More Elbow room...

[Cedge]

I got the camera out to day and shot fresh photos of the Elbow engine project. The shot below shows the engine during a test assembly. The pistons are a bit longer than the drawings and the dual circles of balls were a temptation that I couldn't resist. I've animated the movement on my computer and it should be fun to see when I get it running.

I've been lusting after a 10 cylinder Elbow Engine ever since I saw Don Hall's running at Cabin Fever. I was not particularly taken by the LMS supplied design, but I went as far as to contract with Don to build me one. His wife was taken ill and he never got around to building it, so when the discussion here turned to the Elbow engines, I knew where I wanted to go with mine. Thanks for the offer, Don, but I'm happy now that the deal fell through.

I really like the Popular Mechanics design but I wanted someting that fit into my collection a little better. Solution... combine the two ideas and add a few of my own. Afterall, drawings are just maps to get you pointed in the direction where you really wanted to go.

Hoping you like the results so far.
Steve

 

[Bogstandard]

Looking great Steve.
The 'bobbly' bits should be mesmerising.
Why not throw down the gauntlet and see just how many pistons can be made on a standard diameter cylinder.
I for one won't take you up on your challenge, but someone else with a bit of imagination just might.
Absolutely beautiful work, a credit to your craftmanship. Something to aspire to.

John

 

[Cedge]

John
Thanks for the encouragement. I'm afraid I'm operating at the ragged limits of my ability at the moment. Five 1/4 inch holes is all I can see fitting on a 1 1/8 inch diameter cylinder effectively. Six will fit, but I'm not sure you could crowd the needed 7 into the space. This engine appears to need an odd number of holes per cylinder bank to operate properly. I doubt the visual effect would improve all that much either. Truth being told, it's still just a Popular Mechanics Elbow with a bit of eye candy added...LOL. It's part of my graphics artist past that won't seem to go away.

I can certainly appreciate the hard work put into each one and every one of one these engines, as they are being built .No gauntlets being thrown down here. I'm just used to boxing myself in a tight corner and then working my way out with as few screw ups as possible. This project alone has generated two cylinder banks which are too short for the engine and a pair of pistons that are only good to be used as cylinder hones, so mistakes are not that uncommon here.

Best
Steve

 

[1Kenny]

Boy, that is nice and it has style!

Steve,

Is there any chance you could show a picture of the air ports?

I am still on the base of my elbow and just working on making the column square. You guys have put the fear factor in me to make sure the engine is square.

 

[Cedge]

Thanks Kenny. Which ports are you referring to? The ones in the base or the ones in the bearing disk? I'm not drilling mine through the base on this project. I like the mechanicalness (is that a real word?) of these little engines and will be running my lines atop the base so that nothing is hidden.

Don't let the "square" requirement spook you. As long as your base is nice and square, your turnings are true and you get all the holes bored straight and evenly spaced, the rest is pretty easy to adjust. You'll be shifting the column around a bit when it comes time to dial things in so don't get carried away with locking it in position just yet.

I'll take a photo of the bending jig I made. It made the bends as easy as it gets and got them very close to square. . Squaring the pistons is as easy as holding one end against a square and looking for light gaps under the other end of the piston. The human eye can detect as little as .0005 in deviation, even wearing glasses. It took all of 10 minutes to check, adjust and double check all 5 pistons for square.

John shared an important secret in one of his posts. Typically I have a can of WD40 sitting close at handl to slick things up when needed. It won't help much with the Elbow engine. He mentioned using grease to lubricate his engine. This one is improtant on more than one level. The engine is notorious for throwing oil since it's not a sealed system. Grease is less likely to get spalttered about, but even more importantly, it fills in any small remaining grooves , even after honing. It also acts as an air seal which improves the interaction between the incoming air and the pistons. The reduction in friction was immediately noticable when I switched to grease instead of using my trusty can if WD40.

Steve

 

[Bogstandard]

Hi Steve,
I think it was Rick who shoved the grease in to get it running. But I did mention about WD40 and 3 in 1 being not very good for initial running in.
But one thing I do do is use the left over STP that won't come out of the bottle when you first pour it out.
I've got some about 10 years old and when I first try to get an engine like this running in always put a bit on the pistons, it must work like Rick's grease solution. The only problem with it is that the bits keep slipping out of your fingers as you try to assemble.

John