Stuck volume or tone control shaft ? EASY FIX !

Back in the '20s and '30s radio magazines ran tips from readers. Here's the Forum version; post your ideas and radio fixes here to share with the rest of us. Ads are not permitted.
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oldradioparts
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6740
Jan Thu 01, 1970 12:00 am
Plymouth, MI
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Stuck volume or tone control shaft ? EASY FIX !

Post by oldradioparts »

Stuck shafts on controls are due to the grease in the bushing drying out. To fix this, first get some WD40 or similar stuff all over the shaft where it exits the bushing. Best to have the shaft facing up so the liquid will work down into the bushing.
OK HERE IS THE SECRET.... HEAT THE BUSHING with a chisel tip solder pencil to melt the grease inside ! Once it starts to melt inside, put a knob on it and work the control a LOT ! Add more solvent/lube until it really gets into the bushing.
The chisel tip allows more surface contact to the bushing. Sometimes there is a little "play" in the shaft you can pull it out a little and get more lube into the joint where it exits the bushing.
This works about 95% of the time.
CAUTION ! If it was a volume control (especially ones with power switch) it was probably left in the "off" position so turn clockwise. If its a tone or other control with no power switch, could be it was left in the full CW position so turning it more can break it... so, if stuck control has no power switch, might be best to 'ohm test" the control to see where the wiper is positioned. wiper is the center of the 3 close lugs. If you read zero or low ohms to one of the "outer" lugs, then thats the one the wiper is near and you can then picture which way its safe to turn it.
Last edited by oldradioparts on Oct Sun 02, 2022 6:58 am, edited 3 times in total.
Mark Oppat
Antique Audio
Plymouth, MI
http://www.oldradioparts.net
John Bartley
Moderator
14907
Jan Thu 01, 1970 12:00 am
Monteith, Ontario, Canada

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by John Bartley »

Not really a secret there Mark. We recently had a whole thread on just this issue and how to solve it with heat and lube.

There's also a "pot-lubing" device that I have seen but cannot find today which screws onto the pot mounting bushing and allows you to use grease gun pressure to inject lube between the shaft and bushing.
After spending a life on the couch ... what is there to retire from?
Retired Radio Man
Member
7349
Jun Sat 09, 2007 7:14 am
Melbourne, Florida

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Retired Radio Man »

Thanks for the suggestion Mark.

RRM
ArtFromNY
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1948
Feb Tue 11, 2020 10:43 pm
Mechanicville NY 12118 USA
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Re: Stuck volume or tone control shaft ? EASY FIX !

Post by ArtFromNY »

John Bartley wrote:Not really a secret there Mark. We recently had a whole thread on just this issue and how to solve it with heat and lube.

There's also a "pot-lubing" device that I have seen but cannot find today which screws onto the pot mounting bushing and allows you to use grease gun pressure to inject lube between the shaft and bushing.
A trick I learned from fixing stiff focus rings on 35mm camera lenses is to use isopropyl alcohol dispensed from syringe with a 28 or 30 gauge tip - works a lot faster, at least for me, than WD or PB Blaster.

Art
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Macrohenry
Member
7354
Jan Thu 01, 1970 12:00 am
Austin TX

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Macrohenry »

Thanks. Saved me from having to post to see if it's OK to use heat on a pot.
It's hard to be simultaneously curious and annoyed
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Jon S.
Member
314
Dec Fri 31, 2021 1:40 am
Tehachapi, CA

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Jon S. »

This really works! I had a COMPLETELY FROZEN tone control on a 1942 Firestone "Olympic" S-7398-2. You suggested this heat/WD-40 method, and BINGO - worked like a charm! Thanks for the great tip - And even if there had been a prior thread on this, people need to see (or be reminded) of such great hacks. Keep 'em coming.
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Paul Dietenberger
Member
6492
Jan Thu 01, 1970 12:00 am
Oak Creek, WI USA

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Paul Dietenberger »

Well, I missed the first one and also this one until just now.
dacsman
Member
623
Dec Thu 10, 2015 6:01 pm

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by dacsman »

Heat is your friend for sure whether stuck control or threaded parts. Depending on where the metal part is, how much room is available around it, and if discoloration from heating the metal part would be an issue... I've also used my mini butane torch to provide the heat rather than bring out my soldering iron. Usually use Sili-Kroil in place of the WD40, alcohol, or others mentioned. All will work fine with the addition of heat to get things moving.
DenisN
Member
498
Oct Sun 18, 2015 1:49 am
San Angelo, TX 76904

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by DenisN »

I have jammed the shaft between the legs of my Weller gun tip to get heat. Also works great to solder pin jacks. Denis
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Lou deGonzague
Moderator
10717
Jan Thu 01, 1970 12:00 am
Latham NY 12110

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Lou deGonzague »

As mentioned by John GC sold an adapter that would thread on the VC shaft and allow your cleaner to go past the shaft and into the control. This was very handy for those sealed controls with no opening to inject the cleaner. I made my owm by soldering a nut onto this fitting . I use some Teflon tape to make a good seal and the fill it with my favorite cleaner Jiff Action from GC. I can add some pressure if needed from a syringe.
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FrankB
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2985
Jan Thu 01, 1970 12:00 am
Olympia WA

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by FrankB »

IIRC the injector was called something like 'Inject-a trol".
One of the few tools I never have found.
FrankB
WB7ELC
(Yes, that is actually me in the avatar photo)
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diskcopy
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131
Mar Tue 16, 2021 11:23 pm
Pacific, Missouri
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Re: Stuck volume or tone control shaft ? EASY FIX !

Post by diskcopy »

FrankB wrote:IIRC the injector was called something like 'Inject-a trol".
One of the few tools I never have found.
Are you thinking of the Trolmaster? I have one, but the brass shell is cracked, and the "magic solvent" is long gone, so it's more of a showpiece. I wonder what was in the "magic solvent"... :lol:
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To reach the Truth it is necessary...to put everything in doubt so far as possible
- Descartes
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stevebyan
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May Wed 18, 2011 1:40 am
Littleton, MA
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Re: Stuck volume or tone control shaft ? EASY FIX !

Post by stevebyan »

diskcopy wrote:I wonder what was in the "magic solvent"...
Likely it was carbon tetrachloride.
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Lou deGonzague
Moderator
10717
Jan Thu 01, 1970 12:00 am
Latham NY 12110

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by Lou deGonzague »

You should be able to solder that crack.
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diskcopy
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131
Mar Tue 16, 2021 11:23 pm
Pacific, Missouri
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Re: Stuck volume or tone control shaft ? EASY FIX !

Post by diskcopy »

I thought about soldering the crack, but since this is a unique tool, I'm hesitant about messing with it.
To reach the Truth it is necessary...to put everything in doubt so far as possible
- Descartes
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FrankB
Member
2985
Jan Thu 01, 1970 12:00 am
Olympia WA

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by FrankB »

I think it was Trol- Aid, "Inject-A-Trol" or similar. I'd have to hunt through my service magazines to be sure. Was sold in the 40's-60's IIRC.
Pretty much similar to the injector shown in the pix though.
Great nostalgia item.
FrankB
WB7ELC
(Yes, that is actually me in the avatar photo)
desertbard
Member
701
Oct Thu 09, 2008 2:23 am
El Paso, Texas, USA

Re: Stuck volume or tone control shaft ? EASY FIX !

Post by desertbard »

diskcopy wrote:I thought about soldering the crack, but since this is a unique tool, I'm hesitant about messing with it.
Maybe a machine shop could replicate it for you.
Little old man in the mad scientist's lab at the back of the house.
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