Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I drilled the locking screw hole in the flywheel. Spot faced first, then center drilled, then the tap drill. I have this nice ER11 collet holder which lets me get in to tight spaces such as this, and makes the drilling and tapping a breeze. Much better concentricity than a pin vise style holder.





Couldn't use a tap holder, so I just used the ER11 set up to hold the tap. Disengaged the gears and turned it by hand.



I then spent some time doing some assembly. This is what I have so far.









I got this far, and was having trouble getting the steam chest cover screws in, and also the screws for the valve rod gland. Not too surprising, since I hadn't tapped them yet.  :embarassed:

Still, I was able to manually turn everything over, and there are a couple of areas that would benefit from some tweaking, so I will strip it all down and address those items, and maybe next weekend I'll be able to give it its first test on air.

I tapped the remaining holes, and reassembled today. After spending a little time setting up the timing carefully, I attached a compressed air line and the engine took off immediately without me having to touch it! You can imagine that I was quite delighted at that. Here is a little video I shot to show it running. I am pleased. It is far from perfect, but it runs quite well. It is worth going the extra distance to now strip it and paint it, and make a base of some sort for it, but otherwise I consider it complete and shall move on to another project.

It runs well at about 12 psi. 10 psi is getting on the edge, and below that it stalls.



The experiment was not a dismal failure, even if not a complete success.

The valve started thus



I filed the edges to be built up to get them clean, and degreased the part in acetone, then set it up on my weld table in a clamp.



Showing the part the business end of my TIG torch. This is a 3/32 electrode, and a 1/16" would have been more appropriate.



Anyway, as blobby as it looks I did manage to build up the edges with some silicon bronze.



After some initial machining and clean up, I ascertained that the silicon bronze was properly bonded to the part, and it actually machined well.



However, I had not built up the edge quite enough, so after clean up and machining I only gained a small amount on each side. At this point I decided I had put enough time into this. Overall the concept showed signs of success, and I managed to build up the tiny part without completely melting it, so I'm pleased with that - but now I'm just going to move on with life and make a new valve.

Here it is so far:



A simple part really, I'll finish it tomorrow.

I have also been painting the engine - I degreased everything in isopropyl alcohol in a cheap ultrasonic bath, then primed with automotive primer, and let cure overnight.



And then made use of my scale model spray booth to paint it, using a tin of RAF roundel blue enamel paint that I've had since about 1996 or something.





It's perhaps a little brighter than I intended, but overall I quite like it.

So - more progress. I have to figure out a base yet, haven't decided what to do for that.