# A Celebratory Engine -Elmer's #8



## arnoldb (Jul 18, 2010)

A year ago this same weekend, I pulled my finger from you-know-where, and built my first running engine

I thought a celebration was in order, following the same rules: Build an engine from start to finish in one weekend. I was wondering whether to build a wobbler of my own design or one of Elmer's ones and mentioned this to Rob Wilson. He promptly suggested Elmer's #8 - Scotty. This turned out a good suggestion (Thanks Mate ;D), as this would also be my #8 engine, and would give a good workout to the new skills I learned in the past year, as well as make use of my significantly improved tooling arsenal.

So I started, and finished the #8 ;D. It took a bit of planning; some parts had to be made before others to allow loctite to cure overnight and so on, but I worked out a sensible approach, and collected materials. This is not a full build log like I usually do; most photos are of finished components, but I did add one that I thought worthy as a tip.

Finished engine photos and video is at the end of the post.

Friday afternoon after work started with this bunch o' bits:






One of the bits of 6mm ali plate was machined into the engine frame:





Another bit of ali became the base:





Then I turned the bearing, cross drilled it for the air supply passage and silver brazed a bit of 5mm brass pipe to it:





Stopped work for the evening with the bearing pressed into the frame with a bit of high strength retaining compound to cure overnight:





Saturday I started by cross drilling the steam passage through the frame and bearing, and made a plug from ali to close up the open end on the frame:





A while later, the cylinder block followed:





Next the piston and rod; as the rod I had available was 3mm music wire, I didn't bother to thread it for screwing into the piston like Elmer is wont to do; I just drilled the piston center on size for the rod, cleaned everything thoroughly, and silver brazed the rod to the piston; much quicker!:





The rod guide followed next; this is the only part I made a booboo on and had to re-do it:





The crank disk followed:





Next I started on the main shaft; it had to be drilled for a length, and two flats machined on it 180 degrees apart to make the valve for intake and exhaust. To make sure the two flats were 180 degrees apart, I clamped a bit of rod to the first flat after I machined it, and turned in the vise; it was then easy to check by measuring down to the mill table that both ends of the clamped rod was equidistant from the table:





The finished shaft; poor picture, as it does not show the longer flat at the back...:





While the going was good, I milled and then turned the yoke from a bit of HRS and stopped for Saturday:





This morning I made the flywheel after I re-made the faulty rod guide:





The slide block was made from a bit of phosphor bronze; I didn't bother to lay it out; just used direct readings from the mill and a couple of calculations - it came out spot-on ;D:





Then I assembled everything, and had a bear of a time to get the engine to run. I traced some binding to the yoke which was just a tad tight on the crank disk; some sanding on emery relieved this. The piston was also a bit tight in the cylinder - it fit perfectly yesterday, but the cylinder block was a lot colder today, and had shrunk enough to cause a bit of binding, so I took some more metal off the piston with some fine emery. Then I added copious amoints of oil everywhere, and turned the engine over for a while with the main shaft gripped in an electric hand drill. After a while, things loosened up nicely, and the engine started on air - though it required about 20 psi. After another 20 minutes of running, it was down to less than 5 psi to keep ticking over.

If anybody want to build this engine, I'd suggest a steel / cast iron / brass flywheel; the aluminium one appears a bit light. I think I'll make a steel flywheel at a future date for the engine, as it is very near to being breath powered - it just needs a bit more momentum.

Photos of the completed engine:





















And the video; this engine is not counter balanced, so it needs something solid to hold it down; I used a small drill press vise:
[ame]http://www.youtube.com/watch?v=C8YMhDmRwVo[/ame]

This was a nice personal challenge ;D - next up I'll make a boring head, and then I'll notch things up with either an IC engine or a flame gulper.

Many Many thanks to all the good members here on HMEM who have contributed your knowledge and experience - directly and indirectly !

Thanks for checking in !

Regards, Arnold


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## SAM in LA (Jul 18, 2010)

Arnold,

Nice engine.

You finished in one weekend 

Did you stop to eat?

SAM


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## TuxMan (Jul 18, 2010)

Arnold

Very nicely done!!!

You were ambitious to try an engine in a weekend but you pulled it off nicely. :bow:

Eric


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## dsquire (Jul 18, 2010)

Arnold

Congratulations. You have came a long way in the first year. I am looking forward to watching your progress in year 2 as well as the new projects that you will attempt. :bow: :bow:

Cheers 

Don


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## larry1 (Jul 18, 2010)

Great looking engine, also great running engine. I'm really surprised that this only took 1 week-end, this is a great build time.Larry1


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## ksouers (Jul 18, 2010)

Congratulations, Arnold!

Wow! Only one weekend! And what a great looker and runner too  :bow:


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## ozzie46 (Jul 18, 2010)

1 Weekend!! Wow!!!

  Good job.

  Ron


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## zeeprogrammer (Jul 18, 2010)

Arnold...congratulations!!

