PM Research #5 "coke bottle" steam engine

[LorenOtto]

View attachment 101623

Good job.

 

[McSummation]

Time for some "Help!"

I'm working on the crankshaft. The casting is so rough that I smoothed it some on my bench grinder. Then, using a steady rest, I used my tool post grinder to grind a round section at the ends. After moving the steady rest to the ground area, I tried to use a center drill. It won't drill. The end is very hard. Have I "work hardened" it? Do I need to temper it?

I'm also working on the frame - on the valve slide guide mounts. Three of the holes drilled and tapped OK. The fourth one won't drill. Could this also be "work hardening"?

 

[mayhugh1]

It's probably not work-hardening. I'm not familiar with those castings, but I assume the crankshaft casting is cast iron. It's not uncommon to run into an occasional hard spot in cast iron where the carbon content wound up too high due to inhomogeneity problems or improper cooling of the melt. Carbide tooling might might get you through it, but if it's too widespread it might be cheaper in the long run to discard the casting and make the crank up from barstock. I understand why many parts are best machined from castings, but some, especially crankshafts, aren't well suited for castings. A better quality part could probably be more easily fabricated from barstock - either cast iron or drill rod plus some bits of hot or cold rolled steel.
I just sold a set of castings for a Challenger V-8 and many of those parts would have been difficult to fabricate fom barstock. But the kit also included cast iron cylinder liners that had been cast with steep draft angles that would be difficult to chuck up for their initial turning. Even worse, the cast iron looked pretty nasty and was probably riddled with hard spots. Those parts would have been much better sourced from a short length of 1" round gray cast iron or even better 12L14 in the kit. Unless you just want to solve the challenge of working with the casting, I'd go the barstock route. -Terry

 

[AlbertdeWitte]

Hi There

I have also built this kit some time ago, it might be a hard spot there, drill with oil and slow speed, sharpen drill often.

 

[natalefr]

Il n'est pas difficile de construire un vilebrequin

 

[Cymro77]

N'est pas difficile pour vous, mes pour moi ouch!!!

 

[natalefr]

I also thought it was difficult, you can find many videos on youtube where they explain how it is done, here is the construction scheme of the Hupshur vertical drive shaft

 

[packrat]

I have a full size steam engine like the one you are building, It came out of a old creamery and milk plant in Orem, Utah.
had to make a few parts for it and was painted black and red by someone ..Have run it on live steam and air, at one time I had a boiler { a 40 HP Case } engine would run real nice on 40 psi of steam..

 

[DougB]

The pictures of my bottle engine I built some years ago complete with generator constructed using a stepper motor. They are quite versatile little engine, enjoy your build.

Doug Baker

 

[natalefr]

Very nice engine !