Omeg pots for mounting PCBs 'trick'

[gez]

If you bend the lugs of Omeg pots down you can use them to mount PCBs.  There’s just enough clearance for most components, though large value electrolytics have to be mounted on their side (or you can use axial).  If there isn't enough room you can always use dual-gang pots for more clearance.



I bought some of these pots years ago and never used them as they’re quite chunky, but this makes them ideal for PCB mounting if your effect only has a couple of knobs as the pins are quite beefy.  They can support a fair bit of weight.



I’ve done a number of boxes like this now and have had no problems.   It does mean a little less space, but those little Bourns pots wouldn’t cut if for just two knobs (and Rapid have stopped selling them).

The Omeg pots have a real pro feel to them, very much like turning the knob on a hi-fi.  They’re enclosed so they shouldn’t get that scratchy with age, plus the tracks are ‘conductive polymer’ which is quieter than carbon.

In the UK Rapid and Maplin sell them.  ESR do the dual-gang type.

[Ansil]

SWEET

[Jason Stout]

Cool! Where can I find them?

[ExpAnonColin]

I've been doing that with the futurlec pots for a while:


You can bend the leads at an angle, although I spose your method allows for more component clearence.  I did one thing on non-pad-per-hole perf witht he pots coming out of the wrong side once.  There are also always those good old mouser pots that come with 90 degree angle leads and are cheap, too, which would allow for a lot of clearance:
http://www.mouser.com/index.cfm?&handler=data.listcategory&D=*31VQ*&terms=31VQ&Ntt=*31VQ*&Dk=1&Ns=MfgrPartNumber%7c%7cSField&N=0&crc=true

-Colin

[Paul Perry (Frostwave)]

The thing to avoid is the possibility of a 'springboard' effect, either have a pot at each end of the pcb or else pack a foam block or something under it to stop it bouncing, if it is a big pcb.

[gez]

The thing to avoid is the possibility of a 'springboard' effect, either have a pot at each end of the pcb or else pack a foam block or something under it to stop it bouncing, if it is a big pcb.

Yeah, I was worried about that too Paul but when the thing is clamped into a box it seems to be rock solid.  My boards aren't that long though.  I would advise making the PCB pads for the pots slightly larger than normal though and also to use a good splodge of solder for firmness.

I only know where to get these pots in the UK Jason:

www.rapidelectronics.co.uk

Omega have a website though (sorry, don't know the address) so you should be able to find a local distributer linked from it.

Mouse, you can use dual-gang Alpha pots for more clearance (just use one half), though the lugs aren't as strong.

[Ge_Whiz]

Gez, I agree that those pots have a nice feel to them. I tend to use them by default these days as I have found them to be very reliable. Another nice feature is that they are small laterally - if you buy the small die-cast boxes from Rapid you can fit three of those pots alongside each other without crowding, as I did for my 'Odie' build. Also, being of square cross-section, when placed alongside each other like this, each prevents the adjacent ones from rotating, so no locking lugs are needed.

[bwanasonic]

That looks like a cool mounting technique. Maybe it's time to get over my bias against plastic pots/shafts. How do ensure your drilled holes line up with the pots? I would most likely want to mount them the reverse of the way shown, with the part side away from the shafts, so twiddling trimpots is easier with the pedal assembled.

Kerry M

[gez]

I would most likely want to mount them the reverse of the way shown, with the part side away from the shafts, so twiddling trimpots is easier with the pedal assembled

B*llocks, why didn't I think of that?!!    That's a really good idea and would be easy to do too, just bend the pins the other way and flip the board round.  I wouldn't have had to bother laying the large caps on their side as there would have been plenty of headroom for the components.  Thanks Kerry!!!

I just use a template to drill holes.  Stick it on with masking tape, drill a guide hole with the bench drill then go for the crunch with a unibit.  There's a bit of leeway as the pot's pins will bend a little if you're slightly out.

[gez]

Double b*llocks!  It would help if I got the name of the product right too wouldn't it?!  :oops:  It's Omeg.

http://www.omeg.co.uk/products.htm

I'll edit the first post...

USA distributor here Jason:

http://www.omeg.co.uk/usa.htm

If you go to their website there's a list of regional distributors/stores

[maximee]

that's quite sexy
and this also means LESS CABLES!!!

[gez]

and this also means LESS CABLES!!!

It makes life a lot easier I can tell you!    Very neat inside the box and a lot less work.