Wah pinion for solid shaft pot

[Govmnt_Lacky]

Does anyone know where I can find a pinion for a SOLID shaft pot?

I can only seem to find flatted and knurled 

[Plexi]

Can be more specific?

[italianguy63]

File a flat on it...

[Govmnt_Lacky]

Can be more specific?

Sure! I need one of these:



But I need it to go onto a solid shaft pot (not a knurled or flatted shaft)

[Govmnt_Lacky]

File a flat on it...

I was thinking about that as an option for a last resort scenario. The other being that I order a knurled and flatted version and use an exacto to "shape" it for a solid shaft pot.

[Fender3D]

If you get the knurled, you can drill it with a proper bit

[davent]

If you get the knurled, you can drill it with a proper bit

Then you have to tackle how to solidly affix it to the shaft, can't have any play between the shaft and pinion.

I'm with Mark, adapt the shaft to a 'D' pinion. Can slowly creep on a perfect fit.

dave

[Fender3D]

Then you have to tackle how to solidly affix it to the shaft, can't have any play between the shaft and pinion...

One good old screw, as in good old whas...

[thermionix]

Usually see a roll pin (split tension pin actually) on the round shaft wah pots.  Drilling that hole through the shaft would be a bear with a hand drill.  Epoxy might hold well enough though, thoroughly degrease everything before gluing, but don't let any (precious) fluids flow down the bushing into the pot.

[digi2t]

File a flat on it...

I agree. That's always been my MO. "D" shaft pinion with circlip.

[pinkjimiphoton]

greg,
talk to joe gagan, he has some that should work.
i use duco cement when i need to do this.. ya can disolve it with acetone if you need to, and it dries into an almost celluloid. works really good for this purpose.

i've tried filing a round shaft to a d and hated it. lotta work.

definitely get a hold of joe. i used stuff i got from him in my askiewnivibe project, and he's a wicked nice guy.

[Govmnt_Lacky]

greg,
talk to joe gagan, he has some that should work.
i use duco cement when i need to do this.. ya can disolve it with acetone if you need to, and it dries into an almost celluloid. works really good for this purpose.

i've tried filing a round shaft to a d and hated it. lotta work.

definitely get a hold of joe. i used stuff i got from him in my askiewnivibe project, and he's a wicked nice guy.

Hey Jimi! Hope all is well....

I tried to email Joe but have not heard back. I did find some old... OLD info from him that he sent me years ago on how to adapt flatted or knurled pinions for solid shaft pots.

I initially tried long ago to file a solid shaft for a flatted pinion and ended up destroying the pots due to vibration. I found its better to modify the pinion and just use a 2-part cement or Gorilla glue.

[digi2t]

greg,
talk to joe gagan, he has some that should work.
i use duco cement when i need to do this.. ya can disolve it with acetone if you need to, and it dries into an almost celluloid. works really good for this purpose.

i've tried filing a round shaft to a d and hated it. lotta work.

definitely get a hold of joe. i used stuff i got from him in my askiewnivibe project, and he's a wicked nice guy.

Hey Jimi! Hope all is well....

I tried to email Joe but have not heard back. I did find some old... OLD info from him that he sent me years ago on how to adapt flatted or knurled pinions for solid shaft pots.

I initially tried long ago to file a solid shaft for a flatted pinion and ended up destroying the pots due to vibration. I found its better to modify the pinion and just use a 2-part cement or Gorilla glue.

OK... pot shaft flattening 101...

First, need a good vice. Something with good square jaws that will hold the shaft without marring it.



Set the shaft low in the jaws. Leave it just high enough that you'll take off some material, but the vice jaws will act as a stopper at a certain point. This also lends the jaws to act as a guide. The straighter you set the pot in the vice, the more even your result will be.



As for the file, don't use a bastard cut, or even a second cut. Use only a double cut smooth. Yes, it might load up on softer material, but you can clean it with a file brush every so often. It will provide a smooth finish, with no risk of chattering. Besides, the way I shown to jig it up in the vise, the vise will absorb any chatter you can dish up. The pot won't feel a thing.

