Ball handles?

Balance, Tim. And really, if you crank real slow, and the thing doesn't slide too easily, you don't need that extra. However, a good machine will need it. And, a handwheel is good to have on a lathe because oftentimes two hands are used at once for better control. Say you need to turn up to a shoulder and are using an indicator as your guide. As you turn the handwheel and get close to the stopping point one hand turns while the other acts as a brake or drag. This method makes it much easier to stop exactly where you want. When turning that crank fast the balance will make thing go smoother. When making a facing cut two hands turning the crank will make the feed rate more even giving you a better finish. ERS

Note that the ball on the end without the crank is larger than either the center one or the one with the crank.

The center one can easily just be a cylinder, but is spherical for the sake of appearance.

The large one at the unused end is intended to match the mass of the small one plus the crank so vibration is less likely to turn the crank while your hand is elsewhere on the machine. Obviously, the counterweight could be a cube, or a cylinder or whatever, but appearance is one factor for it being spherical. The other is the avoidance of sharp edges and corners which could nick knuckles, especially when you are cranking rapidly (such as withdrawing a threading tool at the end of a pass).

Spoked handwheels are likely to have a bit of extra material opposite the handle to balance that as well. Smaller disc-form handwheels usually don't have counterbalance built in, as the handle is a fairly small bit of the total mass.

Good Luck. DoN.

Well... no concern here.... as it wears it might ease up a bit though.

With the carriage clamped in a vise and the vise grips cranking it back and forth, I could go reasonably fast given the friction. And it didn't wobble much at all (except at full extension, some 16" out). Balance doesn't seem to be an issue. And that's clamped at just the far end, not most of the carriage as on the ways. Leadscrew is a solid length of 3/8-16 standard threaded rod, mind you.

For slow cranking I can lever against the shoulder that attaches to the shaft, no problems there.

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

Ah! Very good point.

Ok, here's another... what's keeping me from brazing a few bits of steel to a nut and adding a set screw (or jamming it on with another nut)? Or more intracately, forging a piece of steel... hmmm........

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

An unbalanced crank imposes a sinusoidal "noise" torque proportional to the weight of the imbalance. This is superimposed over the controlled torque being applied by, say, your hand, which is hard enough to keep steady as it is. While this noise may be too small to matter on cruder machinery, it isn't zero, and it would show up in the quality of the work on finer equipment or tasks.

...

I didn't follow your comments very closely, but if you need nice spheres, consider snooker or pool or golf balls.

-jiw

Old PC trackballs are a cheap source of plastic spheres.

Craft stores sell wood spheres.

Tim, Consider this very carefully...If you replace the jam-nuts/vise-grip combination you will be inviting chaos into some other portion of your life. Your car, TV, stereo,or your computer will somehow become "Mechanically Disadvantaged" and require some kludge repair to function again. Your car will only start if you turn the wheel to the right lock and jam a screwdriver into the light switch. Your TV will only receive if you have 2 yards of foil on the antenna and YOU HAVE CABLE!!! Your stereo will only play C&W unless you duct-tape the input buttons together. You get the picture? Leave the vise-grip alone!!!

That's the idea, but I don't want to have to leave the house for anything. :^)

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

Nothing. Remember to try to shape it so you don't bark your knuckles as you are using it.

I would suggest that you do just that as a first pass, and when you have the lathe working set up a radius turning attachment and make your own ball knobs for a final pass. After all, you are using the machine to help build other parts of itself, so this is just another stage of the operation.

Best of luck, DoN.