Another Diversion from The Triple
by John
My model engineering club (GSMEE) has an annual competition build. This year it is a small horizontal reversing steam engine.
So I have taken another break from the triple to build the HME. I have redrawn the plans to make my model 40% bigger, and also to accept metric fasteners.
The HME blanks for the base, the cylinder block, the flywheel pillar and the flywheel. The only stainless steel I had in my junkbox, er storage facility, had a big hole in the middle, so I filled that with brass.
All was going well, and I spent almost a day making the piston head guide. Then finished off by making the guide rod and block. I decided to take another thou off the guide block, and set the lathe going.
And heard an ominous bang.
I had forgotten to remove the piston head guide from the from the piston before I restarted the lathe. Destruction. The lump at the bottom is another piece of brass, ready to be turned into another head guide. I had run out of suitably sized brass, so I silver soldered a length of rod to some square section. A day later and the new piston head guide is now made.
At least I know from this (and other crashes), that the second part is always made much faster than the first.
And on a different subject, I recently bought on Fleabay a self centering 4 jaw chuck.
It does not replace the independent jaw 4 jaw chuck for accurate work, but will be useful for turning small square stock. Also, I plan to make a backing plate for it to fit into the tailstock, so it will hold taps.
johnsmachines 
I bought a small self centering four jaw chuck from ebay. I was going to use this just like you have done. It was to be used as the equivalent of a square collet chuck for use when using the capstan.
however, the accuracy of the jaws was so poor that the chuck was useless.
The inside faces of the jaws did not meet up when the jaws were closed.
john f
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Same. but I will use the tool post grinder to improve the accuracy. john.
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Thanks for the hint – google showed me the way to other Elmer engines. Probably old hat to you, but just in case http://www.john-tom.com/html/ElmersEngines.html
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Thanks Russell, I was not aware of that site. I will look closely at his other designs. I have the plans for the HME to be excellent (except that I have to convert them to metric) John.
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Hi John
Thanks for the updates on the Triple progress. I have attached a couple of shots on my progress.
I bought the castings in the UK many years ago and started building late last year. I am following the Bertinat drawings and description. My casting set did not include connecting rods and as you can the see the base plate is aluminium.
I sealed the condenser tube plate to the condenser body with high temperature sealant (up to 340 deg C ) before soldering the tubes into the tubeplate. The sealant survived the soldering heat but I had three leaky tubes. I pressure tested the condenser with air at 20 psi. Two of the leaks were sealed by peening and one was re-soldered.
Attached are two photos of a recently completed compound under-type engine. The patterns and castings were made locally to drawings from the Uk. It is a bit deceiving as it does not have a boiler. I thought that it would never get finished if I had to make a boiler, so I made it look like it did have one. It is complete in every other detail and runs well on compressed air.
Thanks for your Blog which I look forward to reading.
Regards
Roy Armstrong
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Hi Roy, unfortunately the photos do not show, probably a restriction of the site. I would like to see them. You could send them to me at jviggers@iinet.net.au John
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