C3 Mini-Lathe Metalworking Beginners
7x12 mini-lathe - Cutting worm gears
Some remarks on cutting worm wheels and gears on a mini-lathe
It is possible to cut worm gears on a mini-lathe. However, the key factor to bear in mind is "Application". In the case below you can see I had a requirement to cut a worm wheel around the side of a rotating filter holder. This is not an application that requires extreme tolerances - any technique would get the job done.
If you want to cut a worm wheel and gear set for something extreme like a telescope mount, or lifting ore carts up a mineshaft, you probably will struggle with a mini-lathe. Whilst ore carts are a little beyond the range of a mini-lathe, it is possible to make 6 and 7 inch worm wheel and gear sets on the mini-lathe.
The basic principle is to have a worm gear (some kind of threaded rod) and a worm wheel - a disk of material which has the worm wheel teeth cut around its outer circumference. The teeth in the worm wheel must be cut using a tool. The tool is either made on the lathe, or a piece of threaded rod is used with a cut made in it - rather like one flute in a tap.
I find that cutting worm wheels with a regular tap is very difficult - for most low stress applications I just use some M6 threaded rod which has been modified to be a tool using a quick swipe with a dremel.
Finally, wheel and worm can be lapped using some metal polish.
Here are some pictures (worth perhaps a thousand works!) of me cutting the worm wheel gearing on a rotating filter holder using some threaded rod as a tool.
Making bigger disks is more of a challange - and the first challange is making the disk in the first place. See here for the biggest job you can turn on a mini-lathe.
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