Armrest started

The first steps for the armrest have begun.

After the wristrest there’s the armrest 🙂

The original construction of the armrest is really tricky.

(c) unbekannt

The rod adjusts the height and is held in place through a pin which itself can be moved by the small lever, the whole assembly is then screwed to the wall in some weird angles.

(c) Martin Schmitt,

My version will not be totally accurate since I’m using a 50x30x2mm steel profile I had in my stash.

Of course I made a FreeCAD drawing of the hole assembly to test the fitting and position of the parts.
Only the total length of the body will be decided later, when I can position the first parts inside the cockpit.

I got the ellbowrest part ages ago from another pibuilder, I think it might be made out of delrin.
Maybe it would have been possible to print it, but I’m pretty sure the cast part is stronger.

So the first step was removing all the overspill of the casting mold.

Secured tightly in the vise.

And then making a lot of chips.

Looks much better now.

The next part to work on was the housing which was also done on the milling machine.

18mm holes for the rod on the short side.

Remount and mill the slots for the fixing lever.

Since a round milling cutter doesn’t produce square corners it needed quite some strokes with the file.

That’s the first steps on the housing done. As you can see on the markings I plan to round over the front like the original part.
But this work will be done when everything else fits together well.

Last step for today is the height adjustment rod which I just turned down to the correct diameter.

At the end it’s been a perfect sliding fit, nothing wobbles and slides perfectly.

That’s the first part done – next are the fixing mechanism and the slotting and drilling of the rod.

When the frontpart is done and working, I will be able to get the last needed distances, position and angles for the mounting plate.

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