# Thumb Wheel Potentiometer

I know that thumb wheel potentiometers are an outdated technology, everything is moving to rotary encoders. The problem I have is that my company has a large number of legacy products. We have designed rotary encoders into most of our designs but have a few very low volume products that wouldn't be worth a complete redesign. Here is the datasheet for the component currently used(its the 3rd on the datasheet). If anyone knows where to find something similar that would be great. I am also open to other alternatives and ideas anyone may have that would not require a complete redesign. I would like to simply be able to just update the footprint on the PCB to fit a new potentiometer

Note: I proposed the possibility of a knob protruding from the side of the product to control volume but that idea didn't go over very well, the thumb wheel is preferred.

Note: some specs are 10k, single turn, about 12.7mm (0.5") diameter

Discontinuation Notice

-
You haven't said why you don't want to use what is currently designed in. Are you having trouble sourcing that part? –  lyndon Nov 14 '12 at 13:45
I apologize. Yes that part is discontinued and very hard to find for our buyer. –  Brandon Bailey Nov 14 '12 at 13:50
Thumbwheel pots seem to be available from SparkFun, Digikey and Mouser. The latter two have various sizes and footprints listed. Is there a specific set of constraints apart from the 10k, single turn, and 12.7mm diameter? Also, could you please share a photo of how the product looks from the thumbwheel side of the enclosure? Alternatives may come to mind. –  Anindo Ghosh Nov 14 '12 at 13:57
Updated to show a picture of the device. –  Brandon Bailey Nov 15 '12 at 19:34

You say this is a low volume product. Therefore, just do one last lifetime buy. Even if you could find a drop in replacement, that would likely go obsolete soon too for the same reason. Doing a single lifetime buy will likely be cheaper than the engineering effort to find and then deal with parts that are not quite the same.

-
There are sources of surplus stock at premium prices. Alternatively you can research and qualify a made in china solution. i.stack.imgur.com/VUPSk.jpg –  Tony Stewart Nov 14 '12 at 18:47
@Rich: But why not just buy all you're going to need from the existing source before it goes away? That usually doesn't cost extra, other than the tied up capital in the inventory. However, the OP said this was a "low volume" product, so that would be minimal. –  Olin Lathrop Nov 14 '12 at 19:09
If possible yes, but my research it is already non-stock in all franchise disti's and factory. So broker forums will find it or buy at your own risk a replacement. Broker costs will probably be small qty for few hundred $or 1K at$1 new & NRE costs either way last time buy period was overdue. –  Tony Stewart Nov 14 '12 at 19:14
Lifetime buy has been considered but as of now we have not located a source with stock. It does seem to be non-stock everywhere we have looked. I do appreciate the input. –  Brandon Bailey Nov 14 '12 at 21:01
@Brandon: Ususally you do the lifetime buy directly from the company that is discontinuing the product. They typically give you 6 months or more notice to place your last order. Their final production run is then sized to meet all the orders they have received. This is to their advantage too. Talk to the manufacturer. They may be more accomodating then you think. They will most likely have heard this from other customers and will have a system in place for lifetime buys. Just don't wait until they have already committed the last production run. –  Olin Lathrop Nov 14 '12 at 21:07

1K MOQ 10mm thumbwheel pot possible replacement (for now)

Specs

-
That does look like it would work. Do you know where that can be purchased? In the US preferably, the link is to a Chinese site. –  Brandon Bailey Nov 14 '12 at 21:03
US? not a chance –  Tony Stewart Nov 15 '12 at 0:05