Hi Jerry,
This has turned into a good thread. Thanks much.
Would you be willing to give some details of the center pulley shaft in the drill press post? Did you machine an insert? Bearings?
Sure, no problem! I ordered a piece of solid aluminum billet from Ebay, just a few thousandths larger than the inside diameter of the hole in the main post of tthe drill press and made it about 3" long between the bearings. I machined it to be a close slip fit into the post, then drilled and tapped the post for a couple of Allen head setscrews to keep it in place.
Next step- - - -center-drill the billet about 1/8" larger than the shaft I intended to run, (5/8") to match the ID of the 4-step pulley which I also bought on Ebay. I bought two 5/8" ID sealed ball bearings (Ebay again!) and counterbored the ends of the billet to be a snug slip fit for the OD of the bearings. A 5/8" shaft collar on each end secures the bearings into the counterbores, and a couple of drops of green LocTite keeps the outside races of the bearings from spinning in the aluminum. The shaft and support is secured into the post with the setscrews, and the pulley is installed in the proper direction to allow four different spindle speeds by moving the belt up and down. a belt about 1" longer than the pulley spacing is used, and the spring-loaded idler tightens it so it can pull without slippage. A second short belt goes from the motor to the center pulley. For every pulley position of the belt from the drive motor, there's 3 remaining pulley sheaves from the idler to the spindle, resulting in 12 speed options total.
When I get the low-speed motor into operation with the 1-way drive, there will be a total of 24 speeds available. The high-speed motor becomes an idler shaft when the low-speed motor is pulling. The Sprag clutch prevents the low speed motor from overspeeding when the main motor is the source of power.
Jerry
