Ignoramus32374 wrote:
I would also like to make a rock tumbler, like another poster. My plan
is as follows.

I will use a used tire as the rotating vessel. I grew fond of used
tires after my generator project.

The tire will be bolted to a large plywood ring that will have a hole
larger than the internal diameter of the tire, just enough to go a
little bit over the widest point of the tire.

There will be a board screwed to plywood and serving as a "diameter"
of the plywood ring.

I'd say the ouside of a tire might make a good surface to run directly on a motor shaft of some sort, letting you skip all the gears and nonsense. Why does this need to complicated?




There is going to be a horizontal shaft, mounted in bearings. (see
below). The shaft will be made either from a steel pipe nipple, with
flanges on both ends, or from a solid 3/4" diameter piece that I
already own. On one side, a sprocket will be bolted to the flange. On
another, there will be an adaptre plate to attach the "diameter" board
securely, but it will be removable for cleaning purposes.

The sprocket will connect via chain to a 3/4 HP 60 RPM gearmotor with
a keyed shaft and another (smaller) sprocket. My friend will give me
that gearmotor (I gave it to him 3 years ago, but he did not use it).

My expense will be sprockets, nipples and the shaft (maybe).

My question is about bearings. I have a variety of bearings, about
100-150 lbs of bearings. I have some sealed bearings, some needle
bearings 1 1/8" ID. Huge stuff for tractors and tanks, tiny ones etc.

I also have something I like, spherical bearings 3/4" ID. They are not
pillow blocks because they do not have a "base" to be screwed to
something. Nevertheless, they are nice because they can survive
misalignment. (I also have some 1/2" ID spherical ones, but I need a
bigger shaft).

My misgiving about them is that I am not sure what shaft to use. I
have a solid steel 3/4" shaft. But how would I mount a sprocket on one
side, and a plate holding the wheel, on another? I can easily drill
and tap a coaxial hole on both sides. But I have great doubts that the
bolt's tension would be enough to hold it during days of operation. I
do not have a welder.

I could try to thread both ends on my lathe, but I expect this to
become a pathetic failure. And I do not think that there will be a
suitable NPT flange at my home improvement store (although I am not
sure).

I can probably drill smaller parallel holes and tap them and put in
little 8-24 screws or some such.

i