Help with gears

[Mem10]

Hello, I’m trying to use stock gears in my engine project but find that they need machining to work. Can anyone explain a good way of holding a gear so the interior can be machined out without destroying the teeth. It also needs to be threaded. I’m thinking a split mandrel with a clamp that reduces it size may work. Any ideas would be appreciated

 

[ChazzC]

Hello, I’m trying to use stock gears in my engine project but find that they need machining to work. Can anyone explain a good way of holding a gear so the interior can be machined out without destroying the teeth. It also needs to be threaded. I’m thinking a split mandrel with a clamp that reduces it size may work. Any ideas would be appreciated

Clamp to faceplate or clamp to a rectangular fixture plate and hold the fixture plate in the 4-Jaw (makes it easier to dial in the bore. Use spacers between the gear & faceplate/fixture plate.

 

[gbritnell]

Take a piece of round aluminum a little larger than the OD of the gear and half as long as the jaws on your chuck. Put the stock in the chuck and mark the number 1 jaw location with a marker. Nobody the stock out. The first diameter smaller than the OD of the gear and the second diameter so the gear will just slip in. Now remove the stock and saw through 60 degrees away from your mark. Now place the gear in the sacrificial collet and remount in the chuck lining up the mark with the #1jaw. Most chucks will repeat very closely to the same diameter stock. You can run an indicator on the face to get it dead square, if required. Now do you machining.

 

[michael-au]

This is how I have held gears to be machined, The recess was just under size but aloud for a nice push in fit, and with light cuts the gear did not move
You could drill and tap a hole for a grub screw in to the side so a pointed grub screw could be very lightly screwed down so the gear will not spin when tapping it
Or as above post says cut a slot to pinch the gear