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1918 16" X 72" ???s

mad mac

Plastic
Joined
Jun 29, 2004
Location
lambertville, MI. USA
I was just hunting around for some anserws about getting some change gears for my 16" southbend lathe weather I should look for the origanals or try to get some from a gear vendor. I also am looking for somthing I can use to retrofit the secondary drive shives on rather than build a complete swing frame. I am new to the board and have only looked around a little.
 
Welcome to the board! You and I have the same problem; a 1918 South Bend without all the change gears, mine being a 13" x 60" bed.

Assuming you have SOME gears, and you probably have at least the ones on the tumble-reverse, figure out what Diametrical Pitch (DP) you require. (The definition of Diametrical Pitch is in almost every machinist's handbook I've ever browsed through.)

Measure the width of the gears, the diameter of the center hole, and the size of the keyway, where applicable. (Note that gears used only as "idlers" don't need a keyway.)

Look at the gear table to make up a list of what gears you need. (On my lathe, this is a brass plate on the left leg.) Note that some gears are used only on obscure threads; I don't need the gear that is used only to cut 30 tpi. (God only knows why that one is included in the table!)

So, now you have a list of what you want, and can send this out to whatever sources you may wish to try. You should keep a copy in your wallet, too - you never know when you might run across a tub full of gears at at Flea Market.

Regarding the drive, a previous owner of my lathe made up a pretty spiffy frame to hold up a jackshaft with a four-step flat belt sheeve about 10" above the spindle. The c-frame (face-mounted) motor is on the back of this frame. The frame clamps securely to the Vee-ways. It is a stout weldment made of 1/4" plate with a stiffening "web". First picture at http://www.morrisconservatory.com/bbryan/jr/
(Ignore the erroneous id as a SBL Series O - it's a Model 34, traced via the serial number ledger at LeBlond to Sept 12th, 1918.)

My research indicates that most pre-1920 SBL's were painted black at the factory, with any color available if so ordered.

J.R.R.
 
Boston Gear is a source of change gears in several diametral pitches (DP) and pressure angles (PA).

Most American lathes use 16 DP 14-1/2 PA, but Hardinge uses 22 DP 20 PA.

For some DPs, Boston Gear even has a 127 tooth change gear, so you can make a metric transposer.
 
Have several 16DP 14 1/2 P.A. gears if someone needs them. Many years ago my 13 X 5 SB (possibly Model N?) has this pitch and P.A.

Also have the 1930/31 Model "N" catalog sheets.

John Oder

Houston
 
Ryobiguy,

Would you care to expound upon the picture entitled "grinding1", please??? Looks like the result of a hideous accident with a toolpost grinder. Does the compound still work "well enough" for the type of work you undertake? Were you able to repair any of this?

Sheesh, looks like a good part of the acme screw and the nut are worn away!

JRR
 
i have a 13 x 5 foot lathe if someone is interested in purchasing it. ive used it and everything works...its not worn out either. has quick change for threads too. was built in 1929. i purchased it to work on rifle barrels and couldnt pass up a good deal that it was.
 








 
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