Lathemaster Speed Reduction Pulley

Bob Bertrand promised me I could get one of the low range speed reducers for my 8x14 lathe. He has received the first batch awhile back and is now advertising them on his web site. Lathemaster Metalworking Tools This will fit both the 8x14 and the 9x30 machines.

Mine showed up a few weeks ago. I was busy getting the shop back into shape so installation had to wait. I now have it installed so here is what it takes to make the conversion.

This is the new Pulley. That is a ball bearing at the pointy end. This device is a planetary reduction gear with a 2:1 speed change. All built inside of the belt drive step pulley.

You just know I have to take everything apart! Here is what it looks like on the inside. Just take off the E-Clip. This edition is very clean and didn't require cleaning and re-packing.

This is the standard jack shaft (idler) pulley arrangement. This belt arrangement is currently set for the speed I run the most. This is low speed on the high range. It doesn't seem to make any difference if the belt tension runs on the inside or outside of the belt.

The nuts for the jack shaft can only be accessed by opening the electrical covers. It is double nutted so this tear down must be done.

With the two sheaves side by side you can readily see the difference. Note the shaft bearing mounted on the front of the speed reducer. Both bearings in the speed reducer are ball type.

There is a significant shoulder height difference which affects the standoff distance from the mounting deck (or plate). The new pulley on the left mounts much closer to the deck than my original pulley.

This just proves that there are changes during manufacture that may make your machine different from others and mine. We all need to fine tune our machines for things like alignment.

The belt still has some slight alignment variations between all the speeds. This has always been there and I haven't suffered any belt wear problems. The reason for the misalignment is a slight differences on all three pulley 3-step groove spacings. The three pulleys are not identical height.

I bought some 17mm washers to shim out the new pulley. However, I had done some previous shimming on the back plate when the lathe was new to get the original sheaves aligned. I discovered when I removed those shims, the lower deck height on the new speed reducer was all right. That's nice!

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Note the very low speed (about 62 RPM) useful for tasks like thread cutting.

I have the tensioner on the inside of the belt here. V-Belts are designed to drive on the sides, not the top and bottom. The benefit I can think of for the inside position is that it doesn't flex the backing (of the belt) in a reverse direction.

This is a trick shot with me trying to get the lathe started from a dead stop. With the capacitor start, capacitor run motor, the start up is almost instantaneous. Keep fingers away!

This addition to the lathe looks like it will be useful for the slow speed work. The torque is greatly raised as the speed is reduced. The installation is not difficult once I sorted out the alignments. It looks like it will not be difficult to return the lower speeds back to their original drive if that is desired.

This may not be a conversion for everyone but it is sure an easy compact way to achieve very low speed operation without a complete gear change. One last note is that the planetary gearing causes a reversal in the rotation direction of the speed reducer. Just switch the motor direction switch to reverse and all is fine.