Engines > From Plans
Elmer's Oscillating Cylinder Engine #42
EricB:
At long last I've started on my second steam engine. I have another PMR casting kit sitting on the bench but I decided to try one from scratch instead. I didn't think this engine would be too complex. I'm down for materials and I managed to break my lathe drilling out the cylinder, but here's what I have so far.
I was using a 3/8" drill for the final pass in the cylinder before finishing with a boring bar. The drill caught in the brass and quickly welded the MT0 chuck adapter into my tail stock ram. :'(
cnr6400:
If the ram is through-drilled, just heat the end of the ram with the stuck arbour in it close to red heat, and bash the arbour out with a hammer and a suitable sized punch. Hold the ram in a sturdy vise with soft jaws in it for the bash fest.
Is the ram from a Sherline or is it a Chinese import? If Sherline or Taig or other make of lathe made in USA you may be able to get a replacement ram. With Chinese ones you might be able to get a new ram from the importer but it may or may not fit. Seems parts interchangeability is not a given with the China machines, although purchase price is low.
gary.a.ayres:
Commiserations on the mishap. Part of the territory, but a real pain when these things happen.
Some nice parts you have made already though...
EricB:
--- Quote from: cnr6400 on March 02, 2021, 10:02:17 PM ---If the ram is through-drilled, just heat the end of the ram with the stuck arbour in it close to red heat, and bash the arbour out with a hammer and a suitable sized punch. Hold the ram in a sturdy vise with soft jaws in it for the bash fest.
Is the ram from a Sherline or is it a Chinese import? If Sherline or Taig or other make of lathe made in USA you may be able to get a replacement ram. With Chinese ones you might be able to get a new ram from the importer but it may or may not fit. Seems parts interchangeability is not a given with the China machines, although purchase price is low.
--- End quote ---
I did manage to get the adapter out of the ram using the leadscrew but both the parts are ruined.
My tools are Sherline. I should have the replacement parts in a few business days. The ram is ground to fit the tailstock so I had to give them the OD for them to match it.
I just thought that if they sell a 3/8" chuck it should handle a 3/8" drill right? Well maybe not. That was the first time I tried it and probably the last.
cnr6400:
Chris Rueby (code name crueby in this forum) is an expert with his Sherline tools and he could probably comment whether 3/8" drilling in brass is advisable / possible or not in your Sherline lathe.
Any twist drill as it comes from the factory will tend to snatch in brass. You can grind flats on the cutting lips of the drill parallel to the drill's axis for drills you plan to use only on brass, which will reduce the snatching tendency. However such drills will no longer cut steels well, if at all.
A better way in your machine may be to drill a smaller hole to start with and progressively bore it out in small steps to whatever diameter you need in any material. Much less risky for your machine and a lot less drama. The holes will be rounder as well. :ThumbsUp:
Glad to hear your replacement parts are on the way. Good luck with the engine! :cheers:
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