Draw / Cable / String potentiometer

Technical Electrical
#1

We’re looking for a draw / cable / string potentiometer for our hi-lo.

Our biggest reliability issue during our Grand Blanc competition was that the potentiometer would inevitably miss an occational count or skip a tooth when we accelerated the hi-lo up and down at full speed.

I understand a number of teams have found inexpensive string pots that extend up to 50".

Does anyone have a supplier or product line in mind that we could get in a hurry? I dug through digikey, but couldn’t find anything in their labyrinth of sensors.

#2

In Lubbock, 2468 had a clever design that used an Office Depot badge extender, a few 3D printed parts, and a 10 turn potentiometer. You might contact them and see if they could help you out.

#3

Check these out.


We use them for our angles on our shooter mech and they work great. They are rather expensive, but they are worth it.

#4
#5

We used the same for a telescoping arm in 2011. Expensive, but worth it if you don’t have other options. Here’s another manufacturer:
http://www.micro-epsilon.com/displacement-position-sensors/draw-wire-sensor/index.html

#6

Here are a few pics of the device we designed.

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#7

Slightly off topic, sorry could not resist.

You may be from Michigan if you call a lift truck a hi-lo. LOL.

#8

Ditto on these. Used the 50" SP-series in 2011 and this year so far (just ordered a 25" throw one for this year from their Michigan sales rep. I personally think they’re great, and we havent had any problems with them, especially if you buy pre-terminated ones. On the 50, we filtered out a bit of bouncing around in 2011(once you got to the hundredths of a volt). This year, we haven’t found the need to do so.

#9

In the past, we have modified a retractable dog leash to mount pin encoder inside. Dog leash is readily available part, but I am not sure if it has too many turn for your pot. It also clips onto the arm easily.