one will work with bores from around 3/4" up to about 3.5". You can buy extra stones, both harder and softer grades in different lengths, to cater for different materials and depth of bore. I have found the ones supplied have done a great job on all the different bores I have honed.

The way they work is that when the stones are fed into the bore, they lie flat against the inner surface, and by gently rotating in the bore, and moving it in and out, as I did my lapping, it will gradually make the bore perfectly parallel and round. In use, you keep it well lubricated, I use my general purpose hydraulic oil that I use on my machine for the gearboxes and local lubrication, and by adjusting a thumb screw at the back of the spring, you can make the stones cut harder or softer. The closer you get to perfect, the softer you have the setting.

These hones are not really for getting a very smooth bore, but they will do if adjusted correctly, as I said, they are used for getting things straightened out. You will find that after use, if you have followed the movement regime I mentioned earlier, there are minute scratches in the bore face. As the engine is running in, oil will get trapped in these tiny scratches and help prevent the piston seizing in the bore as the two bed in together over time. Eventually the scratches will be worn away and you will end up with highly polished bore and piston.

From certain model engineer suppliers, you can buy casting kits that when made up will do the same thing for the outside of the pistons, they are called external hones.

The lapping I have done does away with this engine running in period, and the engine should be able to get up to full speed from the start.

On the right hand side of the pic are the three compounds I used for lapping. The green stuff at the back is my own diamond lapping paste that I made up a few years ago, and it is used to get most of the sleeve to piston undulations removed. Next one down is a commercial chrome polish. This is for getting things started to be really smooth, then followed by the jewellers rouge which imparts a nice polish to both surfaces.

People use all sorts of different compounds for lapping, these are just the basic ones I use. If I was doing a non ferrous bore or piston, I would actually use an aluminium oxide grinding paste (the stuff used for grinding in valves on a car) instead of the diamond paste. The ali oxide actually breaks down into a harmless sludge during the lapping process, so is easily washed off, and causing no further wear to the parts.




So that is the cylinder bore and piston finished, except for drilling a few mounting holes. That means I can get back onto making things.

So you have to imagine what I look like now, hands filthy, embedded CI dust in the pores, the front of my white t-shirt covered in the same stuff, and a ring of dirty oil around my lips, from sucking the piston in and out



I need to find where to bore the hole so that when the sleeve is fitted, not only is it parallel to the base but also the correct height from it. The conrod has a fairly wide sweep up and down, and if those two are not correct, within reason, the conrod will catch the edge of the cylinder.
So using an old fitters trick, I filled the cast hole up with a bit of sheet lead tapped into position so that it grabs the inside of the hole. There are many other methods that can be used, bits of wood etc, but I find that this way suits me.




By using a few hand tools, and a copy of John Stevensons precision oddleg scribing calipers, I got the centre hole spotted to within a couple of thou. When working with castings such as this, that is perfectly good enough.
It took the opportunity to mark up where the faced area needs to be cut to.




Using my coaxial thingybob I soon had the centre found and the table zeroed up and locked.




I was soon boring thru both the top and bottom faces.
I did find out the the boring head actually removes double the amount that is set, the normal thing on a lathe, but no problems keeping things accurate, it is marked up in half thous.




It was soon up to a position where the sleeve could be gently pushed thru both top and bottom faces. I should have no trouble sealing the sleeve into the hopper.
There was a problem with the boring head, I had made the key handle much too small, and it hurt my fingers as I took the facing cuts. Because of this, I actually forgot to take any pics of the facing exercise.
I will soon be able to knock up a more comfortable key, and maybe another time I can show it facing off.




But it actually did a superb job, totally square to the bore, but I did have to go to 0.025" (0.6mm) deep to clean off the casting face so that the sleeve flange sat flat all the way around.




The two parts pushed together. I'm very happy with the results.




I am now in the process of recentring everything up, because if I now make the cylinder head and stick it onto these two bits, I can drill all the holding bolts at the same time rather than having to spot thru from a previously drilled cylinder head, and maybe make a mistake.




John

[Stuart]

Nice to see your builds John

I always find a new wrinkle to a machine problem that will come up in the future


I like many other I look forwards to many more


Stuart

[lazylathe]

I think i am up to date now John!
More great info to be gleaned from that post.

