Pot's, to slide or rotate, that;s the question...

[Tom_G_2010]

I'm getting ready to order the potentiometers for my yoke and rudder pedals. I'm fitting them up to the original Cessna y bar yoke and to Cessna rudder pedals. For each axis I can very easily pick up its full range of motion using a slide pot with very little effort. Or, I could fabricate some type of cam arm linkages to convert the linear motion into rotation,.

Depending on where in the linkage I install them I can use either slide pots or rotating pots.

For aileron movement I can pick up either 90mm of linear movement off one of the cables with a slide pot or 180 degrees or rotation of the shaft, more if I gear it.
For the elevators I can pick up 75mm of linier movement off the belcrank arm.
For the rudder pedals I can very easily pick up 25 to 30 mm or linear motion off one of the cables.


So my question is: Is there any reason to favor one over the other?

Thanks!!!
Tom G.

[Mike.Powell]

Lifetime is an important difference between rotary and slide pots. Rotary pots usually last longer because they tend to be sealed while slide pots are not, and because slide pots (with the exception of linear, resistive position sensors) are not designed for continual motion. If you mount a high quality slide pot so the tab points down, you'll extend its operational life, but if you want to assure a long operational lifetime choose a rotary pot with a 1,000,000 rotation lifetime rating like a Bourns 6639S series unit.

[Tom_G_2010]

Lifetime is an important difference between rotary and slide pots. Rotary pots usually last longer because they tend to be sealed while slide pots are not, and because slide pots (with the exception of linear, resistive position sensors) are not designed for continual motion. If you mount a high quality slide pot so the tab points down, you'll extend its operational life, but if you want to assure a long operational lifetime choose a rotary pot with a 1,000,000 rotation lifetime rating like a Bourns 6639S series unit.

Good Point! Looking at my audio mixer it uses fairly high end 100mm slide pots with a split seal but even that allows some dust in. The aileron is easy to pick up with a rotary pot, the elevator and rudder a bit more tricky.

You mentioned linear resistive position sensors and until just now the ones I've looked were way over the top on price. However a little more digging and I've found some in a more reasonable price range so I'll be looking into their specs to include serviceable life.

I happen to have some high end film and wire wound rotary pots in my parts collection so I can take advantage of those as well, but the linkage has to be figured out.,,