Saturday, 10 January 2009
Cutting worm gears on a Lathe
Here is the finished worm gear holder with a worm gear blank in the holder and a finished worm gear on top for comparison. The cutter is a standard M3 Tap.
Note the 1.5mm PTFE disk under the worm gear blank (3mm thick) this is to centre the blank to the cutter and to support the gear during cutting whilst helping the gear to turn on the pin.
The pin is just a piece of axle with a coupling sleeve on to stop it falling through the gear holder.
I marked a line on each blank to show when it had done a full turn and with the RPM of the lathe set to about 200, advanced the gear holder into the cutter 0.05 mm per turn of the gear.
It could probably have been done quicker but I was'nt in a rush, the job worked perfectly and the cutter never broke.