Tuesday, May 31, 2022

Aluminium rear

The rear of my "chassis" is not load-bearing, as the engine supporting part of the frame is in-board. So the rear portion of what will originally have been the chassis is far lighter, as I have made it in aluminium. This unequal aluminium comes in at 1kg per metre, as compared to the box section steel which is 2.2kg/m.





I gusseted it roughly every 10mm along the top, narrower surface, then bent it gently over a wooden former to make the base of the tail section, which will be held in place riveted steel out-riggers.

I have never welded aluminium. The trouble with the stuff is that, being soft, it tends to be distorted by the rollers which propel it out the end of a welder, and because it is very soft, is inclined to be slowed inside the welder liner through friction....and becomes snarled up into what is called a birds' nest. It is a bit of a nightmare. To get around this, the spool-gun was invented. This reduces the length of journey the al wire makes from the reel to the tip of the welder, by putting the spool at the back of the hand-held gun. But there is a problem, my welder isn't compatible with them (unless you get a universal spool gun costing about £600!) The alternative is to put a more slippery silicone liner inside the welding gun, but my welder's roller mechanism cannot take v-shaped rollers for pushing the wire, so that it is inclined to birds'nest at the welder end.

Bugger!

Either I need to get a whole new system or get a friend to weld the thing for me. Of course, I'd rather do this myself, but my friend may the best option.

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