0.2 module worm gears

[bungler51]

Hi all.I need some 0.2 module worm gears.

I know I can buy them from Germany,but apart from the cost,and the shipping time,it would be much more convenient if I could make them myself.

I know that most model engineers work in imperial,but I'll throw it out there anyway.

I have Sieg a 7x12 mini lathe,and wondered if anyone can work out how to set it up to cut the 0.2 module 20 degree worm on,say 3-3.2mm brass rod.

I have no idea how to work out pitches,or required gearing to achieve the 0.2 module,or even if it's possible on such a cheap(ish) lathe.

The gear would be easier,as I have watched several videos on you tube,showing the use of a tap to cut a gear.

But again i have no idea what size tap i would need to use.

The end game is a total self-built gear train,with the worm drive as a 1st stage,to be used in a 1/87th scale truck.

The motors used are 6mm pager motors,with a .7mm-1mm shaft.

Thanks for any pointers anyone could give.

Hans.

[barlowworks]

Hi Hans

I would think that given the number of small gears available from the trade you would be better off buying them. But if you really want to make your own, there must be a YouTube video out there somewhere. Or someone on here may know. Either way good luck.

Mike

Also try putting a comment on the general chat section, a lot more people read that. 

[Jim]

I'm a bit late to this thread but if it's any help I made worm and wheel gears for my O gauge locos using suitable taps and matching dies.

The die cut the worm and the tap was used to hob the the wheel which was a very simple process. The tap was held in the lathe chuck and a blank disc of brass on peg so it was free to rotate was fed onto the tap rotating in the lathe. Gently feeding the blank in the tap started cutting a thread and so made the blank rotate. The tap kept cutting away as the blank was gently fed in until a full set of teeth were cut round the perimeter of the blank which matched the thread cut with the die.

It sounds more complex trying to describe it but it is a very simple process that doesn't require any expensive tooling.

Jim.