Author Topic: Layouts and hardware  (Read 586 times)

DFX

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Layouts and hardware
« on: June 21, 2019, 05:41:01 AM »
Mounting hardware to the pcb:

Anyone who does their own layouts know what you can and cant do?
eg. can the mini rotary be board mounted with a mini 3pdt?
      or mini 3pdt and 9mm pots etc etc

I just don't want to go ahead on a layout to find things don't fit.

HamSandwich

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Re: Layouts and hardware
« Reply #1 on: June 21, 2019, 07:45:56 AM »
It's all about the datasheet. Pull up the measurements of each of the components in question and see if they are within a few mm of being the same height.

aion

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Re: Layouts and hardware
« Reply #2 on: June 21, 2019, 12:32:31 PM »
I tend to mock things up in Illustrator (Inkscape may also work) - and in this situation I would create a side profile of each of the parts and see how they line up. Include all hardware like nuts & washers if they would impact the internal mounted height (for instance, a toggle switch is usually mounted with an inner nut and star washer).

You can set measurements to inches or mm and then create the shapes with the exact sizes from datasheets to make it accurate. I will also sometimes use calipers to measure a physical part if there is any doubt from the datasheet.
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Aentons

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Re: Layouts and hardware
« Reply #3 on: June 22, 2019, 12:48:31 PM »
I've been curious about a different design aspect of board mounted hardware. How do you approach how much stress you can/should put on the solder joints for knobs, switches, and pots, whether they are PCB or panel mount?

HamSandwich

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Re: Layouts and hardware
« Reply #4 on: June 23, 2019, 10:49:36 AM »
I've been curious about a different design aspect of board mounted hardware. How do you approach how much stress you can/should put on the solder joints for knobs, switches, and pots, whether they are PCB or panel mount?

The simplest way is to loosely secure  all the hardware to the enclosure, put the PCB in place, then fasten down the hardware. Finish off by soldering. Then you know it all fits without worrying too much about it. 16mm pots worry me a little bit if they need resecuring  as they seem to be the most prone to twisting when you tighten the nut down.

Thatís assuming itís all mounted on one plane. Throw in side jacks and the whole thing is a minefield

Aentons

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Re: Layouts and hardware
« Reply #5 on: June 23, 2019, 11:32:34 AM »
I think what I am mainly asking about is... how much stress can you allow on a solder joint before it becomes a bad design decision. Obviously, panel mount components are less stressful than PCB mount, but how do you know when its ok to use PCB mount?

I see PCB mount 9mm pots and power jacks  and the occasional switch. Are there any rules of thumb regarding their usage?

As an example, the pic shows the PCB mount switch on a EHX Graphic Fuzz, which is currently broken...

« Last Edit: June 23, 2019, 11:35:27 AM by Aentons »

alanp

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Re: Layouts and hardware
« Reply #6 on: June 23, 2019, 01:01:13 PM »
The simplest way is to loosely secure  all the hardware to the enclosure, put the PCB in place, then fasten down the hardware. Finish off by soldering. Then you know it all fits without worrying too much about it. 16mm pots worry me a little bit if they need resecuring  as they seem to be the most prone to twisting when you tighten the nut down.

Agreed with Ham. Where possible, I do synth panels the same way (except soldering maybe one or two jacks firmly down to hold everything else in place. Synth panels have a silly amount of pots and jacks, compared to pedals.)

Thatís assuming itís all mounted on one plane. Throw in side jacks and the whole thing is a minefield

Some advice I saw in DIYSB is to not have PCB mounted parts on more than one plane.
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aion

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Re: Layouts and hardware
« Reply #7 on: June 23, 2019, 03:22:07 PM »
Some advice I saw in DIYSB is to not have PCB mounted parts on more than one plane.

100% agree with this - unless you've got a flawless CNC machine that's accurate within mils and some killer CAD skills to program it.
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pickdropper

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Re: Layouts and hardware
« Reply #8 on: June 24, 2019, 05:22:09 PM »
Some advice I saw in DIYSB is to not have PCB mounted parts on more than one plane.

100% agree with this - unless you've got a flawless CNC machine that's accurate within mils and some killer CAD skills to program it.

Thirded.  PCB mount pots/switches on the face of the enclosure are no problem.  If possible, it's better to wire the 1/4" jacks off-board.  I strongly dislike most of the PCB-mount DC jacks as it puts continual strain on the solder joint.  I'm not a fan of board mount footswitches, either.

If you have to board mount the 1/4" sockets, I recommend overdrilling the side of the box so there's less chance of binding.  It's good advise to mount them before soldering as there is a draft to the sides of the enclosure and that can add strain as well.
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somnif

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Re: Layouts and hardware
« Reply #9 on: June 24, 2019, 05:47:34 PM »
 My trick: pizza box prototyping.

Layout all the hardware on pizza box type cardboard. It's about the same thickness as enclosure aluminum, or close enough for testing.

Once layer out, you have a "hands on" idea of whether or not the parts are close enough in height to be mounted on the board as-is, as well as whether or not knobs would be too close together for easy control.

Plus, it's cheap, and I always seem to have a pizza box or two waiting to hit the recycle bin.