22Lt top box mounting plate.

[Martin]

Due to the 22Lt top box mounting plates seeming to disappear I thought I'd look into whether it would be possible to make them. The guys in the foundry decided to fit it with reinforcing. This has now deemed to be unnecessary as pushing the pattern a little deeper into the mold is all that is needed. The steel cam lock was initially made in two pieces and silver soldered together. This was found to be time consuming and future ones will be cast in brass using a pattern.
Regards Martin.

22Lt mounting plate 1.png (43.6 kB . 768x576 - viewed 649 times)
22Lt mounting plate 2.png (32.72 kB . 768x576 - viewed 615 times)

[natalena]

Really cool project. Are you mechanically pressing, or using a hydroform mold? Staying with the original steel construction? Cheers

[Martin]

Natalena the Trades Guild are sand casting out of aluminium slightly thicker than the OEM steel. The extra thickness is achieved by pushing the pattern into the sand on one half of the mold before casting. A couple of methods were tried to make the cam locks that attach to the plate, a two parts steel silver soldered together. Also tried casting off the original cam lock. Eventually decided to make a camlock pattern and cast it in brass and then finish it off which hasn't been tried yet.
Regards Martin.

[natalena]

+1 with the usage of Aluminum. The OEM plate has a lot of slop, and I always thought an aluminum plate would be less rattle prone and could be made thicker.

[alexg]

Martin, not a small feat to make an alu casting that thin. As a metallurgist, I am interested in the method: heated sand mold? high Si (piston stock) alloy? what else? I am impressed!
Alex

[Martin]

Alex all done by our resident foundry Gurus. They are sandcast out of a pattern as in an OEM 22 Lt plate, and I believe they used high silicon aluminium. The head of the foundry Doc is pretty clued up when it comes to what metal to use for the best results for a particular job. The Guild has a pretty varied range of retired tradesmen which cover a lot of subjects from furniture restoration, toy making, CNC machining, and fitting and turning. Current project for the machine shop is building a CNC machine. We've already built a CNC/ computer plasma cutter for the neighboring Blacksmith. We run three days a week Tuesday Friday and Sunday but we've slowed down a bit due to Corona. See here for more information.  http://northpinetradesguild.org.au/
Regards Martin.

[alexg]

Martin:
I looked at the web site. Seems to be a fun place to meet interesting people! Enjoy.

[Martin]

It keeps me out of trouble, mostly. I seem to be busier now than when I was working.
Regards Martin.