Flush Pedal Knobs

[chromesphere]

Hello fellow forumites!

A friend of mine brought around some of his commercial pedals on the weekend.  One thing i noticed immediately was how ALL of the knobs on them were flush with the enclosure.  I always end up with a gap of 3+ mm between the base of the knob and the top of the enclosure.  The commercial pedal knobs had very little gap, and it just occured to me how much better it looked.

So the question is, how can you remove a small amount from the top of the potentiometer?  I'd have to experiment, but i reckon 3-4mm.  Or should i just take off more, say, half a centermeter or even more, and just make sure theres enough for the grub screw to hit?

Do any of you guys do this extra step?

Cheers,
Paul

[digi2t]

I do. I like them flush, so I trim the tops of the shafts with a Dremel, when required.

[deadastronaut]

hi paul, i always cut my shafts (solid) to fit my knobs onto..i'm not a fan of split shafts. (though i picked up a good tip for those, use the snapped off lug and put it in the split, voila' no squeeze) ...anyway...

you could always add another nut/s to the pot underneath too...just to test.

[R.G.]

Look up "jeweler's saw" or "Zona saw".

[R O Tiree]

You can just file it down for up to 1mm or so, or use a fine-toothed junior hacksaw to take more off. Whatever you do make absolutely sure that no little shards of metal get inside the pot body - they get stuck in the grease inside and then wear the track out in a heartbeat.

If the knob is deep enough, you can use a 6.35mm drill (1/4") to make the recess deeper...

Or buy taller knobs - that's what I ended up doing. Saves a lot of hassle.

[davent]

Drives me crazy when i see floating knobs. Small Bear pots have shafts length appropriately so it's unnecessary to take the extra step. When it is necessary, because i've sourced the pots elsewhere i use a hacksaw or Dremel with a cutoff wheel. Best to grip the excess bit in the vise to do the surgery. Wrap some tape around the lower part of the shaft and the pot body to prevent stray bits going where they shouldn't be.

Sometimes only takes i bit of filing to get where i need or it could be a long bushing requiring a lower mounting of the pot.

dave

[joegagan]

why get all fancy with saws and stuff when a good blow with a hand sledge ( no larger than 4 lb tho) will do the trick.

[John Lyons]

Use a lock washer between the pot and enclosure (inside).
Depending on the knobs you can also drill them out to
take up some space.
I drill out knobs all the time to get the
them closer to flush. A pain but I cant stand it otherwise.

Set the drill stop on your drill press once you get the depth set. 

[chromesphere]

Lock washers, dremels, all good ideas thanks!  I usually use a hacksaw, but the small amount to trim might make it a pita.  I'll mess around with it this afternoon.  Its funny, i've built 100+ pedals, and its ALWAYS bothered me.  Then i noticed the commercial pedals and thought, "thats it! I've had enough!" lol
Paul

[samhay]

I used to use a hacksaw. Once I got a Dremel, I was suddenly a lot more compelled to trim my pot shafts.

[Jdansti]

Another way to take a little off the end of the shaft if you don't have a Dremel is to turn the pot upside down, hold or support the shaft with some pliers (or your fingers if you can), and rub the flat end across a flat file or some 60-80 grit sandpaper. I often do this anyway after cutting the end with a Dremel.

Using washers as spacers on the inside as John L. mentioned is the quickest and easiest way.

Speaking of stick-ups, I also hate to see a bunch of threads on a switch or jack hanging out of the box. Sometimes it's unavoidable due to space constraints on the inside of the enclosure. I usually use an extra nut on the inside to adjust adjust them.

[deadastronaut]

with these, you have no choice but to put it in a vise and saw...then file...a bit pricey too , but i do prefer the feel of these,than most others ive tried,  more 'resistance' (ok bad pun) when turning.
http://www.maplin.co.uk/miniature-potentiometers-2203

[Kesh]

Has anyone tried recessing the knob? My plan is to drill holes the size of the knobs then attach a plate of aluminium behind, drilling your normal pot holes in that.

[deadastronaut]

^ probably not due to space for the pcb, ...but i get the idea, like a ross distortion flushness etc...

[Perrow]

When I saw the thread title I got an image of a knob that had it's top flush with the enclosure. That would require some texture on the top of the knob and a pot that's not too hard to turn, but you'd never destroy that pot with careless stomping

[greaser_au]

When *I* saw the title, I thought Paul was advocating universal disposal of all knobs via the sanitary facilities....  

I'm a big fan of jigs and templates generally, so I'd suggest once you know how long the shaft needs to be to suit the enclosures and knobs in use, that you drill a suitable close-fitting hole (maybe even a stepped hole such the bush of the pot  also enters,  (and a small hole for the lug) so that the body sits flat) in a piece of some material (say hardwood) and thickness the material so that a) it is easy to gauge the amount to be removed, and b) keep the swarf/filings away from the body of the pot while you cut/file/sand/grind/machine the top of the shaft. Also... ink/paint the face of the jig so that you know when it's worn out from contact with the cutter.

david

[davent]

Has anyone tried recessing the knob? My plan is to drill holes the size of the knobs then attach a plate of aluminium behind, drilling your normal pot holes in that.

Not a pedal but the same idea.

[deadastronaut]

^ very sweet.. 

[Mark Hammer]

Use a lock washer between the pot and enclosure (inside).

Bingo.
Pots NEVER come with lock washers.  They DO come with those little tabs to fit in a chassis hole and keep the pot steady, but not the locking washer.  Precious few of us use that tab as intended, since it involves more work and more precise machining.  The locking washer has no such limitations, and provides a very convenient way of not only keeping the pot steady so that it doesn't rotate inside as you tighten the nut outside, but also serves to "lower" the portion of the pot stickig out above the surface of the chassis.

Buy thineself a bag of locking washers.

[davent]

On some pots (or with thick walled enclosures) the bushing isn't long enough to allow for the lockwasher and still have a enough thread exposed topside to engage the nut so  before you snap off the anti-rotation tab check that there's enough threaded bushing.
dave