Makes me want to know more about where that finger was...but I won't ask. I'll experiment and hope.

One weekend. I have to admit to being jealous. Real jealous. ;D


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## RobWilson (Jul 18, 2010)

Well i just new you could do it  :rant: :rant: :rant: :rant: :  ;D Rof} Rof} Rof}

Nice one mate :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow:


Regards Rob 

Top job Thm:


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## bearcar1 (Jul 18, 2010)

Man that engines runs smooth as a baby's back side. What a beauty. I am insanely jealous, a little over twenty four hours from start to finish, what did you do Arnold, pee in a can in the corner? Well done, BRAVO!

BC1
Jim


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## Troutsqueezer (Jul 18, 2010)

Way to go Arnold! It's nice to have another build thread on one of Elmer's engines. After some time, maybe we'll have all them. 

How'd you get the parts to come out straight using that curved ruler?  :big:

-Trout


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## deere_x475guy (Jul 18, 2010)

Congrats Arnold, I always enjoy there build pics.


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## Groomengineering (Jul 18, 2010)

Nice one Arnold!!! ...And quick too! Remindes me I've got plans around somewhere for a double scotch yolk, may have to dig those out.

Cheers

Jeff


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## gbritnell (Jul 18, 2010)

Great weekend build Arnold. That Scotch yoke connection to the crank is neat. It looks like it runs real sweet also.
George


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## hobby (Jul 18, 2010)

Very Nice smooth runner.
Sounds great...

Keep up the good work.


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## Diy89 (Jul 19, 2010)

Very Nice!
Thanks for Sharing!


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## arnoldb (Jul 19, 2010)

Thanks Sam - I always make time for a good cooked dinner and quality time for attention to my pets 

Eric, thank you; maybe a bit ambitious, but that's where the challenge lay; I machined this engine "in my head" numerous times to make sure it was both possible and safe to try. I'm sure it can be done in one day, but I like my extremities, so I took breaks when I felt tired.

Thanks very much Don. I surprised myself with how far I've come, but I still have a lot to learn... I have a list of projects that just keep increasing in length!

Larry, Thanks !

Thank you Kevin - I'm going to try a heavier flywheel later in the week; maybe I'll be able to post a clip of it running on breath power - that will have me REALLY happy 

Thanks Ron !

Thank you Carl. Why, the finger was in my ear... :big: Don't be jealous - your life's a bit more complicated than mine 

Rob, Thanks Mate ;D - :big: You better get to it; I'm trying to catch up ;D - now, if I can just lay my grubby fingers on refractory and casting sand... :big:

Thank you Jim ! - :big: I have a bit of garden close to the workshop door ;D - but fortunately the house and amenities are not too far away ;D

Thanks Trout ! - I don't think its a "maybe" - I'm just grabbing what I can! - Metalbutcher is on vacation, but he sure gives them a go, and you and others are following closely ;D  :big: If my parts looks as bent as the ruler, I know they are good to go :big:

Bob, thanks! 

Jeff, thanks. I know I've seen some plans for a double scotch somewhere; I can't recall if those was for an Elmer or someone else's though. Should be an interesting build though 

Thank you very much George! 

Thanks hobby - it kicks up quite a racket if its not on soft padding as it is very unbalanced. I have yet to hear what it sounds like when mounted on a wooden base; I think it will need rubber feet 

Diy89 - thanks, and its a pleasure.

Regards, Arnold


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## b.lindsey (Jul 19, 2010)

Thats a little beauty Arnold. Despite it being a weekend project, each part looks so well finished. Excellent job.

Bill


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## lugnut (Jul 19, 2010)

Arnold, that is a sweet little engine.  What rpm do you think it gets to while your at full speed.  Sounds great also.
Mel


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## Wagner1975 (Jul 19, 2010)

Wow Arnold ... you sure don't waste time! :big: :big: :big: It's so unfair that you have so much time to play! I'm lucky if the misses and the kids allow me 2 hours on a Saturday! ;D
Great engine! Thm:

Regards
Wagner


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## arnoldb (Jul 19, 2010)

Thanks Bill. Its become second-nature for me to have a couple of different grade sheets of emery lying about on a flat surface; as I finish machining each piece, I nearly subconsciously deburr it with a fine file and give it a rub-down on the emery. It helps that I'm getting better machined finishes; less elbow grease :big:

Mel, thanks. I don't know and can't measure the RPM. At a guess that was about 2000 to 3000 RPM at 40 psi - It still wants to go but I'm scared it will break apart as the crank pin is just 1.5mm (just under 1/16") thick and this particular engine design is very out of balance.

Baie Dankie Wagner ;D - Believe me, your 2 hours are more golden than mine; enjoy the missus and the kids - the hobby is a side-line. And once the young ones are bigger, you'll get to spend quality time with them in the shop; better start searching for safety glasses for kids - might be hard to come by in RSA ;D

Regards, Arnold


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## arnoldb (Jul 31, 2010)

A bit of an update...

