Arnold's take on Elmer's #5 Geared Engine

[arnoldb]

Well, not much happening in the shop; I'm currently spending a lot of overtime on a work project...

I did manage to make a start on the base and bearing blocks.  Cutting thick aluminium can be a bit of a chore, and my "normal" bandsaw blades are a bit fine.  After a trip to an engineering shop - "Give me two of the the coarsest metal cutting blades you have for the 4x6 saw" - I ended up with 10 TPI blades.  Those made short work cutting the aluminium from stock plate, and a quick trip to the mill cleaned it up nicely.  Two bits of 26mm wide 8mm plate for the bearing blocks, and a 140x80mm bit of 12mm plate for the base:

The plate for the base is 45mm longer and 20mm wider than the plans show - this will form one of my changes to the overall looks of the engine.

The bearing blocks was drilled and reamed to 8mm for the crank location - I used the vise back-stop to reference the base position of the blocks.  The short one was done first; next the long one:


Rather than drill through-holes for the gear mounting locations, I drilled blind holes 7mm deep and threaded them M3:


The bearing block mounting holes soon followed:


The long bearing block as shown on the plans has a church-steeple-looking shape to it; a combination of Elmer using his "standard" faux bearing block and extending it for the top mounting hole for the gear.  Also, the rounded top of the block normally extends a bit above the outer circumference of the gear.  I don't particularly care for that look - and opted to "simplify" the bearing block, and bring the top down to the same dimension as the gear OD would have, with a curve to match it:


As it turned out, the angled faces very closely matches a line between the hole locations, so I used a 3mm screw and a bit of rod that had 3mm threads on the end to locate the piece in the vise to mill the angles:


Both sides done:


To make the curve at the top, I used a Dremel drum sander - the chuck visible is a dremel one, but it's actually on an arbor I made a couple of years ago for using small drills in the mill:


The small bearing block got matching angles on the sides, and a round-over with a file. After some clean-up, the main bits of the bearing blocks are done - I just have to make the brass/bronze bushes and press those in:


I roughly put things together in their approximate places for a quick family photo (excluding the eccentric and strap):

  - just noticed the steam chest is upside-down, and it gave me an idea that won't be used though...  I want to finish this engine quite simply; the focus should stay on the gears, and there's a little matter of a very simple old horizontal steam engine that I found locally and should be able to get plenty of hands-on access to - not for restoration (its way beyond that), but to try my hand at making a working true-to-scale model...

Kind regards, Arnold

[joenoci]

Hello Arnold,
See you are always on the go!

Arnold, I have been cutting a fair bit if thick Al plate lately ( up to 20mm)- making the mini CNC lathe, and the small engraver...What works VERY well is to get an Aluminium chop saw blade - has tungsten carbide teeth with a negative rake, and fit it to , preferably,  a radial arm saw, or less preferably, a bench type circular saw. Cut slowly, with some lube ( I use simple penetrating oil in a spray can) and it works very well, nice finish, and can be to within 0.5mm or so.

What do you use for 'marking blue'? Is it a blue permanent marker? I cannot find any of the stuff anywhere - I have a (now useless) spray can of the stuff, but it has seemingly run out of propellant, so no spray.

Watching You...

Swakop Joe

[Don1966]

Great progress and a great write up. Still following you Arnold.................


 
Don

[Tennessee Whiskey]

Arnold old boy, I've never seen any one person that can eyeball this, lazily to do that, and redesign for comfort an engine and have them come out so nice and run so well. A true gift in itself. As my 16 year old granddaughter would say, "You Rock"

E

[b.lindsey]

Still making nice progress Arnold! Nice to see the family shot too 

Bill

[vascon2196]

Wow that is coming along great...looking forward to seeing it run!

This was my 3rd Elmer's build and still the most fun to watch run.

Great job!

[Nicolas]

Still looking good 

[Roger B]

"Not much happening in the shop" is a relative term  you seem to be making great progress    Still following   

[arnoldb]

Thanks for checking in everyone 

Joe, I've considered getting the blade, but my machinery's a bit "iffy" in that department; no radial arm saw, and my circular saw has a small bench to mount it in, but it's not quite sturdy enough, so I'd rather not chance things - I like my fingers...  I keep on meaning to get a variable speed jig saw - I've used my fixed speed one in the past to cut ali, but it's too fast for it.  I've eyeballed the "Springbok" wood/meat saw I have here a couple of times for cutting ali as well, but that machine's not mine, so I've steered clear of using it for ali.  It only gets used to process meat.
Like you, I've also been unsuccessful in finding proper layout dye - so yes, it's just a permanent marker I use.  For larger areas, I have a bottle of permanent marker re-fill ink; to use that, I just take a small piece of toilet paper (every shop should have a roll floating around  ), drop some ink on it and wipe the workpiece.  This works quite well too.  The only disadvantage is that most cutting/cooling fluids tend to remove the marker ink quite quickly; I suspect proper layout dye is slightly more resistant to these.  Oh, and then there's the story of getting "blue" when I started as a complete beginner...  Turned out to be "Prussian blue" - used to check fits.  There was me liberally coating a workpiece for layout with it, and as most machinists know, that stuff doesn't dry out and crawls everywhere on its own accord...  Years on, and I'm still cleaning up that mess 

