pic: Milling Fixture Up Close

[Jon Jack]

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[Cory]

How come you guys chose to do this instead of machining soft jaws?

It seems like the potential for your gears to move around if the pockets aren't dead nuts on the OD of the gear could lead to scrapped parts. That also seems like it might have some rigidity issues, with such a thin plate overhanging the side of the vise. Do you get chatter?

Looks like it works for you though, and I suppose that's what counts

[Jon Jack]

The reason we chose to try this was to cut down on the number of setups from last year.

There are also some operations we run before we run the gears in the fixture. First we remove the hub and face the gears, (if needed) broach the gears, then set them in the fixture. One of the gears (the one in the lower right) is cut from gear stock, so it must be cut, faced and broached prior to being set in the fixture.

Those gears aren't going anywhere inside that fixture, if they're put in right. They're in there pretty tight and it's just about impossible to move that plate the way it's mounted held in. Not only is the plate held in the vice, we also used jacks to balance the plate. The first time we posted the program and ran the gears there was some chatter, but we eliminated it by manually changing the tool speed and feed rate. After the first run we went back and reset all the speeds and feeds in CAMWorks and reposted the program.

So far we've made probably 12-15 gears and have only ruined one gear from it shifting because it was not put in the fixture properly.