How should I fit this on

[tehfunk]

So, I am coming close to building the WH10 WAH WAH, so the potentiometer finally came, here is a picture, it is a Bourns 91 series.



not my photo, but you get the idea, the main point is it has a round shaft and because I am building a wah I need to get a gear on there. Most of the pinion gears I see are made for d shafts so they just lock into place, so for d shaft pinion gears can I get some advice on what to do to get the gear on to this round shaft pot.

But, then I see things like this:



It's a round shaft pinion gear, so in terms of this picture, does anyone know where I could get a round shaft pinion gear like this, and secondly, how do they keep it on there?

Help is much appreciated!

[MarcoMike]

I thought the plastic shaft was going to be filed to D shape to fit a normal gear....

[tehfunk]

Yeah, that's what I originally said I was going to do (and might still end up doing). But, before doing anything, I realized that it would be best to ask around to see if anyone knew of a way to put the gear on that requires less work, and doesn't risk screwing up the shaft. On top of that, those pictures of wah pots with round shafts and gears are very motivating, and I don't want to ignore any good opportunities, if you know what I mean.

So any suggestions?

[ayayay!]

Hmm, so you're saying all the pinions are D-shaped in the core, right?  I don't know man.  I'm sure if you rigged up a SOLID jig for it that completely surrounds the pinion, you could easily bore out the center for a full diameter shaft.  BUT, you must use a rock solid jig and drill press. 

Have you checked the local hardware stores?  And I don't mean Lowes & Home Depot.  A lot of the smaller shops have these pull-out trays of all kinds of knobs and hardware.  Y'know, like replacement stuff you'd find in older homes.  They might have those pinions. 

I would think to keep the shaft on it's just a matter of plain old super glue. 

[tehfunk]

okay, that sounds pretty difficult, maybe i'll just file down the shaft as I was originally going to do, probably make some marking with a scratch awl and then file away. Anyway, the pot that i showed the picture of is actually just the bourns life pot from wah-wah.co.uk, and other sites, and it is the same model as the one I bought, but I got it in the 50k variety, so I was wondering how do the people who sell them, "especially for colorsound wahs" expect people to use them if they have round shafts?? Maybe they know?

[tehfunk]

WELL, I did it!
Here are some pics:









I just used one of those flat files by eurotool (from smallbear), at first I tried doing it evenly all together but then decided to get the top to fit then even it out and it worked out great and even has a tight fit. When I eventually    get time for my wh10 i will post a build report.

[Mick Bailey]

My JEN crybaby uses a circular-shafted pot and is cross-drilled through the gear and shaft to take a small 1/16" roll pin. It was like this from new. The pin inserts out of the way of the rack, on the body-side of the pot. I've used the pedal for decades and it's always been fine.