Forming Acetal gears.

[The Artful Bodger]

Some weeks ago I showed how I had heat formed some lightweight ABS gears and Evan tried the same with Acetal. If I recall correctly, Evan tried heating the blank but the forming failed.

Now that I have some black plastic which is probably not Acetal but I tried it anyway. It is much harder than the ABS was and there was no sign of it forming without added head.

This time I put the blank on an arbor in the chuck and mounted the steel gear on the tool post, I pressed the gear against the rotating blank which started the familiar rumbling sound then I put my heat gun to the edge of the gear and when the rumbling eased I advanced the feed and repeated until the teeth were formed at full depth. Success!

Well formed teeth that appear to be full strength but I can not get rid of the hairy edges!

[Tony Ennis]

Load the 'hairy' gear with grease and proclaim victory.

[dp]

So, would that be hobbing or forming?

[Black_Moons]

Yea, Call the hairs 'Oil wicking surface' or something

Nice job.

[The Artful Bodger]

Yes, obviously the technique needs a bit more development!

[Dan Dubeau]

So, would that be hobbing or forming?

fobbing, or horming

[TGTool]

Would the hairy gears and unusual technique make this guerilla or gorilla machining then?