Stupid but valid question about knobs and pickup covers

[PoPo75]

I'm building a spare parts guitar. Most of the stuff I had laying around but I didn't have knobs and I decided to put pickup covers on the humbuckers. So off to ebay I went. I ordered a 2 pack of Pro Line brand chrome pick up covers and a set of speed knobs. Everything total cost less than $20. I'm going cheap on purpose. Anyway, the pickup covers didn't fit ANYTHING. I tried dimarzio F spaced and non-F spaced, Epiphone pickups, Gibson pickups and even a Washburn pickup I had laying around. What's the deal? It said they should fit 51mm and 52mm pickups. Are there other measurements? The cover slid over the pickup fine but the holes didn't line up with the pole pieces.

Now for the knobs. I'm using Gibson pots. The knobs would not fit the shaft of the pot even if I crimped it down a little bit.. I actually broke one of the split shafts trying to get it to fit. I know there is a difference between import and American made parts but do I really have to spend $20 on Gibson brand knobs? Or can I get the cheaper ones in different sizes?

In all of my years of playing and modding guitars,, changing pickups and knobs, etc, I have never encountered this problem.

[Chuck H]

I've dealt with the pole spacing thing before but only with plastic strat covers and they were only a tad off. I just had to oval the two outermost holes on either side an almost unnoticeable amount. Should be a real problem with chrome covers though. Maybe they just spaced them in between?!? Buyer beware with non OEM parts and aftermarket trim for sure. The knob problem doesn't surprise me at all. Speed knobs usually have narrow bores IME. I've drilled them out a couple of times to make them work. And I too broke a fin off a split shaft once tying to cram a speed knob onto it. That's how I figured it out. The good news is that you'll only do it once

[Steve A.]

There are two basic versions of spline shaft pots, US and imported. If the knobs are too small, you can ream them out a little bit as Chuck H. suggested. If the knobs are too big you can spread out the split shaft... very carefully. Here are the details from StewMac:
* CTS pots (USA) use a fine-knurled (24-spline) knob
* Alpha pots (imported) a coarse-knurled (18-spline) knob

As for pickup covers that is a whole other matter. I think that they were all the same until someone came out with the F-spaced bridge pickups and all hell broke out. Gibson now has different spacings for some of their neck and bridge pickups, not to mention the other companies like DiMarzio, etc., along with the OEM's.

I got burned with those ProLine covers, too, but fortunately I bought them at the local GC so there was no problem returning them. So unless the seller guarantees that their cover will fit a specific pickup I would stick with the same mfg and I ended up ordering DiMarzio covers for a pair of DiM pickups I got really cheap on eBay. Or just order them with the covers if they don't that much more.

Actually it is time for those open top humbucker covers to return. I picked up some in the 80's and they protect the windings but still allow the top to "breathe". Here is one listing at eBay if you don't mind waiting for a slow boat from China. (I just ordered 6 of them so I will have them around when I need them.)

http://www.ebay.com/itm/Chrome-plate...s/311276424711

Steve Ahola

P.S. You might check with Google for covers for the specific pickups you have. And measure the spacing of the pole pieces. BTW I ran into a problem with the metal P90 covers on an Epiphone Casino about 20 years ago- I got a pair of Gibson P90s but the holes in the covers didn't line up so I reamed them out which looks kinda funky.

[Chuck H]

I might not get THAT one unless I were willing to do a little added work myself.

[eschertron]

I might not get THAT one unless I were willing to do a little added work myself.

Whaddya mean? When I do re-work it always turns out looking like that!

[Steve A.]

I might not get THAT one unless I were willing to do a little added work myself.

Yikes! I hope that is just a prototype. It is easy enough to grind it smooth with a Dremel tool but that would make it easier to rust...

Steve A.

[PoPo75]

Thanks for your thoughts guys