This is a jack shaft I made for my lathe. I made nylon, or is it delrin, pulleys. The block of aluminum was milled to fit the motor and O rings for belts. The reduced speed allows for more torque which is necessary for turning harder materials like drill rod. I also dislike the variable speed foot switch. My foot usually slowly lifts and the RPM's slow down. I use a cheap router control from HF. Excuse the grainy photos. They were taken with my old Sony Mavica. I was too lazy to change cameras.
maybe I should have expanded my question a little....
I hope that anyone who has the desire to work with lathes, should know about pulleys and various sizes for changing speeds, but with the clock lathes I have seen rear solid mounted spindles that have a variety of sizes spaced out over a considerable distance.
With such a "selection" of pulleys I was wondering if it is typical to have special attachments that can be powered by a pulley? say maybe a "live" drill chuck in the tail stock?, a milling attachment? something exotic?
Otherwise, with a DC motor and a variable speed selector, wouldnt be much need for pulleys (of course your motor selection is such that even at lower speeds you still have sufficient torque).
Hi Fireguy, I have to add my voice - while I see other clockmakers run their watchmaker's lathes with just a motor and a drive belt, I think that it's important to use a countershaft (also called a jackshaft and a couple of other things) in your setup. The reason it's important is because it not only slows down your lathe but it also increases torque. Most watchmaker's lathe motors run several thousand RPM's, and the most effective work on your lathe happens when your spindle speed is somewhere between 500 RPM and 800 RPM, especially for hand turning with a graver. There are times that higher speed is required, like when cutting steel with a carbide graver.
On my countershaft, the motor drives a larger pulley. Next to the large pulley is another stepped pulley hand-turned to match my lathe's headstock pulley, but mounted in reversed direction. The two pulleys being the same diameters but reversed allows me to shift the drive belt from the left position, middle position and right position to give me 3:2, 1:1 & 2:3 ratios. Of course, there's always the three-step pulley on my motor shaft, as well as a small pulley adjacent to my large pulley on the countershaft - so there's plenty of choices. I have to say I'm very happy with my setup as I have it now.
As a final touch, it's not a good idea to leave tension on the headstock overnight, so I made the drivebelt on the headstock with plenty of slack. When I'm ready to run, I spin the headstock a few turns by hand to distribute residual spindle oil, and then use a magnetic-base-mounted idler pulley to take up the slack. I usually add two drops of spindle oil to each oil cup every other day.