Controlling 2 pots w/one shaft?

I have two pots I would like to control with a single shaft. The pots are adjusted with a Phillips screwdriver, and the + shaped slot slot goes completely through the center of each pot, so I am thinking a + shaped shaft linking the two would do the job. What would such a shaft be called? And how could I put a knob on it? Anyone have any ideas?

Much thanks for any help...

Dave

Reply to
Dave
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shaft

Why not just purchase a dual pot? They're pretty cheap. See, for example, the bottom of:

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Reply to
Greg Neill

Well, I am working with some specialized pots for a specific appliction, and the thing is that I need to use the pots I have because nobody makes a dual pot like what I need. So, I am looking for a + shaped shaft to link these two, so I can turn them in tandem. I have already fabricated something as a temporary fix, but I need something more permanent. Thus, the questions.

Again, I am all ears.

Thanks,

Dave

Reply to
Dave

Have done something similar in the past, where the need was for four pots activated from a common spindle. You can easily link two dual-gang pots via a sliver of metal from the back of the first to a slot cut into the shaft of the second. Mechanically link the two units together by stiff wire soldered onto the pot bodies - they'll readily take solder. As Greg points out, dual gang pots are available, but only in limited (usually matched) values, and if you wanted to marry, say, a 470 ohm lin with a

2.2K log, you'd have to do a bit of deconstruction. The linking piece of metal doesn't have to be + shaped though. A simple flat sliver, securely glued between the two pots will do the job.

Cheers, Pete.

Reply to
Pete Wilcox

Yes, what you desscribe is basically what I have done to this point. Soldered the pot bodies together, and used a couple of metal shims to link the pot shafts. Am just wanting something a lot more permanent than those two metal shims. But what you want and what you get...

Thanks for the replies.

Dave

Reply to
Dave

--snip--

Dave,

I assume you're talking about the small PC-board-mounted type of pot.

If you need a piece of X-shaped "rod", you might check your local hobby store for plastic or brass extrusions. Or, if you have some sheet metal lying around (old Coke can?) cut two identical rectangles, each of which will fit between the pots, and then cut matching slits in each so they slide together to form an X-shaped shaft, e.g. two of these (best viewed with a fixed-width font):

+----------------------------------------+ | | | | | | | +--------------------+ | | | +--------------------+ | | | | | | +----------------------------------------+

Okay, that's a bit exaggerated, but you get the idea.

How to turn them? Well, there's always the old fishing-line-or-dial- cors-and-pulleys-attached-to-a-knob trick, popular years back when radios were tuned by physically rotating a capacitor or moving cores in and out of inductors.

Hope this helps...

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Reply to
Frnak McKenney

Used a 10/32 2" panhead sheetmetal screw (which the malleable plastic pot spindles accepted nicely) to link the pots. Put about 5/8" of the screw on the knob-side, and it fits nicely into a knob I have fitted for a 1/8" shaft. Was originally concerned about making sure both pots were set alike (zeroed out completly, at the same time) and installing this screw accomplishes this automatically. Used a dab of E-6000 to glue the front pot to the inside of my chassis, with the screw centered in the mounting hole. Propped it up to dry, and left it alone for a while. Done.

Just a note for anyoen trying to do something similar in the future. Started to use a drywall screw, but it didn't fit the knob as well.

Reply to
Dave

Hey there dave, im not a huge electronics buff, but look into something called a "dual ganged pot"..basically one pot with two shafts...im not sure if they can have different resistances per pot...but hit up mouser for one. good luck!

Morgan

Reply to
morganpartee

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