Still more Alodining (Mar. 25th, 2002)

It has become almost a habit: every year when the temperatures rise I'll start alodining the aluminum parts I had manufactured during winter time. When the thermometer climbs above the 20 deg. (Centergrade) limit I'll start spray-priming them. This I can do until my trees develop small fruits. Then the last chance for spraying two component primer has gone and I'll start assembling/riveting larger components of the craft.

This are some of the wingrib fittings, still dirty

this are the fittings how they came out of the alodining bath. The parts are already pilot-drilled to the mainspar (and if I should accidentally would mix-up these pieces I'd have a LOT of trouble [because all left/right markings and numberings have gone during this process]).

This will become the baths for the wingribs. the frames will be layed-out with plastic foil.

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Cutting Nylacast (Mar. 9th, 2002)

The pivot blocks are made from Nylacast. Working at the lathe at slow cutting speed delivered nice, smooth surfaces.

Bot how to grind this 1" holes?

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what happened lately:

experimenting with an inexpensive electric flap drive

a little analysis about pulling 120deg blind rivets into 100deg dimpled holes

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Cutting Nylacast (Mar. 2nd, 2002)

Cutting Nylacast is a bit tricky. It threw off the blade two times from my bandsaw. Then I started investigating the problem a bit closer. This is the rear side of a Nylacast block with a test cut. One can easily see that kindof a 'wool' has build up. This happens because I cannot regulate the speed of my bandsaw. The saw runs continuously at 1200 RPM which is way too fast. The material locally melts and forms this kind of threads. If the cut has advanced about 1/2" then the tread buildup is so heavy that the blade refuses to cut any further. However the 'wool' can be removed easily with a sharp knife (or even fingernail). Another alternative would be to use the handsaw. But this is very exhausting and the blade tends to wander off the cutline.

Drilling Nylacast is easy. Just put the drill to low gear and use a good push. Then the inside of the hole becomes mirror-like. If the speed is too high then the material melts and the drill bit 'grips' (and the part may spin around).

One of the next days I'll use the lathe to finist the parts to final size. Cutting speed will be set very low, no cooling liquid will be used.

to be continued...

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