Anyone got ideas about how to get knob off effect pedal?

[9 volts]

Hey there I need to get into a pedal, the screw that holds the knob onto the pot has rusted,

i've tried a little  spray (wd40) with no luck. Anyway idea's to get it off without damaging knob? Thanks

[MikeH]

Get a reverse-drill bit (drills turning counter-clockwise) and drill it out.  Either you'll drill all the way through the screw and just have to fish out the pieces or the bit will break it free and turn it out.  Just make sure you dont use one that's too big or you'll ruin the threads on the knob!

[birt]

easier but a it can be a bit messy... coca cola.
ut the pedal upside down on some kind of support so the knob is just deep enough in some coca cola (or pepsi if you want :p) to soak that screw. leave it for a couple of minutes and try again.

[andrewb]

be careful if you try to drill it out....
i recently wrecked a pot on an ibanez pedal....
not the end of the world... but hard to find replacements....

my advice would be to try and put a grove in the screw with a small engraver bit...
then try your best to get it out with a screw driver....

[deaconque]

you could also drop some CLR into the screw hole for a couple minutes, so it can eat some of the rust away, then try the screwdriver again.

[9 volts]

Thanks all, got a few ideas to try here.....never heard of a reverse drill bit from what i just read you run the drill in reverse also, yes?

[hday]

A reverse drill bit is used for drilling out screws. A normal bit drills clockwise, the same direction that the screw turns. A reverse bit turns counterclockwise and has a bit more grip to it, so when it drills a hole, it's also trying to turn the stuck screw out. I've used this before on other screws and they're tough to use. I'd try everything else before trying to drill it out. Did you try giving it a lot of torque? Find a screwdriver that fits the groove well and push in while turning hard. A screw that small can't rust too tight, but I may be wrong having never seen it.

[Paul Perry (Frostwave)]

is the problem a stuck grub screw, or is the knob somehow stuck to the shaft?

If it is the grub screw, sometimes you can get a damaged screw with a damaged head to turn, by putting some carborundum grit (mixed with oil) on the screwdriver tip.
This increases the friction by about 5 times, so the blade grips better. It is possible to get tiny bottles of this stuff ready mixed.

If you get desperate & try to lever the knob off (never a good idea..) at least lever BOTH SIDES at the same time, evenly. Otherwise it is 100% doomed.

[Drake120]

Well, I think I can ask my question here.

I also want to get knob off from a pedal, but the knob doesn't use screws. I think it's just "pushed" onto a pot, but I can't pull it away (well, I don't want to broke the pot so I'm making it quite gently). What's the way to get the "pushed onto" knob off?

Thanks,
(JD)^S

[birt]

2 tea spoons. use them as levers.

[earthtonesaudio]

Teeth.  Don't tell your dentist though.   

[liddokun]

wrap a t-shirt or towel around the knob so that the tshirt goes underneath the space between the knob and the enclosure. Once you have a secure hold, just pull. I use this to get knobs off guitars.

[deaconque]

wrap a t-shirt or towel around the knob so that the tshirt goes underneath the space between the knob and the enclosure. Once you have a secure hold, just pull. I use this to get knobs off guitars.

+1.  I've used this method many times on guitars with stuck knobs

[R.G.]

Evapo-rust.

No, really. That's a real product that chemically eats rust.

[Paul Perry (Frostwave)]

Amazingly enough, the chemical is said to come from molasses.
http://www.wr6wr.com/newSite/articles/columns/wp0906/wp0906.html

But, using actual molasses is as slow as...  well, molasses.

[any]

Just out of curiosity after reading that article, would it be possible to etch PCB with that molasses solution?
(as it ate the copper off the welding rod.) Just wonder if press'n peel or sharpie would be enough as an etch resist...

[Paul Perry (Frostwave)]

I expect it would be REALLY slow as an etch, weeks at least!

[9 volts]

Great stuff, I think I'll be trying some molasse or  Evapo-Rust on my car as well! (plenty of stops to test). Great thread, I'll keep you posted with my results, thanks again