How would you guys approach this?

[Toybuilder]

I am trying to make a sheetmetal plate that will hold some circuit boards. Unfortunately, one of the mounting holes which needs to be supported is located where tall components surround the hole location. (In the attached screen shot, the array of 2x4 holes on the left is populated by a big power connector).

To make things worse, the shorted component is an adjustable potentiometer (dark blue), so it has to be accessible to a small screwdriver.

I have been trying many differnt ways to get a support tab to that mount hole today, but have been unhappy with much of the results. I think what I want to do is to create a "flyover" over the potentiometer which can be done as a single bend step by putting a flange, unbending, cutting out the notch to clear the potentiometer, and rebend (per screenshot).

Does anyone here have any ideas/suggestions on this? I'm pretty stumped right now.

BTW, as it's modeled right now, the plate is 1 mm, and the height of the pot is ~ 7 mm.

 

[JordanCClark]

Well, I'd start by attaching a screen shot... :wink:

 

[Toybuilder]

Image of "flyover" attempt

Ooops. Here it is!

 

[hartlw]

The circuit board is green with holes in it. The potetiometer is blue. The flyover is white

How do you attach the potentiometer using existing holes (inaccesible in area of potentiometer) in the circuit board?
Is that the question?

As shown, it doesn't look like fly-over is a positive hold, just relying on spring pressue as you tighten screw which holds fly-over.

 

[JordanCClark]

The mounting hole is where the flyover is running to. The pot is soldered to the board. I think the question is "How can I best get sheetmetal to the mounting hole?" Yeah, it's paraphrased a bit, but I like it. :mrgreen:

EDIT: Should have said the the mounting hole is for the board, not for the pot. Sorry... just starting my coffee...

 

[DavidJ]

There used to be a fantastic example of sheet metal work in Alibre posted on the web, it was for a PC chassis or something very similar. My recollection is that the text may have been in Spanish, but there was more than enough in the pictures to work out what was happening. It covered stuff that would be very helpful for stuff like the problem above.

The only issue is I can't find the web site - can anyone else provide a link to it...?

[EDIT - I found I had left a link in an earlier post, here is the tutorial http://www.mefsimulacion.com/pdf/AlibreSpanish/tutorial/Sheetmetal.PDF]

 

[hartlw]

 

[Toybuilder]

Thanks for the responses so far. I apologize that i was not clear enough in my initial posting -- what I was attempting is to have a flyover to bring chassis sheetmetal to a mounting hole which is obstructed by tall parts all around. The potentiometer is the shortest part, and hence was selected to be "flown over" to bring the mounting tab to the hole.

I am not using the flyover to hold a part. Sorry for the confusion.

After struggling with this, I just said to heck with it and am using a threaded spacer.


But I would still love to see how to cleanly do the original approach...

 

[NateLiquidGravity]

:lol: That was my idea too.

 

[hartlw]

3 is the way to go. Simple, variable stiffness (thickness), flexible, and no moments.
And easy to make a prototype to play with.

 

[NateLiquidGravity]

hartlw: Perhaps a good solution to hold the potentiometer however the OP is trying to hold to the board from the outside sheetmetal while avoiding the potentiometer.

Toybuilder: If you wanted you could add two more bends (like a mirror of your other bends) to bring the sheetmetal to the surface. The bends would look like this.

  _  
 _| |_

However that could get in the way more when trying to install it.

 

[hartlw]

hartlw: Perhaps a good solution to hold the potentiometer however the OP is trying to hold to the board from the outside sheetmetal while avoiding the potentiometer.

????????

The u-clip is trivially obvious and woudln't work because it wouldn't put pressure on the potentiometer, and wouldn't fit anyhow.

 

[dwc]

Experience says that the electronics types making that PCB will change it every couple of weeks, at least until full production starts.
Take advantage of that and have them put the mounting hole on the other side of the poti.
It will make your part simpler and won't cost them a penny.
They will, of course, say the change is impossible, but don't believe it.
Don

 

[hartlw]

Nate, sorry. I missed the part about not touching the potentiometer. I thought the intent was to hold it down, not create a short to frame.

So the problem is short screw in motherboard to frame over potentiometer. Sure, your u-clip seems fine.

dwc: If the board is being assembled to its own chassis, then just solder a piece of wire to the frame and run it to the screw hole over the potentiometer.

 

[Toybuilder]

Experience says that the electronics types making that PCB will change it every couple of weeks, at least until full production starts.
Take advantage of that and have them put the mounting hole on the other side of the poti.
It will make your part simpler and won't cost them a penny.
They will, of course, say the change is impossible, but don't believe it.
Don

Ha ha. I am one of those electronics types! These days, it's an easier give an take between changing the electronics and changing the mechanicals -- Move a component here, move a boss there... it's all virtual! That is, until parts get made...

Which is precisely the problem -- these boards (verrry expensive boards) got made before I had a chance to check them with my "mechanicals" hat on.

BTW, Alibre is getting a good bit of attention on the Altium forum -- Altium is an electronics design package with some nice 3D enabling features added to the PCB layout editor. It has a realy nice "3D preview" feature which lets you look at, and examine, a realistic looking board populated with components, solder mask and silkscreening.