Broken Shaft Question ;)

[Ginsly]

Not a pedal, but not much bigger...

I have a crappy Fender Frontman 15r that I wound up with, and the Treble pot shaft is mostly broken off. I'm going to get a close-enough witch hat knob from AES, but the knurled, plastic shaft is just a stump. Insert joke here.

I had put a bit of stiff tubing into a chicken head knob and shoved that onto the stump, but now that I'll be getting a better knob I'd like to figure something else out. I'd replace the pot, but don't know the value of the Treble control. Finding an original seems tough, outside of spending 60 bucks for another 15r! The pots look like kinda like this, although I haven't opened it up to see the base yet:

I could possibly drill a tiny hole in the stump and glue a brace in there, but I'm not sure what I'd use to "create" the missing shaft piece before gluing it on. Don't have access to 3D printing. This all seems like a HUGE waste of time, but for reasons unknown I want to finally "fix" some of my old, junky amps.

 

[Brett]

I'd replace the pot, but don't know the value of the Treble control

Here, I googled it for you.

 

[Ginsly]

Here, I googled it for you.

I was wondering more if anyone has actually “fixed” a pot shaft in this situation.

 

[Brett]

I'm sure they have... by replacing the broken part. Drilling into a plastic shaft potentiometer and jerry rigging something and hoping for the best isn't what I'd consider "fixed".

 

[Brett]

Also you said this:

I'd replace the pot, but don't know the value of the Treble control

Now you know the value of the pot...

 

[Ginsly]

Classic Brett-sponse!

No BS!

To the point!

Mildly aggravated!

Just joshin ya bud! I of course did Google it but was still having trouble locating the specific Treble value. Sometimes people around have smart ways of fixing things, thought I’d also ask about that. But I hear ya- this is probably not one of those times. I do appreciate you chiming in. I can handle the tough love.

 

[Brett]

Mildly aggravated!

Not aggravated, just confused why you'd want to try to jerry-rig something that you'll almost certainly end up having to fix again.

Use a comparable or equivalent part and fix it right the first time.

 

[Ginsly]

Here, I googled it for you.

I mean… a bit passive aggressive to add that to the link, but I get it, man!

More importantly I appreciate the assist. Google comes up with different stuff for different people sometimes.

 

[Nic]

100K 30C is what it looks like to be from the schematic.

 

[RetiredUnit1]

You can always just disconnect the wires and measure the resistance. As you sweep the knob see if the resistance is linear or not. But schematics are much better, lol.

 

[Chuck D. Bones]

30C (30% log taper) might be hard to find. Most audio-taper pots I see for sale are 15%, which will work just fine. For that matter, a linear pot will work there too.

 

[RetiredUnit1]

30C (30% log taper) might be hard to find. Most audio-taper pots I see for sale are 15%, which will work just fine. For that matter, a linear pot will work there too.

Definitely. The Fender Tweed Deluxe, 5E3, specifies linear pots for the volume, they work MUCH better with audio taper.

 

[RetiredUnit1]

Here is an option you can try, Grab a Alpha 16 mm long splined pot & pull the Tin cap of the back and file the cente shaft til it seperates the plastic wiper & little black washer & the shaft will slide out.
Put a piece of plastic cable tie in the spline groove to stop it from squashing as it will go into the chuck of your drill.
Just tighten it enough so it wont fall out.
Get a course file as aluminium will block anything fine & make sure it has a smooth edge on one side so it wont dig into the Shaft.
Start up the drill & file the inner shaft down to a diameter of aprox 4mm or a bit less.
Drill a Hole into the centre of the shaft stump on your pot to the same size as the aluminium inner shaft.
Test to see if it will slide in firmly & if possible , file the stump so it is square on the front so the Aluminium shaft can butt up square.
Use good Supa glue & you should be good!
This is what I did to a Pot to demonstrate what it will look like:

View attachment 73137

So, would modifying pots be called Pottery?

 

[music6000]

Not a pedal, but not much bigger...

I have a crappy Fender Frontman 15r that I wound up with, and the Treble pot shaft is mostly broken off. I'm going to get a close-enough witch hat knob from AES, but the knurled, plastic shaft is just a stump. Insert joke here.

I had put a bit of stiff tubing into a chicken head knob and shoved that onto the stump, but now that I'll be getting a better knob I'd like to figure something else out. I'd replace the pot, but don't know the value of the Treble control. Finding an original seems tough, outside of spending 60 bucks for another 15r! The pots look like kinda like this, although I haven't opened it up to see the base yet:
View attachment 72787
I could possibly drill a tiny hole in the stump and glue a brace in there, but I'm not sure what I'd use to "create" the missing shaft piece before gluing it on. Don't have access to 3D printing. This all seems like a HUGE waste of time, but for reasons unknown I want to finally "fix" some of my old, junky amps.

Here is an option you can try, Grab a Alpha 16 mm long splined pot & pull the Tin cap of the back and file the cente shaft til it seperates the plastic wiper & little black washer & the shaft will slide out.
Put a piece of plastic cable tie in the spline groove to stop it from squashing as it will go into the chuck of your drill.
Just tighten it enough so it wont fall out.
Get a course file as aluminium will block anything fine & make sure it has a smooth edge on one side so it wont dig into the Shaft.
Start up the drill & file the inner shaft down to a diameter of aprox 4mm or a bit less.
Drill a Hole into the centre of the shaft stump on your pot to the same size as the aluminium inner shaft.
Test to see if it will slide in firmly & if possible , file the stump so it is square on the front so the Aluminium shaft can butt up square.
Use good Supa glue & you should be good!
This is what I did to a Pot to demonstrate what it will look like:

 

[Ginsly]

@Chuck D. Bones yep that 30c was the part that really confused me. I found this and figure it’s pretty close, though it doesn’t specify 30c: https://www.tubesandmore.com/products/potentiometer-fender-100k-reverse-audio-d-shaft-snap

@music6000 holy cow! Thanks for the walk-through- if the pot in the link above isn’t right, this is likely what I’ll do.

 

[Brett]

Have you tried calling FMIC to see if you might be able to order the replacement part? I've dealt with them directly in the past.

To save you a couple minutes, the part number you're looking for is 037324 and the phone number for FMIC customer service is 1-844-202-0924.

 

[Ginsly]

Have you tried calling FMIC to see if you might be able to order the replacement part? I've dealt with them directly in the past.

To save you a couple minutes, the part number you're looking for is 037324 and the phone number for FMIC customer service is 1-844-202-0924.

Thanks Brett! Not a bad idea.

I actually found that potentiometer link for AES by looking up “Fender 037324”- first result! Might not be a 30c, but it’s likely close enough.

I’ve emailed with Fender consumer relations in the past, they were decent- no Dunlop/MXR, though! They’re excellent with this kinda thing.

Much appreciated man!