Looking forward to the upcoming ones too!

Andrew

[Bogstandard]

I had forgotten that the head had to be made before getting everything set up in the mill again, so here are the bits again. I need to take just over 1/4" off the bar of cast iron and that will then go into stock, a nice little freebie supplied with the kit.




The bar was again mounted up into my 4 jaw self centring and the head was turned to dimensions on the end of it.

I also drilled a hole in the centre, just deep enough for the parting tool to hit. That helps a lot with parting off, especially with these large diameters, the tool doesn't have to reach all the way to the middle, which is the area that cutting failure usually starts to cause problems.




It parted off just fine.




It fitted into the sleeve nice and snug.




I had a choice now. The instructions said that the end face of the cylinder head had to be as flat and as smooth as possible. If it wasn't that way, and it was left roughish, it would act like a file on the graphite block that is used as the sliding flame hole cover, and it would last no time at all.
I could either get that flat and smooth face by ten minutes on the surface grinder, or an hour with a lapping plate. I thought the grinder would be the better choice for me.

So not only was it flatted off, but it was taken down to the correct thickness, which saved another setup and facing job on the lathe.




Smooth and flat, just the job.




It was at this point I started to do a bit of forwards planning. The head required six mounting holes drilling into it, plus the flame hole needed to be machined. Once that was done, the holes were then to be transferred onto both the sleeve and the water hopper (keeping everything in the correct orientation). IMHO, a cock up waiting to happen.
So I first superglued the sleeve into the hopper.




NOW it was time to get it set up in the mill.

BTW, if you do have the opportunity to obtain one of these coaxial jobbies, I can thoroughly recommend them. This one is spot on, and has saved me hours on set up times. But they do take up a bit of throat space, so no use on the smaller mill or lathe.




The newly made head was then superglued into the sleeve, and a weight added for ten minutes, giving it enough time to make the joint.
I use superglue a lot for little jobs such as this, where there aren't heavy machining forces involved.



Using the coordinate feature of my DRO, I spotted then drilled down into the hopper with the correct size for tapping.
Then a quickie calculation and set up, I followed down with an end mill of the right clearance size for the fastener exactly to the depth of the head and sleeve flange.

The plans call for 5BA bolts, but I actually prefer something like this to be held with studs and nuts, so I am using 3mm studs, with washers and nuts, to give a nice neat fixing.




By doing it the way I did above, I could now reach down with a tap and finish off the threads in the water hopper by hand.




That then allowed me to use some screws to hold everything together, so that it could resist the cutting forces to come. The superglue was now redundant




The flame slot was first milled out with a one size smaller cutter, the correct size one was then used. You will get a more accurate hole and better finish by doing it this way.




Job done.
Four operations combined into one, guaranteeing that everything is in the correct position.




A few seconds heat from a blowtorch soon broke the grip of the superglue, and when cooled down, it can be peeled off the surfaces with a fingernail.




I have a bit of a compulsion about flywheels. Usually they are the most noticeable item on an engine, and if they run out even a tiny amount on the rim and sides, they can spoil the look of an engine completely. So I will go to great lengths to achieve, if possible, a flywheel with no runout at all on the rim area. As far as I am concerned the spokes and hub, even though a little out don't detract from anything if the rim is spot on.

Unlike a bulky cast iron flywheel, where the rough casting adds character, my personal view with this one is that the more it is cleaned up, the better it will look. It has a very elegant shape, especially the tapered in rim sides and the eliptical cross section tapered spokes. Some might agree, lots won't. But to me a casting is just a means to an end, a finished correctly shaped component, if it needs every surface machining, then it gets it, if it doesn't, then the cast finish is left as is.

The casting for this flywheel, on first inspection looked fairly good, just loads of flash around the spokes to clean up. But on closer inpection, there was a fair amount of mismatch between the two halves as they were cast, as you can see on the rim mounted in the chuck.

So the first thing I did was to get it onto my RT and clean up the inner hub area, for somewhere for my chuck to hold onto with some semblance of precision.




I needed to use a smaller range of chucks for this job, so my lathe was converted over to a Myford nose, and because there were 8 spokes, I used my small 4 jaw self centring chuck.

