Turntable?

Some turntables fed off a variable frequency power amp. The frequencies just jumped, instead of slewing. Other than a servo unit, I think a simple DC motor with a gear or belt drive would do it.

greg

That's what I thought, but I was hoping someone somewhere sold such an item cheaply, probably for other uses.

The stirrer plates used in labs are too fast and not enough torque. Look in the Jameco catalog under gearmotors. You shold be able to grab a large diameter hub somewhere.

greg

A UK political party

Go to a hobby shop and check out the selection of Tamiya gearbox kits. There might be something there of interest.

Potter's wheel?

Weld positioner?

Have Fun! Rich

All, or part of a lathe?

Tam

Too expensive, and too big. It only needs to be hand size.

Possibly potter's wheel. I'll check prices, but need a speed controller. Maybe the model shop gearbox the netzero guy suggested.

On a sunny day (Sat, 01 Nov 2008 00:00:55 GMT) it happened Rich Grise wrote in :

Just put y'r car on the side, use a rear wheel.

That's 30 to 600 rpm. Chuck it in a variable speed hand drill, the kind where the trigger pull controls speed and it has a set screw on the trigger to make it reproducible, or take a small dc muffin fan and run it off a variable dc supply (cut off the blades if they bother you). We used the muffin fan idea back in school, with a small glass plate glued on the hub to put grinding paste on, to polish the ends of glass fibers. If you need faster chuck it into a dremel tool, but they go up to 6-12000 rpm so the low end speed control is very coarse.

----- Regards, Carl Ijames

org/- A UK political party

Option-1: Gerbils. ? Plus, a supply of other Gerbils injected with varying doses of testosterone. ?

Sorry. Let me put my weekend serious cap on: One of my standup drill presses uses a two-pulley system (multiple diameters). Adjusting the belts changes the speed and torque. Also, what about a microwave oven turntable? Can you do anything with that?

-mpm

Cheap mains fan with an added speed controller. Would a dimmer switch work, or is the load too inductive? Maybe an auto transformer?

UK

Too slow probably. And my oven is still working, despite all the graunching noises from the turntable.

DC gear motor salvaged from an old (large) photocopier - stick a platter of some sort directly on the output shaft. Run it from your bench supply - worked well for me!

...

Microwave ovens are free, if you know where to dumpster-dive. ;-)

Cheers! Rich

I have several ideas based around variable speed hobby motor / controller combinations.