Rack involute fly cutter - video

[Jon]

Rack involute fly cutter. By Clickspring. 3:12 video:

[tonyfoale]

A rack like any other gear or pinion should have an involute shape but that shape is straight sided for a rack. So the video title is misleading. The fly cutter was sharpened to have flat sides and of course it cut flat sides on the rack.

[Hans Pearson]

The title is misleading, but a rack does have straight teeth. The way a gear exits a rack is slightly different to the way two gears part. I unwittlingly cut a rack with an involute cutter, and I promise you, it does not work well.

[tonyfoale]

The title is misleading, but a rack does have straight teeth. The way a gear exits a rack is slightly different to the way two gears part. I unwittlingly cut a rack with an involute cutter, and I promise you, it does not work well.

A rack is just a gear with infinite radius. The same rules apply. It requires an involute shape like any gear, it is just that the involute surface is straight in this case.