Using a nudger, the rim edge was brought to run true.




I soon had the outer rim, the rim face, hub and centre hole all finished at the same settings, so no matter what, this side of the wheel will look spot on. It was then flipped over and pushed backed with the machined rim edge right on the jaw faces. The second rim edge and hub was machined up. I now had a flywheel with the major edges running perfectly true.
After this stage, the flywheel was put back on the RT to have the inner rims that were machined before, gently trimmed to run perfect with the outer rim.




The flywheel again was mounted back onto the lathe chuck and the angle for the funny shaped sides found, 8?. Once that was done, those areas were cleaned up by using the topslide set over to do the cuts.

So this is the almost finished flywheel, just requiring a little bit of filework to blend the spokes into the rim and get the spokes straightened up down their tapers.

Not one single bit of wobble detected.




It is such a shame that most of it will be covered in paint.



The flywheel will actually be having the whole rim area showing with just the spokes, inner rim and hub painted. It has started to be blinged up with a few detail features, so until the first firing up, it won't be shown as it is put away for protection, while I am still doing rough work on the engine.

Talking about doing a bit of rough work, I have now just completed the main crank and valve operating cam.


The blanks were made up to the drawing dimensions, and using a few basic marking out tools, what needed to be trimmed off was drawn onto them. Nothing too special, near enough will be good enough except for fixed datum points, centre hole in relation to crank throw and operating angle of cam.




To cut the cam flanks, I just placed a parallel along the vice jaw top and eyeballed the drawn line to be in line with the top of the para.




It was then cut away until the cutter just touched on the central boss.




The same was then done with the other flank line. It was remeasured and found to be spot on the required 120 degs. separation.




Next came the crank disc to have a bit of hacking done to it.

Because I will be swinging a fairly large cutter about, cutting to full depth of the flange, I put a washer on top of each jaw as spacers, to stop the cutter hitting my hardened chuck jaws.




With the part being tapped down onto the washers and being held in the jaws on the back boss, the RT was centred up on the crank spindle hole by putting a 6mm spotting drill in the quill and moving the RT about until the drill centred perfectly in the hole.

Next I moved the RT 1" to the left (crank throw dimension) and by turning the RT, I got the spot drill exactly over the centre line of the crank disc. The 5/32"(4mm) tapping hole was then drilled. Crank throw sorted.

The RT was then locked up so that it couldn't be rotated.




Next came cutting out the recesses using a 3/4" slot drill.

By using the X & Y traverses, the marked areas were cut out using shallow cuts until they split the marked lines.




The first one done, the second soon followed suit.




A little bit of filework in the bench vice had everything trimmed down to the lines, followed by a quickie clean up.

Except for drilling their grub screw holes, job done.




Now I can start on the operating rods, made from brass. Rather than following patterns and plans religiously, as long as the holes are in the right places, and nothing fouls, I should be able to use a little artistic license.

John

[Bogstandard]

Soon after starting this build, I stated that I would be looking to put my own stamp on this engine, just to make it look a little different from the ones that have gone before that have been built to what is shown on the plans.
After getting the big bits out of the way, where very little could be changed, I am now into 'almost anything goes' territory, and I will be looking to make a few changes.

Have a look at this con rod, exciting ain't it, not.

I have laid out the metal and bearing just to show what the finished item will look like, I am sure a little redesign will help some.




I won't be able to do anything with the rod that goes into the cylinder, as it will be tight as is.
But the bit on the outside should be able to be given a makeover, so I measured up to see what I had to play with.




The plans are nowhere near to scale, so it might look a little funny when I place parts against it. Also at this time I am totally disregarding balancing of parts for changes I will make, if it needs doing, I will do it all at the end.

I have decided to go with a two part build, the original bits that goes into the cylinder will basically stay the same, the bits outside are now mine.
I will make the two parts, then fix them together, then drill the critical dimension for giving the correct length.
I made a rough pencil sketch on the plans of what I want it to look like.




Again, just using a few marking out tools, I transferred my idea onto the metal.




No special machining needed, just the para on top of the jaws trick to line things up, then cut to split the line.




That was done in a matter of minutes.




