Homemade lathe refinements
Easier tool rest adjustmentsThe first change was to make a handle for the nut so I wouldn't need a wrench to adjust the tool rest. I started by drilling a hole the same diameter as the nut is flat-to-flat, then marked the outline of the nut around the hole.
Reducing headstock rattleThe lathe made a rattling sound when it ran. I realized this came from the spacers that I made for each side of the pulley. They were loose and rattled as they turned.
They were tricky to get right and the shaft still had some lateral play even with them, so I figured they weren't the best solution. They also prevent me from checking if the shaft is hot, which, with wooden bearings, I want to be able to check.
First I drilled the screw holes through it, then cut a block in half, then clamped the two halves together and drilled the hole on the line between the two.
Tailstock adjustmentI wanted a better way to move the shaft on the tailstock forward. So far, I nudged it tighter by tapping the back with a mallet. But with only friction holding it in place, I figured there is risk of it slipping back unexpectedly and releasing the workpiece. That would be bad.
My first idea was to put a pin (a nail) through the shaft, and then use spacer blocks and wedges to drive the shaft forward. But I realized, if the wedge is relatively high up (as shown), with vibrations, the wedge could tip forward and then fall out. This would allow the tailstock shaft to move back suddenly. Not safe.
But that approach also has its hazards. With a lot of friction on the shaft, the knob could work itself loose without loosening the workpiece, and the shaft could then jump back unexpectedly. Also unsafe.
I thought I couldn't really do that with the threaded rod because the threads would chew up the bearings. But I gave it a try. I made a block to attach to the end of the threaded rod to mate with the drive center on the headstock. I also made a sacrificial bearing block, which I clamped to the tailstock. Two nuts on the threaded rod against the bearing block keep it pressed against the headstock.
The hole in my crank disk was also a bit smaller than the threaded rod. I screwed it on until the threaded rod was flush with the disk and the slots aligned. I screwed a small wood screw between the keyway notches to lock it in place.
Motor mountThe final improvement was to find a good way to mount the motor. I wanted to be able to move the motor side-to-side and near and far from the lathe so I could use all possible combinations of pulleys.
The belt I'm using is perhaps a bit long for the job, but the advantage is that it keeps the motor further away from the shavings coming off the lathe.
The motor is already on its own piece of plywood (from when I used it to motorize the apple grinder a few years ago).
The L shaped rails allow the motor to move forwards and back. For side-to-side adjustment, I figured it would be best to mortise them into another piece of wood, which I could adjust side-to-side along the back of the lathe.
My slot mortiser would be ideal for cutting mortises into the board, but I didn't want this project to be dependent on my custom machines. So I made a series of cuts on the table saw to cut a sort of "open mortise" (like here).
I'm sure people will suggest to just put the motor on a hinge so the motor's weight can tension the belt.
The problem with that is that V-belts are always prone to vibration. If the motor is hanging off the belt, that will cause the motor to shake. For every reaction there is an equal and opposite reaction, so shaking of the heavy motor will cause the whole lathe to shake. Not good.
But with the motor fixed to the lathe, the V-belt can only shake itself. The V-belt is much lighter than the motor, so it causes much less vibration in the lathe as a whole.
Beri's homemade lathe
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