Author Topic: Re-aligning a slightly crooked board mounted pot  (Read 2437 times)

Bret608

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Re-aligning a slightly crooked board mounted pot
« on: July 22, 2013, 09:25:14 AM »
Hi all,

A couple of times when using board-mounted pots, I've basically just used the drilled enclosure as a jig, which is probably what you're supposed to do!  ;)

More often though, I'm too impatient to wait for an enclosure before testing, so I use a "third hand" to hold the PCB and pot in place to solder them together. I've had good luck lining them up well enough to still fit in the enclosure fine later on.

Well, this weekend, I did this with an Egodriver board (which sounds great!). Checking the pot alignment against my drill template, I noticed I have the gain pot in slightly crooked. One of the outer pins wasn't in the hole all the way when I soldered it. The middle pin isn't totally in either as a result.

Is there a way to deal with this without desoldering the pot? Could I reheat the joint and gently push the pin into the hole better at the same time?

Thanks,

Bret

DutchMF

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #1 on: July 22, 2013, 09:56:09 AM »
Hi Bret,

I think your own suggestion of reheating the joints carefully and realigning the pot in question should work very well. To be ahead of those kind of things, I've made a bunch of these: http://www.madbeanpedals.com/forum/index.php?topic=3908.0
I've had the idea of having them cut out of sheet metal, but haven't gotten around to that...  ::)
(I just saw you responded tho this very same thread! LOL!)

Paul
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Vallhagen

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #2 on: July 22, 2013, 10:07:41 AM »
My workflow is like this:

I solder each pots middlepin (pin 2) to the PCB, and this is done with a "helping hand" and some foam or cardboard between the pot and pcb to get the right distance - not with the pcb placed in the drilled enclosure.

Then i Place the pcb (including pots) in the enclosure, and gently (only by fingers) draw the nuts. At this moment there are Always (even if small) some tensions between the pots-pcb-enclosure.

Then i solder pin 1 and 3.

Then i re-solder/re-flow pin 2. When doing this, i can almost Always see/feel a small movement of the pin in the solder hole when the solder goes fluent. Which means its a good thing to re-flow the pin, to let it find its most comfy position.

then i tighten the nuts. Done.

***

But if you want to completely populate your board without a drilled enclosure... which is a good thing from many Point of views.. testing Before boxing etc. Then i do like above^^ with the difference that i solder all pins directly, not just pin 2, and then reflow all Three pins when mounted in the enclosure.

***

The short reply to your question: Yes you can reheat the joint. And if you do, you shall (important!) always add a small amount of solder. If you Think its "overflooding", just remove some solder with some braid and resolder it.

You definately dont have to remove the whole pot.

Cheers
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Vallhagen

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Yes i still have Ble Monster pcb-s for sale!

...and checkout: https://moodysounds.se/

Bret608

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #4 on: July 22, 2013, 11:04:44 AM »
Thanks to both of you! Sounds like my thinking was fairly well on track.

Paul, I had forgotten about that thread! I should really start doing this. It's funny--the example you gave in the picture was an Egodriver, exactly what I'm dealing with now.

gtr2

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #5 on: July 22, 2013, 11:19:35 AM »
I turn the PCB component side down and just solder the pots on that side then I turn it over and solder the pins.
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DutchMF

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #6 on: July 22, 2013, 02:15:58 PM »
It's funny--the example you gave in the picture was an Egodriver, exactly what I'm dealing with now.
Thats what got me thinkin about that old thread in the first place! Great pedal, BTW!

Paul
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twin1965

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #7 on: July 22, 2013, 02:16:17 PM »
I turn the PCB component side down and just solder the pots on that side then I turn it over and solder the pins.

I do the same thing but I use a piece of cardboard between pot and pcb. I only solder the middle pin and then check the other pins to make sure they are flush against the pcb. If they're not then I re-flow the pin. I can use my fingers to press the pot into place whilst I re-flow the solder. Once everything is flush then I solder the rest of the pins. Then I turn the board around and solder on the component side.

Bret608

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Re: Re-aligning a slightly crooked board mounted pot
« Reply #8 on: July 22, 2013, 02:42:49 PM »
I turn the PCB component side down and just solder the pots on that side then I turn it over and solder the pins.

I do the same thing but I use a piece of cardboard between pot and pcb. I only solder the middle pin and then check the other pins to make sure they are flush against the pcb. If they're not then I re-flow the pin. I can use my fingers to press the pot into place whilst I re-flow the solder. Once everything is flush then I solder the rest of the pins. Then I turn the board around and solder on the component side.

That's kind of what I've been doing since reading Josh's Multiplex build guide, the only difference being I use the plastic pot covers from Small Bear to give clearance from the PCB. The reason it didn't work out so well on the Egodriver was because of the way the gain and volume pots face each other.

I'll report back on whether or not I can get it sorted out! Shouldn't be a huge problem I think.