The curvy bits at the back got the same treatment, cut until it reaches the line.




As you can see, just a few easy cuts and the complicated looking part is taking shape.
I also drilled a few holes to remove metal and allow access for my hand files. The part was then put into the vice and rough shaped. This is too small a job to break out the die filer, things were easily done by hand.




The two rough parts were then joined together. The ali blocks under and the weights on top were my attempt to keep the two parts flat and in line with each other. It worked.
The joint was silver soldered using my method of fluxing the joints, placing a pallion of silver solder sheet on top of the joint and heating from underneath.




The solder flowed right thru the joint and gave a permanent strong joint.




After a good clean up, the large hole was picked up using a transfer punch in the drill chuck. Once I had that zero point, I just fed along and drilled the other critical hole.




I milled the conrod to thickness in the parts required then set about putting in the half round flutes.




A little more shaping up and it is ready to be put away for final shaping and polishing at a later date.




There are all sorts of rods and linkages now that will get the same sort of treatment. No plain flat bars for me any more.

A few more rods to do. I won't be showing them all as it is a waste of good space, but I will be showing a few things I did to get them made.


These are the rods that need making, and again a little bland to look at.
There is one at 1/8" thick, that is the operating rod from the cam, two from the cross shaft at 1/16" thick and two going up to the graphite block, again 1/16".
The two offs are actually handed pairs, but can be made up as a pair, then the handing put on afterwards. So to make sure they match, I will join them together, machine and shape them as one, then split them apart.




The first job needed is to solder the two 1/16" plates together.
This is my soft solder joining kit. The small G clamps are not used unless the two plates start to wander apart.
The first job is to coat each face with flux, then by hitting the soft plumbers solder between a clean hammer and a hard place it is got to about 0.005" thick. Using scissors, little pallion strips are cut off the flattened solder end and placed along one of the fluxed faces.
The other plate is placed on top, flux face to the solder and the whole lot gently heated until the solder flowed and then allowed to cool down naturally, do not quench, as it will suck water into the joint and be liable to fail, that goes for all soft soldering jobs.




Soft solder is fairly fluid, even when set, so if the plates are slightly out of line, I put them  into the vice edge on and realign them, followed by flat faces and then a good squeeze. These were fairly close, so they aligned really nicely. If they are way out, they need to be reheated and got more into line, that is when I would use the G clamps, while the solder is still hot and liquid. I find it stays that way for quite a while, as the main metal cools down.




A working measurement was required to make the thicker plate, so I needed to get it so that I could measure between two centres at different heights. With a little bit of thinking, the figure was obtained. The edge of the small mag stand was set on centre of the lower one, the small square onto the upper one, and the ruler taking the measurement. 1/32" is plenty close enough for this piece.




The bar that had been soldered up was cut into the two required lengths, then by drilling on the mill I got all centres thru with a 1/16" drill.
After bluing up, my rough sketches were laid out onto the plates. All the holes were then opened up to 1/8".




The next job was to make up a pair of filing buttons. These were made from a piece of 1/4" silver steel (drill rod), drilled down the centre with a 1/8" drill then parted off at about 1/8" thick. Then they were heated up to orangy red for about 30 seconds and then dropped into a tub of cold water. They came out glass hard, just what is needed, and no need to clean them up. A short 1/8" spindle was made up out of a piece of unhardened silver steel.





This is how they work. One either side of the bit to be filed to shape and then the spindle is rested on top of the vice jaws as the vice is tightened up, trapping the part between the two buttons.

You then file downwards until you can file no more, the buttons are so hard, if you carry on, your file will soon be buggered. Just file around the buttons until the ends become very nicely radiused, taking on the shape of the buttons.




It only took a couple of minutes to get these done, then it was onto the mill to split the drawn lines, as shown in previous posts, then a little hand filing to blend things together.

If you notice, there is only one filing button here, the other shattered when I tightened up the vice on one of the other plates, so I had to rely on my ability to keep the file level while going down to size.




The extra holes in the centres of the rods will actually have small steel decorative finials fitted (6 off overall), just to finish them off.


This isn't completely finished yet, that all happens when I prepare them for polishing, but they look a lot smaller in real life than they do on a drawing.