Kind regards, Arnold

[arnoldb]

On to the base...
Seeing as it's going to be bigger than the one in the plans, I spent some time carefully recalculating the hole positions, and laid those out to visually check that things would be OK.  When it was time to take a photo, the camera's batteries were flat, so I put those on charge, left things as-is, and while waiting for the batteries to charge a bit, turned up the two bearing bushes.  Once there was a bit of a charge in the batteries, I took the photo - showing the layout work and the bushes:


Off to the mill, and I used an edge finder to locate the reference corner I'd based the newly calculated dimensions on.  Then from a list of coordinates I used the DRO to spot the hole locations - everything seemed to match up well:


The bunch of 3mm holes followed - with the addition of some holes in the corners for the flywheel cut-out:


To save some time getting rid of metal, I poked a couple of 12mm holes into the flywheel cut-out:


Those were followed by a 12mm milling bit, and I used that to also get to 0.5mm of final size on all sides of the hole.  No finesse here; just hogged out metal:


A 6mm cutter followed - at a more sedate pace to get things to within 0.1mm of size, as well as to get closer into the four corners, and as a last step, I ran around the edges with a 3mm mill to match up to the holes that was drilled in the corners and taking away the last 0.1mm: :


To complete the machining on the top of the base, I ran around the edges with a 6mm ball nosed cutter - just to add a bit of "looks":


The last machining operation on the base was to flip it upside-down, and counter bore the holes - I first wanted to be lazy and just countersink them, but I'm out of stock on M3 countersink screws... :


After some time with elbow grease, files, sandpaper and a bit of Scotch-brite, the base was done:


It was a quick job to press the bushes into the bearing blocks - no photo of that though, and surprisingly, things appear to fit together - though the cylinder mounting block still needs to be made:


Kind regards, Arnold

[ReFlad]

Love watching you work,  Arnold.   You make it look easy!

Ronald

[Don1966]

Now that's what I call a good looking base. It really turns out great with those added touches. Looking good Arnold.


 
Don

[b.lindsey]

Very nice Arnold...I love the base too!!

Bill

[Tennessee Whiskey]

Dammit man, how do you do it? I'll say it again, " well, I eyeballed this and I fudged that and I decided not to do this and do that instead, and By God, it turns out beautiful. Just amazes me

E

[arnoldb]

Ronald, Don, Bill & Eric - thanks Gents

Ronald, "easy" can be a very relative term.  I'll admit that so far in this build, I have actually found things easy to do.  On the other hand, a mere 5 years ago, most of what I've shown so far would have been extremely difficult for me to do.  Over time I've slowly learned a bit, and refined many operations to suit my tooling and machinery.  Finishing takes a lot of time though.

Eric, there's some simple rules to follow - as long as one understands how the engine works and where the all the critical dimensions are, it's easy to change the cosmetics on a barstock engine.  I'll admit to having built a "mental image" of how I'd like the engine to look when done though - so I'm working to a sort of plan even though its not on paper 

On Friday I had a short bit of shop time.
The cylinder mounting is another bit that I wanted to change.  It's about 16x16mm and 35mm long - with only the height being critical, as that must place the piston rod at exactly the axle center line.  Digging around stock, the closest square aluminium I had was 25mm square - machining that down to 16mm square seemed a bit wasteful.  So a couple of bits of off-cut plate was selected - one 12mm the other 6mm thick:


The 12mm plate was skimmed down to 10.8mm thickness and given a run-around with the 6mm ball nose mill:


Then I clamped the 6mm plate on top of it, and drilled two 2mm holes into it and used some 2mm brass rod to pin the plates together:


The mounting holes was drilled:


Then I bolted the plates together tightly using two 3mm high-strength socket screws, and gave everything another couple of light passes with the ball nose mill to blend the two plates together.  I forgot to take a photo of that - but after a bit of clean-up the base was finished:

Looks a bit ugly at the top, but it's very nearly too low, so I didn't want to take more height off by prettying it up.  The top will be invisible once mounted.

A trial fit - the brush marks are the wrong direction on the mounting, so later on I'll give it a vertical brush finish to match the cylinder:


Kind regards, Arnold