How to prevent unwanted volume adjustments on volume knob of a portable amp

[thelegendaryblah]

hello everyone
i am quite a newb on diyaudio but have quite a good background in electronics

i made a few cmoys just for practice and after using them for a while, i realised there is quite a huge problem i am having with the volume adjustment pot

basically, i use a sansa clip connected to my cmoy when i go out and i have both of them in my jacket pocket, i noticed that the volume gets adjusted quite a lot due to friction from my jacket. the inside of the jacket would rub against the knob and cause it to turn and adjust the volume, is there some kind of device for "locking" the pot to prevent it from turning?

sidenote: i have a fiio e11 as well and there is a frame around the pot to prevent it from spinning, will it be possible to do something similar to that with a diy case/chassis?

 

[Fredfred2004]

Quick and cheap solution, push the knob on firmly and slightly bend out the lid of the tin so they rub and it will stop the turning

cheers
FRED

 

[sofaspud]

Do you have a photo? Maybe the easiest fix is to just remove the knob from the pot shaft. Not the prettiest solution, but it's hidden in your pocket anyway.
Or, a felt or rubber washer under the knob to increase the torque required.

 

[vixr]

Fred beat me to it...

 

[thelegendaryblah]

thanks for all the replies guys (didnt imagine the man that is fred himself would reply to my thread)

unfortunately i am not using an altoids tin as i am using a serpac h65 from tangent's recommended parts list, unscrewing the knob from the pot shaft is surely going to work but i will really prefer not to.

a rubber washer seems like a nice idea, where could i get one of those? (or should i find a super tight rubber bands?)

here's a pic if it helps

thanks

 

[sofaspud]

Does your workshop look anything like mine?
First thing I would try is a round piece cut from an old bicycle inner tube.
Maybe a razor slice from a rubber equipment foot, or the hardware store likely has something in stock in the plumbing or fastener department.

 

[thelegendaryblah]

i think i have some stick on rubber pads sitting around here somewhere, will try using them and see whether they work or not

PS: sorry to disappoint, but i don't have readily available access to any workshops/labs (because i am a college student studying abroad working towards a EECS degree )

 

[Fredfred2004]

Just use a rubber band, lengthways over the amp and the knob

cheers
FRED

 

[KatieandDad]

Cut the shaft off the pot and cut a slot in the end so you need a screwdriver to adjust it.

 

[thelegendaryblah]

using a rubber band (i used one that is about 5mm thick) lengthways over the amp actually works really well, thanks everyone

 

[vixr]

I have some round felt pads that are used on the bottm of stuff to keep it from scratching a table top...one side is just soft felt and one side is sticky. I got a sheet of them from home depot, that includes various sizes and they had a few colors too. Maybe you could find a suitable size, punch a hole in it and place it between the knob and the front panel with the pot shaft sticking thru the hole in the center of the pad. When you re-install the knob just push down enough to get it firmly against the felt... This would offer enough resistance to keep the pot from turning freely, and would be somewhat adjustable.