A "Different" Different Opposed Piston Engine

[GailinNM]

After I completed my first Opposed Piston Engine
http://www.modelenginemaker.com/index.php/topic,2422.0.html
Brian Rupnow started a Different Opposed Piston Engine
http://www.modelenginemaker.com/index.php/topic,2877.0.html

Since Brian so generously posted drawings of all the parts and had such a beautiful build thread on his engine I started building one with a few changes to suit my personal preferences, practices and tooling.

I sent Brian a photo of some parts and he said he would not "object" to me starting a thread on my build. Knowing Brian, this sounded like a direct invitation. Since his thread is so complete this will just be a more or less photo essay with notes where I did something different.

First off, Brian likes larger engines that I do so this 1/2 size of Brian's. This makes the fasteners come out a little weird in some places, but roughly 1/2 size, ie 0-80 in place of 5-40.

To get started, I have brazenly plageurized Brian's thread for a concept drawing of his engine. His engine has changed some in details as his build has progressed but this is a pretty good representation of what his and mine will look like.



Gail in NM

[Brian Rupnow]

Go for it Gail!!! As we both know, "Imitation is the greatest form of flattery", and I mean nothing bad by that. Your work inspires me at all levels, and I take it as a great compliment that you are building the "different different opposed piston engine".---Brian

[Tennessee Whiskey]

Oh yeah, "Dueling Opposed Engines". Now this is something an old redneck can sink into his recliner and watch. I'm digging it.

Whiskey

[steamer]

Now this is going to be good.

.....we need a smilely eating popcorn emoticon.....like the old place.

Gentlemen....please proceed!

Dave

[GailinNM]

Thanks for the blessing Brian.

Whiskey: Well Brian is way ahead of me.  But he had the drawings first.  As far as dueling goes, it will be like David and Goliath because of the size difference.  Brian's will have weight advantage but I bet mine will run faster.

Dave: All in good fun. You have to supply your own popcorn and we will try to provide the movie action. Maybe even a happy dance at the closing credits.

Gail in NM

[steamer]

Thanks for the blessing Brian.

Whiskey: Well Brian is way ahead of me.  But he had the drawings first.  As far as dueling goes, it will be like David and Goliath because of the size difference.  Brian's will have weight advantage but I bet mine will run faster.

Dave: All in good fun. You have to supply your own popcorn and we will try to provide the movie action. Maybe even a happy dance at the closing credits.

Gail in NM

Oh this is going to be EPIC!   

Gentlemen!   Start YOUR ENGINES!

[Tennessee Whiskey]

Dreadnaught and mandolin together make beautiful music. I'm here till the "music" begins.

Whiskey

[b.lindsey]

EPIC indeed....should be fun to watch.  Gail....I tend to prefer smaller also, so will be interested to see how it scales down.

Bill

[GailinNM]

"Gentlemen!   Start YOUR ENGINES!"
Patience Dave, Patience.  Every engine comes to life in it's own time.

Bill: It's scaling up that is a problem.  More expensive materials. Bigger machines. More display space when they are finished. Just ask Brian about display space.

Lets get started with the crankshaft. Of course I could not leave well enough alone. Brian built his up, but in my size it is easier to turn out of the solid. 
The crankshaft started life as a length of 3/4 inch diameter 1144 stress-proof  steel.  The ends were turned down to 3/16 diameter.  I added a little bit of length to the flywheel end and turned it to 4mm diameter.  This is for a one-way bearing/clutch for a built in started that I want to try. That end was drilled and tapped 2-56 to hold the bearing in place with a washer.  The starter may never happen but at least I can put it on if I want to.

The center of the blank was milled to final thickness.

And the crank pins roughed out on the mill.

And looked like this ready to go into a turning fixture in the lathe to finish the crank pins.

Here is the finished crankshaft in the turning fixture after the pins have been turned and finished.

Gail in NM

[Alan Haisley]

What Eric said.

Alan

[Roger B]

It looks like opposed piston engines will be the norm by the time I get round to building my 1898 Saurer replica 

Keep up the excellent work  I will be following if not always commenting.

[cfellows]

Interesting build, Gail.  What do you plan to use for ignition?

Chuck

[Don1966]

Count me in on this ride Gail. You sure are off to a fast start I missed some of already. Man you don't mess around. Your making us southerns look bad.........

  Don

[GailinNM]

Thanks for the kind comments everyone.

Roger: We all will be looking forward to your Saurer build. It should be a fun one.

Chuck:  I will be using a CDI unit from CNC Machine.  I have used about a dozen of them with no problems.  I just get a bare bones unit and make up my own Hall Effect pickup and custom wiring.  A shop built spark plug will be used and I will detail that out in this thread soon.

Gail in NM

[GailinNM]

A few more parts. The rocker arms and the cylinder center block are probably the biggest pain in the rear of all the engine parts.

The cylinder center block is to Brian's drawing except 1/2 scale or course.  There will be 4 more 0-80 tapped holes to retain the valve cages eventually.  I found room for them and have them on my drawing.  I will put them in later when I detail out the retainers and am sure they are OK.

The rocker arms are to Brian's scaled print. I made them out of 2024 aluminum because it has good wear properties running on steel shafting.

The crankshaft you have already seen. Notice that there are 2 ball bearings on it. They are FR166ZZ. I prefer ball bearing to sleeve bearing.  I get my bearings from AVID R/C. 
http://www.avidrc.com/product/9/standard-bearings/
Most of their small standard bearings are US$ 1.00 each and they have good shipping rates. About US$ 1.50 for 20 bearings first class mail in the US.  Same day shipping in most cases.
Gail in NM