Now up to date with regards what came from the other site.

John

[chuck foster]

well it is GREAT  to see bogs back at it 

like others have said there is allot to be learned in johns writings.................now if i could just remember what i learned   

john i will be following this build as it progresses.

chuck

[lazylathe]

Your coordinate feature on your DRO makes me jealous....
All the holes line up and match perfectly!

Great updates and a ton more useful info supplied gratis!
 

Andrew

[Bogstandard]

Andrew, since fitting my DRO, everything has got much easier for me. All bits like that help to keep myself in the shop a lot longer, years instead of months.
##############################################################################

Using my horizontal belt sander, the top and front previously machined faces of the water jacket and the other rough fettled faces were given a good going over. The only one left untouched was the base which I had machined up. I will also be giving it a dose of heavyweight grit blast, and if the surface comes out well enough, I just might not paint it.




The jacket also needed to have the stainless studs fitting. The build calls for hex head bolts, but I always think that covers such as this always look better with studs and nuts.

So it was just a matter of putting a nut and washer on the threaded rod, screwing it into the hole and tightening up the nut, followed by a quickie chop off with a reinforced cutting disc.




Soon done.




The first of many disassemblies. This time to Loctite the studs into their holes.

Once set, the whole lot was reassembled, with just one washer under the nut. Normally, I would fit two, chop off the exposed stud, remove one washer and they would all be nicely the same length protruding from the nut.
This time on final assembly there will be no washers fitted because they extend out over the edge of the cover, as the bolt holes are very close to the edge because of the graphite block needs some space in the middle to move about. The nuts fit perfectly to the edge.




The uneven lengths of studding were soon machined down to just above the nuts.
I wish someone would come up with a tool that does backwards countersinking. Place on top of the cut stud, give it a turn, and a nice chamfer is put on the end.
I must think about making one.




Finished off nicely.
In fact it will need another strip down to not only finish off the jacket, but also seal things up. But as it is, it should be fine for trial runs.




Another thing I have been pondering over is running this shaft in just drilled holes in the casting, a thing I personally don't like, so I took the decision to ball race it.
I had bought some nice 7mm diameter low profile ball races a while ago from China, and because there shouldn't be much heat in the area, I decided to leave the rubber seals in. This serves me two purposes, the action will be much smoother with less friction, and I won't have to make and fit the required oil cups.
They will be hidden from view on final assembly.
If you notice, the holes in the upstands aren't central, they were drilled to dimensions required on the plans.




Because I had previously machined up datum edges on the base casting, it was dead easy, using the DRO, to pick up the holes again.




First off, the hole was gone thru with a 5mm milling cutter, just so the original holes didn't interfere with the running of the shaft.

It was then followed down with a 7mm cutter to a depth of 2.5mm, diameter and thickness of the bearings. This was done to both upstands.




Ballraced shaft done, and I am now a lot more happy.




The next job concerned the camshaft follower arm, it required a 1/8" offset joggle putting into it.

By heating up just the part that was affected (the black bit), that area was annealed, to make it softer for bending. Just heat up to an orangey red, and either leave to air cool, or as I prefer, because it is quicker, quench in cold water. Both ways work just as well as each other.




A little bit difficult to see, this is how I set it up in the vice. A 1/8" parallel either side, at the position of the start and end of the joggle. The vice was then tightened up and left for a few minutes.
Once taken out, it only required a tiny amount of hand tweaking to get it perfectly in line, and by the time I had finished, it had work hardened almost back to normal. It will carry on age hardening over time.




You will also notice that I have cut a small recess in the crank disc, this will be filled with engine colour paint to give a nice contrast.
It is now starting to look like a finished engine.




Methinks a little more polishing and loads of fixings to be made.


Mainly things you don't consider take much time, but actually do. Making up bearing spacers, silver soldering a few bits 'n bobs together and drilling and tapping all the grub screw holes, plus working out how to get around bad practices on the original build. There is no way will I Loctite a couple of bearings to a shaft, then Loctite the bearings and shaft down into a hole, I want it to come apart without too much trouble whenever I want.




It is all mainly tiny steelwork from now on, special bolts, tubular rivets, little bling buttons, springs etc.


John