thumbwheel potmeter for left-right usage

[Joerg]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

The Panasonic EVLHFA seems to go in the right direction but no specs on
the teeth and the data sheets hardly ever say much about that.
Definitely not about the material strength for geared usage.
http://www.panasonic.com/industrial/components/pdf/aok0000ce3.pdf

 

[martin griffith]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

The Panasonic EVLHFA seems to go in the right direction but no specs on
the teeth and the data sheets hardly ever say much about that.
Definitely not about the material strength for geared usage.
http://www.panasonic.com/industrial/components/pdf/aok0000ce3.pdf

Maybe Alps
http://potentiometers.com/alps_position.cfm
and fit your own wheel

Pity about the 1200MOQ


martin

 

[Brian]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

The Panasonic EVLHFA seems to go in the right direction but no specs on
the teeth and the data sheets hardly ever say much about that.
Definitely not about the material strength for geared usage.
http://www.panasonic.com/industrial/components/pdf/aok0000ce3.pdf

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

 

[Joerg]

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.

 

[Jamie]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

The Panasonic EVLHFA seems to go in the right direction but no specs on
the teeth and the data sheets hardly ever say much about that.
Definitely not about the material strength for geared usage.
http://www.panasonic.com/industrial/components/pdf/aok0000ce3.pdf

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.

 

[Joerg]

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?

 

[Jamie]

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.

http://www.sdp-si.com/eStore/CoverPg/Gears.htm

 

[Joerg]

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

http://www.sdp-si.com/eStore/CoverPg/Gears.htm

Thanks. They sure got a lot of gears.

 

[Brian]

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.

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.

 

[Chris Jones]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

The Panasonic EVLHFA seems to go in the right direction but no specs on
the teeth and the data sheets hardly ever say much about that.
Definitely not about the material strength for geared usage.
http://www.panasonic.com/industrial/components/pdf/aok0000ce3.pdf

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

 

[[email protected]]

... The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

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.

 

[Joerg]

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.

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.

 

[Joerg]

Joerg wrote:




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.

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!

 

[Joerg]

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).

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.

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

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.

 

[me]

Been through the usual channels like Digikey. Is there a thumb

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.

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...

 

[Joerg]

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...

That would make the pot turn opposite ways.

 

[me]

That would make the pot turn opposite ways.

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...

 

[jasen]

Hello Folks,

Been through the usual channels like Digikey. Is there a thumb wheel
potmeter that has coarse and strong enough "teeth" so an idler wheel (or
second pot of same type) can be mounted next to it so the wheels mesh?

Reason is a project coming up where a device needs to be controllable by
right- and left-handed folks. Kind of like a remote. The potmeter wheels
coming out the sides of the remote need to go in the same direction for
both. IOW "forward" for "more".

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.

 

[jasen]

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.

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

 

[jasen]

me wrote:

That would make the pot turn opposite ways.

What does "forwards" mean in your original question?


Bye.
Jasen