Atlas Craftsman 10" 12" Lathe 2 Step Motor Pulley 5/8 bore . Part Number 9-428.

[anthonyc]

Atlas Craftsman 10" 12" Lathe 2 Step Motor Pulley 5/8 bore. Part Number 9-428.​

 

[Bi11Hudson]

My original Craftsman Lathe (101.27440) motor had a 1/2" shaft. When I replaced that motor with a Baldor "Farm Duty" motor, the 5/8 shaft had me stumped for a while. The low speed pulley was too small to overbore to 5/8". I'm not too particular about speeds, there are several points that allow adjustment of ranges. The "16 speeds" was as much a marketing ploy as it was useful. I ended up with a single stage pulley slightly larger than the low speed and slightly smaller than the high range pulley. But I fit the 5/8" shaft and used the larger sheave on the countershaft. The machine likes it fine. I did use a tachometer and built a new speed step table. Printed (large type) and hung above the machine. If I ever decided to sell the machine, it would go with the original motor, for which the pulley is at hand. So the speeds printed in the manual would apply. If I ever run into a situation where the higher speed range was necessary, it is a simple matter to move the pulley to align to the high range on the countershaft.

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[anthonyc]

Thank you for your input.
I did find the correct pulley but the price was out of my range. I purchased a step pulley 2", 3" and 4". I think that should do just fine. I may need to move the motor over a bit to align the pulley when changing speeds.

 

[wa5cab]

The OD's of the original 2-step pulleys (both shaft diameters) was 1.930" and 4.390". So the 2" and the 4" would come the closest to giving the original speeds. However, for the belt to match up to the original 2-step countershaft pulley, you will have to move something. As you will also have to move the motor closer to and farther from the countershaft (or use two belts maybe), you might consider drilling 2 sets of 4 holes and just move the motor.

 

[anthonyc]

Well the new Motor arrived today it has a slotted base right to left and the mount is slotted front to back.
There is plenty of adjustment.
Would you happen to know the proper diameters of the 2 step counter pully?
Im completely going through this unit....with a new look.

 

[wa5cab]

Sorta. The only drawing that we have is of 9-427, the 2-step countershaft pulley with the four cranked spokes. It was to be made from a casting and is found on almost all of the 3/8" bed machines. . The critical diameter dimensions are given as measured over two 7/16" diameter rods held in the grooves. Those are 7.763"/7.743" for the smaller groove and 9.420"/9.400" for the larger groove. However approximate dimensions are given for the actual physical OD's which are 7-1/2" and 9-5/64".. Those dimensions are given at the physical OD where the groove width is given as 1/2". The closest that you are likely to find are 7-1/2" and 9". And probably only on single-groove pulleys. Maybe you can find two that be machined and treated as one.

My Atlas 3996 12" has part number 560-060 for the 2-step counter shaft pulley. It is probably made from wrought plate. It would have been 10-427 had not the Clausing hands gotten the upper hand sometime in the mid 1950's (Atlas bought Clausing in 1949/1950).

 

[anthonyc]

Thank you . That is very helpful.
My machine was born on or around 04/10/1951.

 

[wa5cab]

Anthonyc,

To give a specific date like that, you must have either the original invoice or one of the four dates off of the two spindle bearings or ???. Which or what is it? Also, let us have the serial and model number.

 

[wa5cab]

Bi11Hudson,

When you originally started this thread, you stated that you had a motor pulley 9-428 and that there wasn't enough material to bore out to 5/8". I have a 10-428 motor pulley on my 3996 with a 5/8" bore and as far as I knew, the only difference is the ID. And maybe the set screw is shorter.

Or maybe my assumption is incorrect and the only difference between 9-428 and 10-428 isn't just the ID or bore. The only drawing that we have of 10-428 is one drawn by a member of the groups.io Atlas-Craftsman group. How about posting a large side-view photo of 9-428?

 

[anthonyc]

Craftsman / Atlas 101.07403 Ser 38948 04/10/1951.

Here is the photo of the pulley I sourced. Outside Diameter 2.0", 3.0", 4.0"