Custom Gears for BSC threads on Craftsman 101 Lathe?

[Unmarked Bill]

Maybe this is too much of a longshot, and maybe this is one of those questions that someone pops in with periodically, I did a search and couldn't find anything.

My question is, is there anyone on here (or elsewhere) who can make gears to run on my Craftsman 101.21200 lathe that will cut 26 tpi, 32tpi, and 40 tpi? I have seen shop-made gearsets for these lathes on here, I think, maybe it's just my imagination?

Thanks in advance for any help!

 

[Unmarked Bill]

Change Gears bump

 

[Jim Johnstone]

I assume you don't know the specifics of the gears you need? Ie number of teeth, pressure angle, module etc? If you can source all the gear specifics, any gear cutter could bang them out with ease, but they need to know what to cut.

 

[tombell572]

As Jim said above, you must know the gear characteristics first. Then check Boston or Martin gear and Ebay for available sizes. You my need to machine off a hub, change a bore size or cut a keyway. I restore Brit. bikes and cut BSC (CEI) threads on my Sheldon lathe, 26 tpi being the most common on these bikes-not an uncommon thread.

Tom B.

 

[Jim Johnstone]

http://bbs.homeshopmachinist.net/showthread.php?t=62188

Just found this thread on a machinist forum, specifically about craftsman/atlas change gears.

 

[Unmarked Bill]

Thanks! I dont know how to calculate gearing for tpi, but I guess it can't be too impossible.

 

[Unmarked Bill]

Aaaaand there's a calculator online. My lathe has a 16tpi lead screw, so this should be the recipe?

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[tombell572]

Bill, metal lathes usually have a tag or plate attached to the headstock area with a table of gears required for the various thread tip's the lathe will cut. I'm not familiar with your machine but is yours missing?

Tom B.

 

[Unmarked Bill]

Theres a chart in the manual but it doesnt say for 26tpi or any cycke threads.