I could not induce my Southworth steam powered boiler feed pump to work.
Initially I thought that it was a bit tight, and spent time easing the glands, and slightly deepening the O ring grooves. That took a couple of days. But no luck.
So today I took it to our model engineering meeting, with some tools to perform a tear down, and 2 of our senior members took a close look. After some to-ing and fro-ing, the verdict was that I had reversed one of the steam passage blocks, and machined it back to front. I had mis-interpreted the plans. It was due to not really knowing the rules for rotating a part in 3rd angle plans. Pretty annoying. A 3d view of the part would have removed any confusion. Fortunately the fix was not too complicated. 2 threaded holes to fill, and 2 new holes to drill and thread on the other side.
That done, I re-assembled the steam engine side of the duplex. Hooked up a compressed air hose, and see the result….
This is on approx 10psi air. There is no load, so it is running faster than it would if actually pumping water under pressure.
Next I will mount it to the boiler base, and hook up the pipes. Then there will probably be another video.