thumbwheel potmeter for left-right usage

Maybe Alps

Pity about the 1200MOQ

martin

Mounting one on the opposite side will make it rotate in the other direction.

That's exactly what we want. Assume one of them is just a dummy potmeter. Then when one sticks out the left side and the other to the right the turning direction of the active potmeter when you move the thumb forward will become the same.

We use mini flat gears for things like that. With gears, you won't have any problems with slippage and position falling out of place.

If it's not confidential, where do you get flat gears that fit onto potmeter shafts?

we buy gears were ever we can find them.. here's a place you can look at gears.

Thanks. They sure got a lot of gears.

I wasn't very clear on that. I meant that if you mount on on the left side on the top of the pcb and one on the right side on the bottom of the PB, they will both adjust in a forward/backward motion the same.

Does it really need to be a mechanical potentiometer? If you happen to already have a microcontroller in this thing, and if you were to put in two quadrature encoders (e.g. the cheap ones used in the scroll wheel of a mouse, which seem to be mechanical switches even in my optical mouse, so no LED power drain), then you could make the value which is being adjusted respond to rotation of either encoder in some very easy software. You could even use the result to control a "digital potentiometer" if that is what you need.

Chris

With a largeish single wheel, consider shifting or pivoting the mechanism so it only protrudes from one side at a time. A DPDT switch that responds to the pivot or shift motion can change the potentiometer connections (or use a simple microswitch and some analog-switch elements, or even software).

Meshing of gears seems so easy, but keeping axles parallel requires some complex molding or machining.

Yes. But I want to mount them on the same side and have the teeth mesh. The wheel of the left pot would then come out on the left side of the enclosure, the pot on the right would come out the other. You could then even hook up both pots in parallel with the polarities reversed, for more wiper reliability through redundance.

Well, it's all in good old analog right now. Probably will be an ASIC some day since uC with next to nothing in power consumption are a bit too expensive. But the whole encoder enchilada would have to be as cheap as two pots.

Right now it's up/down keys plus digital potmeter but the client prefers a "real" potmeter with tactile and optical feedback which I can understand. I was very happy when I saw that the new laptop I ordered will arrive with a real potmeter for the volume. Back to the roots. Nice!

I've talked about such a scheme with the client but this means lots of mechanics. Mechanical parts and switches have a tendency to increase DOA rates and field failures.

We do have access to a good rapid prototyping shop so we can test out what would work. The thumb wheels of potmeters you can buy often have teeth that are too small to do this reliably. We can tolerate quite some slack so coarse teeth plus loose tolerances would work. Pretty much like it is done in the "Fischer Technik" experimenters kits for youngsters (don't know if those ever made it to the US market). With these you can assemble all kinds of complicated gearboxes and they take a heck of abuse. Have to, because it's for pre-school kids AFAIR.

How about a central pot with a gear on it and geared wheels on either side? So turning either one turns the pot and the other wheel...

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That would make the pot turn opposite ways.

Joerg wrote in news:Rmklh.26414$ snipped-for-privacy@newssvr21.news.prodigy.net:

no, make one gear smaller and have a second gear on it. I'll leave the ratios to you.

Another option is the dreaded dial cord...

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Use an open trimpot and put a shaft through the middle. puta a control knob each end of the shaft. if that's not right I don't understand your description of the problem.

Do that and turning the left wheel forwards will turn the right one backward. (IE both will turn counter-clockwise).

Your second paragraph basically asks for a solid axle with knobs each end.

Bye. Jasen

What does "forwards" mean in your original question?

Bye. Jasen