What to do with 58 tooth worm wheels?

[duncanbojangles]

So, I won an auction on eBay for a couple of big brass/bronze worm wheels. They're about 3.25" in diameter, being about 11/16" wide at the teeth, and have 3/16" deep bosses on either side. Really lovely, really, and got 'em for quite a deal. One looks new and the other has a bit of wear.

The only problem is, they're both 58 teeth! What in the world am I gonna use 58 tooth worm wheels for? Silly me, I didn't count the teeth in the photos in the eBay description, and the description didn't specify the number of teeth either.

I was really hoping to use them for a rotary table and a dividing head, but 58 divides into 360 so oddly. So does anyone out there have a good idea or use for 58 tooth worm wheels? The deal was just too good not to make something of them.


DSCN1319 by duncanbojangles, on Flickr

DSCN1317 by duncanbojangles, on Flickr

(The numbers in the pictures were put there by me as I counted, and triple checked my counts for both worm wheels)

 

[RonGinger]

Sure make the rotary table and make an Arduino controller for it. The gear ratio is simply a number in the program, it does not have to be a nice round number. All it means is the program will have to output some strange number of steps for each degree, but thats OK, microprocessors dont care what the answer is, they just do the right thing.

 

[mcostello]

Garden tiller replacement gears.

 

[deverett]

Good basis for a couple of flywheels!

Dave
The Emerald Isle

 

[gus]

Was planning to hobb a 72t worm gear for my latest RT and ended with 71t. Hobbing with spiral tap on the lathe does guarantee what you plan for. Just been told I must gash the worm gear with 72 slots but my RT with 71t cannot give this gash numbers. Now planning beg/borrow /steal 72 t spur gear. May also try using a big disc and protractor to get 5 degree incremental graduations.
RT done with 71 T worm wheel and a hand wheel giving me 5.07042254 degrees.:hDe::hDe:

 

[duncanbojangles]

Was planning to hobb a 72t worm gear for my latest RT and ended with 71t. Hobbing with spiral tap on the lathe does guarantee what you plan for. Just been told I must gash the worm gear with 72 slots but my RT with 71t cannot give this gash numbers. Now planning beg/borrow /steal 72 t spur gear. May also try using a big disc and protractor to get 5 degree incremental graduations.
RT done with 71 T worm wheel and a hand wheel giving me 5.07042254 degrees.:hDe::hDe:

Haha Gus, I've seen so many examples of 41 tooth worm gears and 71 tooth worm gears online that I was scared to try hobbing a worm wheel with a tap! That's why I looked for a good deal on one on eBay. It looks like I'll be taking my lead from your example and hobbing my own worm wheels from now on. I've got all the taps I could ever need to borrow from work.

 

[gus]

Haha Gus, I've seen so many examples of 41 tooth worm gears and 71 tooth worm gears online that I was scared to try hobbing a worm wheel with a tap! That's why I looked for a good deal on one on eBay. It looks like I'll be taking my lead from your example and hobbing my own worm wheels from now on. I've got all the taps I could ever need to borrow from work.

Hi Duncan,

It was so easy and fast to use spiral taps to hob worm gears and sell to some guys thru e-bay .Ha ha.
While hob the 71T and 76T worm gear,I was so happy and amazed that this process could turn gears so fast. True .You won't end up with 1/2 tooth.
Now dreaming of making DIY hobbing machine. Hard to go back using gear cutter to cut tooth by tooth.:wall:

 

[barnesrickw]

I saw the tap method and wondered if you had to calculate the circumference of the gear to avoid a half tooth. Does this not need to be done?


Sent from my iPad using Model Engines

 

[gus]

I saw the tap method and wondered if you had to calculate the circumference of the gear to avoid a half tooth. Does this not need to be done?


Sent from my iPad using Model Engines

Been advised by BaronJ for best guarantee,pre-cut 72 gash to get 72T.This was what Baron did in his thread and I missed it.
Planning to do this soon I as get get from Burma Deep Sea Fishing end Feb .

Now looking for a sure-fire method to make a 72 direct index plate.

 

[OrangeAlpine]

I was able to hob 72 teeth, using a shop made hob. Calculating the correct blank diameter proved impossible. Had to make a couple of gears before getting the desired result. The results seemed to be technique sensitive. In other words, make it the same way each try, changing only the blank diamater and the results will be predictable. Made mine out of aluminum.

I think I have a thread describing the process.

Bill