I mentioned in my original post that this engine could do with a heavier flywheel, so I made one from a bit of 50x10mm HRS flat bar. It runs much better with this - I can even (with a big huff & puff) get it to run for about 10 turns on lung power. Some more running in on the compressor might just turn it into a breath-powered engine, but I don't think it will ever run very well on breath power, as there are quite a lot of "friction surfaces" involved.

Last weekend I didn't do anything in the shop, as I had a bit of flu, but during the week and today I made the new flywheel and a wooden base for it.
I have a router, but could not figure out a way to use it to contour the relatively small wood block... So I ended up with the rough block on the mill, and surfaced it with the flycutter (super-sharp honed cutting edge) and made the decorative sides with a routing bit chucked in the collet chuck - running the mill at maximum speed. Worked a treat ;D. I did not take any photos while doing this; I'll take some when I do a wooden base for a future project.

The new flywheel was also easy - I wanted it a bit more decorative, so drilled six holes in it, and while it was set up on the RT, just milled in the recesses on both sides:






The flywheel is small, so drilling it on the hub for a grub screw was not an option - I did the "grub screw and pin" to retain it; that required drilling a 2mm hole accurately through one of the spokes, and then part-way drilling 2.5mm to tap M3. To make sure I was going smack bang through the middle of a spoke, I used a 6mm drill and a bit of 6mm rod to make sure the spoke was aligned vertically:





So now the engine really is complete - except for a name plate ::

















On to making that boring head...

Regards, Arnold


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## SAM in LA (Jul 31, 2010)

Arnold,

Good looking engine and base. What kind of wood and finish did you use?

I don't think any of my engines would run on breath power unless you had lungs that were the size of trash cans.  ;D

Regards,

SAM


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## hobby (Jul 31, 2010)

Arnold,

That is a real, really nice engine,
You show very nice craftmanship in the machining of all your parts,
and the smoothness of how it runs, is exceptional..
and the display base shows good quality woodworking also..


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## johnthomp (Jul 31, 2010)

wow onw weekend what a challenge ive roughed a couple of elmers engines together in a weekend but my favourite has to be elmers tiny i simplified the stand and cylinder to just square blocks due to not haveing a milling machine and altered the crankshaft valves to have an inlet valve and an outlet valve in the sme style so i didnt have to bore out the crankshaft i took it right up to 80psi on the compressor and it went like a bat out of hell sounded like a chainsaw at full throttle wich is roughly 9000rpm and with the way i did the valves it was not biast to wich way it ran just swap the air line to the exhaust port 
   but i still cant make an engine look as good as that yet well done fella thats an achievement and a half 
   congratulations 
   reguards john


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## arnoldb (Jul 31, 2010)

Thanks Sam

The wood is "Rhodesian Teak" - an indigenous species in the far north-east corner of Namibia in the part bordering the old Rhodesia (now Zimbabwe).

As to the finish, well, it's just sanded smooth, and old-fashioned "hard" floor/furniture wax applied liberally (I use a wax called "Cobra Polish"). Then heated a bit for the wax to penetrate the wood, more wax added as it's soaked up, and later buffed down with a soft cloth to get some sheen. With age and more waxing, the sheen becomes more pronounced. I have a lot of teak furniture that has only ever seen this wax treatment - no oil or varnish; my dining room suite is as old as I am and have a mirror shine from the years of receiving this treatment - photo of the engine on said table, and the wax I use:





And the disclaimer - I use the wax pictured as it works for me as a satisfied customer and have done so for at least three generations of my family - not because of any affiliation to the manufacturers. 

And, Yes, a bit of elbow grease is required  

Hobby, thank you very much for the compliments 

Thanks John ;D. Just stick at it; it becomes second nature to give a quick rub of parts over a bit of oiled emery paper to finish it off - especially to get a brushed finish like on this engine I built. Polishing it is another matter though; that takes time.  :big: Tiny can sound like that if you tighten the spring up to take high pressure ;D - I have my little Tiny set with a feather-light spring pressure; 5 psi would blow the block off the port face. But set like this it's a treat to run on breath pressure alone ;D

Kind regards, Arnold


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## johnthomp (Aug 2, 2010)

another engine ive built and ran to destruction was elmers standby that went really fast till the piston siezed solid in the cylinder and ripped the connecting fod off the crank mangleing the driveshaft in the bearing but was a belting little engine 
  and a little challenge i did was trying to built elmers slider engine but couldnt get the valves to seal properly so gave up on that but the open column with reverse went a treat i built that one for an elderly gent who built wooden rc boats and wanted to make a steam one he loved it 
 reguards john


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## Hat56 (Sep 19, 2013)

Speaking of  Elmers engines I saw a two cylinder wobbler geared to a   single shaft presented by Tubalcain on youtube and he suggested it was a   number 115? made by Elmer. I would like to get the plans for this if   anyone can help.

I have searched the John Tom to no avail.
	

	
	
		
		

		
		
	


	



       Cheers  Hat


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