I'd rather fight than switch! (changing speeds on belt driven lathe)

I've also utilized the Trexon Tachulator. It's a great piece of equipment for any metalworking machine.

When you use a continuously variable speed drive, it's great to know the actual speed, and with the Tachulator, you can also see the surface feet per minute for the diameter of workpiece (or rotating tool) with one setting.

Here are some descriptive pages of an enclosure I made for the Tachulator, with pichers 'n stuff

I've had an idea for reducing a machine's speed by using a dual-shaft motor (which could be a 1750 RPM motor), but I haven't built one yet.

What I have been thinking of is a jackshaft-type device, but one that takes up far less space, since it utilizes the second motor shaft.

With many common motor applications, the motor pulley is in line with the machine's driven (spindle or arbor) pulley. By placing a shaft directly over the dual shaft motor, speed reduction pulleys can be placed on the second side, which could reduce the speed of the shaft to about 1/2, 1/3 or maybe 1/4 speed (only one choice). Toothed gearbelt-timing belt is probably a worthwhile consideration on the reduction side (to eliminate slippage).

Then, back at the original working end of the motor, another drive pulley is placed in close proximity to the full speed motor pulley.

If the placement of the reduced-speed pulley is in the same radial arc from the spindle, only one size of drive belt would be required. If an over-center latch (or toggle clamp-type, quick setting device) is incorporated in the belt tensioning (pivoting motor mounting plate, for example), changing speeds could be done very quickly.

For some applications, this reduction assembly could be fairly compact. Fabrication of a couple of belt guards to complete the installation should keep debris off the belts, and keep the operator safe from injury, preventing contact with the belts.

WB ......... metalworking projects

That's a good idea. The usual problem with adding a jack shaft is the space required in the belt "alley". But your idea doesn't need a dual (ended) shaft. A single shaft motor could just be turned over to do the same thing (reversing the rotation). In fact, I'm going to think about doing that, thanks.

Bob