Also, file a little at a time, and check it against your pinion gear for fit. You don't want to go too far and end up with a sloppy fit. It should slide on, but still be fairly tight. If you feel that you're REALLY close (i.e. gear will go one, but it's REALLY tight), then wrap a piece of 320 grit sandpaper onto your file, and finish up with that. Also, DON'T file your flat right up against the pot's bushing either, leave a 1/32" space. You don't want the gear rubbing on the bushing when it turns.

As for the circlip, cut the shaft about 3/16" longer, and use a thin Dremel cutting disk to score the shaft right up tight to the gear. Only a light score is necessary, enough to give the circlip a place to sit. Scoring too deeply will leave it rattling around on the shaft. Besides, the better your filing job is, the less the circlip has to do.

If a Dremel is not available, then... the "Shawshank Method".
A hacksaw blade can do in a pinch. You will have to modify the blade though so as it doesn't chew up your pinion gear. The trick is to lightly grind a 4" section of the blade to get rid of the offsetting teeth or undulation. The offset or undulation is there as a chip clearing mechanism, but in this case, you don't want/need that. You only need to grind one side of the blade, the side that will run up against the gear. Once your blade is prepped, put your gear on the shaft, and using the ground side of the hacksaw blade against it, slow and lightly saw a light groove, working your way evenly around the shaft. This method is a monk's work, but beggar's can't be choosers. Make it your excuse to hit up your significant other for a Dremel. Christmas is always around the corner.

I know that some gears use a spring pin to lock the gear to the shaft, but I'm a bit wary of using this locking method. First, you need a really good drill press, really good bits, a drill press vise, and a Vee block (or a fooking good eye). Or else, you'll just end up with either a hole that's offset from center, or a hole that the pin will fall through. Also, I tend to use the PEC pots for my projects, which have stainless steel shafts. Working with stainless, on a good day, is a beyotch, so it isn't going to cut me any slack when I come at it with a #56 drill bit. Plastic shafts present the opposite problem; get too hamfisted, and you'll oversize the hole in a heartbeat. Also, plastic doesn't fare well with split pins. The pins are hardened spring steel, and will expand the plastic, often breaking the shaft at the hole. Besides, with all the back and forthing that little gear is going to put up with, the hole will mechanically elongate over time anyway. For these reasons, I stay away from the spring pin option altogether.

I've used this procedure on a half dozen or so pots to date, steel and plastic shafts. Never had to glue one. Never had a problem. Glue, to me, is the absolute last resort, or for a temporary repair.

[davent]

The key as i see it... the shaft has to be supported, held in a vice, the body unsupported, otherwise doomed to failure.

dave

[anotherjim]

Excellent description from Dino.

Might I add some 1/4" ID washers over the shaft to protect the bushing. Thickness of washer to give your fitting clearance. If file has a smooth "safe edge", keep that side towards the bush.

I wouldn't use glue or cross pinning, though a pin seems ideal at first thought. It's tricky to make and either unreliable or too difficult to remove in the future.

[digi2t]

Excellent description from Dino.

Might I add some 1/4" ID washers over the shaft to protect the bushing. Thickness of washer to give your fitting clearance. If file has a smooth "safe edge", keep that side towards the bush.

I wouldn't use glue or cross pinning, though a pin seems ideal at first thought. It's tricky to make and either unreliable or too difficult to remove in the future.

Super idea!! Use a washer as a filing guide and bushing protector. Gonna put that one on the metal hard drive.

Thanks!! 

[stallik]

When doing any filing work on a pot, I'd recommend using the toy case out of a kinder egg. Drill a hole in one end, pop the pot inside and close the case. Saves the swarf  getting into the pot

[thermionix]

kinder egg

Banned in the USA.  AFAIK.  Choking hazard I think.

[davent]

I thought they were allowed now that they've totally ruined them and instead of having these incredibly cool, ingenious little models you had to put together, they have a completed crappy toy.
dave

[digi2t]

kinder egg

Banned in the USA.  AFAIK.  Choking hazard I think.

True dat.

http://www.cbc.ca/news/canada/montreal/kinder-surprise-egg-removed-from-easter-townships-man-1.3514283