Bottle Engine 3D Model

[SteamGuy]

I did a quick mock-up for a 20hp Stanley engine, and the question with the Stanley is always "how did they mill the ports".
I understand they had a special machine, which is a neat trick.

I have seen some modelers modify the angle of the valve seat in order to be able to machine the ports in a model stanley, but again, I adhere to the original specs, so I either figure out how to do it like the Stanley's did it, or I don't build it.

[Mike Rometer]

No problem with grey cast for this job but there will be a fair amount of whip on a long-series slot drill (or end mill). Go for as big a dia as you can, though you may still have trouble. The final option is, as you say, an accurately cut over-lay plate, but make it in steel. Gun metal or P/bronze for the valve slide. It will indeed wear in, as do all slide valves.

If milling in brass (or derivatives) use a new or freshly sharpened cutter, and take it easy!

[SteamGuy]

I friend of my Dad's use to operate this Civil War era launch on the Mississippi River in the 1970's. It was a lifeboat off of a large steamer, and was later retrofitted with a boiler and a 20hp Stanley engine.

It navigated the river very nicely at 100 psi.

I saw a post on this forum somewhere about using a Mason to power a steamboat.
Yes, it absolutely can be done, if you happen to have a spare Mason or Stanley laying around (some people do).

[Johnlanark]

Hmmm Pat you’ve set us a challenge to find a way you can machine those Stanley valve faces. Here’s my tuppence worth.
Assume that you will core the steam passages, with the inlet and exhaust ports on the faces cast undersize. From the drawing below, it seems that the surface that will form the finished sliding area is raised slightly from the general cylinder, so you would cast this flat with a machining allowance.


If you hold the cylinder casting on your milling machine table with the large inspection hatch upwards, then you could use a small right angle drive like the Bridgeport No 4 here, or a similar home made one
http://www.lathes.co.uk/bridgeport/page6.html
To first of all machine the ports to size using endmills, feeding on the Y-axis. Then use a fairly small diameter flycutter to finish the surface. Would that work? John

[SteamGuy]

Until I built a furnace last year, everything I designed prevously was from a built-up approach, and so I would have made two cylinders and silver soldered them together.

I have pondered the Stanley ports for many years, and have never seen a photo of their angle mill, but it must have looked like the one you posted.

I also thought about some sort of angle shaper arrangement, but I don't think that would work.

It seems like an angle milling attachment would not be that difficult to make, since you would cast an undersized hole in the valve face, which would reduce the amount of cutting required.

I would probably disassemble either a dremel or a die grinder, and then rebuild it into an angle cutter. Maybe they make an angle die grinder already that could be adapted.

All you would have to do is raise and low the mill table while slowely feeding into the bit. I will do some internet searching for and angled die grinder.

[artemis]

Hmmm Pat you’ve set us a challenge to find a way you can machine those Stanley valve faces. Here’s my tuppence worth.
Assume that you will core the steam passages, with the inlet and exhaust ports on the faces cast undersize. From the drawing below, it seems that the surface that will form the finished sliding area is raised slightly from the general cylinder, so you would cast this flat with a machining allowance.
...

The reason the valve face is raised is to permit the valve to "over travel" the valve face, thus preventing a build up of material at each end of the valve travel.

This "raised" valve face also allowed the valve face to be made of a separate piece of material, set in a slightly recessed "holder" in the valve chest, probably with a "paper gasket" between it and the valve chest to prevent steam leakage, and fastened with countersunk flat head machine screws. This in turn permitted the valve face pieces to have precisely machined ports and also the replacement of worn valve faces could be accomplished without dismantling the engine.