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Seastar
12-03-2006, 02:46 PM
I bought a 1942 model 200 10 inch logan and have rebuilt it so that it works very well.
As is usual with lathes this old, I am missing about half of the change gears.
They don't show up too often on e-bay and I wonder if anyone knows the specs for them (pitch angle etc.) so that I could try to buy some from Boston Gear or someone else.
Logan has them but the prices are extreme.
One back gear that I needed cost me almost $100 from Logan and I need about a dozen change gears.
Any input is welcome.
Bill

gzig5
12-03-2006, 03:43 PM
Bill,
I can't help you with the Logan gear spec, but if no one else can I have a suggestion. Call around and find a shop the specializes in gearcutting and see if they will meaure one of your existing gears. Might cost a couple bucks or a box of doghnuts, but you will then know what to scrounge for.
Greg

vmil3
12-03-2006, 03:43 PM
Lathes built back when Logan's were will have a 14-1/2 deg pressure angle, you state you have half of the change gears, select one, preferably with an even numbered tooth count. Measure th O.D. of the gear, count the number of teeth and add 2 to the number of teeth

Divide
the total number of teeth +2
---------------------------- =gear tooth pitch
by the O.D. of the gear

eg; gear 36 tooth O.D.=2.375"

36 teeth+ 2
------------------=
2.375
38
----- = 16 = this gear has 16DP teeth
2.375

Ok.

J Tiers
12-03-2006, 04:05 PM
A set of change gears will cost you more than the whole lathe if bought new. Much as I like to support Logan, I bought ONE and then bought used, flat uneconomical otherwise.

CAtruckman@aol.com usually has them How does $5 or $10 look?

No I am NOT him, just a satisfied customer.

They are 16 DP, 14.5 PA.

pntrbl
12-03-2006, 04:06 PM
There's a Logan Lathe list at Yahoo I frequent. Not real busy but there's some real knowledgable foks there. They was talking about boring the ID of a bullgear the other day to get it to fit a different model.

I'd give ya link but my confuser skills aren't that good.

SP

Norman Warfield
12-05-2006, 06:54 AM
Did you find your gears you needed? I have a Ward's Powercraft lathe built by Logan, all the gears in it are replaceable by Boston stock items at 14-1/2 degrees.

Greg Menke
12-05-2006, 09:07 AM
Once you establish the pressure angle and DP, you might consider buying new gears from a place like Martin Sprocket

http://www.martinsprocket.com/

they have an extensive online catalog & their prices are quite reasonable. If you find matching gears then you can order an assortment, then bore them out and put in keyways as required.

Greg

lazlo
12-06-2006, 01:05 AM
They are 16 DP, 14.5 PA.

Most manual American lathes (South Bend, Logan, Monarch, Clausing,...) are 16 DP, 14.5 PA, with the notable exception of Hardinge, which uses a wacky 22 DP, 20 pitch angle with a stub tooth form.

So you might be able to find an American change gear with the right number of teeth, and re-cut the bore and keyway to match your machine.