[Rochey]

Do any of you guys know how to add a standoff to the backside of a front panel, without drilling through the entire front panel?

To explain - I have a PCB with a bunch of switches on it. The PCB needs to be exactly 12mm from the front panel for the switch-caps to fit nicely etc. I have 12mm M3 standoffs. All good so far.

On prototypes, I've simply drilled M3 size holes through the front panel, put a screw through the front to the header to hold the PCB. lovely jubbley.

I was wondering if there's something like "blind screw headers" or something I could find.. maybe partially drill a hole into the front panel, add a thread etc.

Any ideas?

Cheers

Rochey

[Ethan]

Google for "blind self-clinching standoff"

PEM makes them.

[12volts]

Google PEM. They have a fantastic range of sheet fasteners.

Frank B.

[Harpo]

The PCB needs to be exactly 12mm from the front panel for the switch-caps to fit nicely etc. I have 12mm M3 standoffs. All good so far.

or probably even more exactly, 15mm minus frontpanel thickness ...
Look out for self-clinching nuts.

[Paultec]

Find somebody with a stud welder or buy one....not that pricey.

Regards

Paul

[rob_gould]

Google for "blind self-clinching standoff"

PEM makes them.

This is really interesting. I have one question though. I found a site which describes the use of this type of fastener, but specifies that you need  an anvil and a press to get the head of the standoff flush with the panel.  But it doesn't specify the tool needed for this.  How much force is required? Would a smack with a lump hammer do the trick? Or would a hydraulic press or similar be needed to deliver the required pressure?

Cheers!

[[silent:arts]]

how NRGrecording is doing it:

[Ptownkid]

it can be done with an arbour press...but you may have to make your own anvil(s)

[zayance]

a couple of months ago, i was discussing this with [email protected] actually, and getting some toughts...
Here are the big lines of the discussion:

Having threaded bolts at the backside only works with at least 4mm material thickness and either me or schaeffer can't guarantee that you will not see any deformation at the frontpanel! Silver anodized aluminum is even more sensitive for this.

Just use a countersink and standard screws and you will not have any problems. Just like SPL did it to fix the pcb where the kingbright meter are soldered to:
http://spl.info/fileadmin/user_upload/fotos/DynaMaxx_front.jpg

I think the simple hex flat head screw option is still very clean, and can save the headache.

If this can help?

[sahib]

Google for "blind self-clinching standoff"

PEM makes them.

This is really interesting. I have one question though. I found a site which describes the use of this type of fastener, but specifies that you need  an anvil and a press to get the head of the standoff flush with the panel.  But it doesn't specify the tool needed for this.  How much force is required? Would a smack with a lump hammer do the trick? Or would a hydraulic press or similar be needed to deliver the required pressure?

Cheers!

Definitely not hammer. A hydraulic press will also be like cracking a walnut with a sledge hammer.

A vice with sufficiently large jaw will do the job. Alternatively you can use a G clamp.

[juniorhifikit]

To explain - I have a PCB with a bunch of switches on it. The PCB needs to be exactly 12mm from the front panel for the switch-caps to fit nicely etc. I have 12mm M3 standoffs. All good so far

Having threaded bolts at the backside only works with at least 4mm material thickness and either me or schaeffer can't guarantee that you will not see any deformation at the frontpanel! Silver anodized aluminum is even more sensitive for this.

I just had the same issue for the same situation, and the same response from Tat, who is doing some cases for me.  We decided to do two front panels - an inner and an outer.  The inside steel panel doesn't extend out to the rack ears, and holds all of the reverse-mounted screws/bushings for pcb mounting (this can be ugly as it's unseen).  The outside aluminum panel which has only switch holes and graphics covers the inner panel (looks very pretty) and functions as the rack ears.

[rob_gould]

Ah OK - so this will not work for my needs anyway.  I would like to have the standoffs mounted to the base of the case so that the PCBs can be directly mounted to them, as per the 51X PSU.

The bottom panel of most cases is nowhere near 4mm thick...

[mitsos]

Rob, they're talking about threaded studs, not nuts.

PEM nuts should work fine.  I use something similar, though I have it done for me, because I don't have the patience for metal work.  Just make sure to get the right ones for the panel material/thickness. You need to drill a hole of the proper diameter (check the nut data sheet) and press it in.   

For behind front panels, wouldn't welded nuts avoid the front deformation?

[0dbfs]

This stuff:


Makes a very tight bond.
Probably works great for proto's.
I have used this to repair shockmounts that were originally welded and they have stayed solid after months of regular (daily) use. I don't know about 20+ years of heavy duty service though.

Cheers,
jb

[rob_gould]

I am going to give this a go I reckon.

I'll start by trying to use a G clamp with a deep throat to insert the standoffs :

http://www.ebay.co.uk/itm/Faithfull-G-Clamp-Deep-Throat-200mm-8-inch-Cap-85mm-3-inch-/230707206732?pt=UK_Hand_Tools_Equipment&hash=item35b7389a4c

If that doesn't work, small arbor presses are pretty cheap and will do the job.

The only thing I'll need to work out is how to make an anvil.  A cylindrical piece of iron with an appropriately sized hole drilled into it would do the trick for m3x6 standoffs I reckon. 

[Paultec]

You English people add sexual innuendo to everything....

 

[Dan Kennedy]

Almost all of the Great River panels have PEMs pressed into the backsides.

If you're doing small quantities use an arbor press, or a light hydraulic press and
use an aluminum anvil to press against, this saves marring the front.

I usually use 3/16" panels,  never had any problems.

[zayance]

Hi Guys, i got myself a couple of samples of the PEM Standoffs (M3 Steel/Stainless Steel 6mm High), too bad i didn't get samples for the Nuts could have been nice to try it out also .
Anyway did myself a small anvil and press (thanks to my buddy who has all those fancy tools), these are fitted between a Vice and so to try on different Material and thickness.
A Vice gives some good amount of pressure but got to say it's pretty easy with some simple tools, and doesn't require much "human" force, a little more on the Steel of 1.5mm but not that much, Of course you need those Press and Anvil flat and parralel as possible, but compared to the fancy Industrial tool, it's pretty much ghetto here, in comparison the depth of action is of course limited when using a vice, but i was curious of how all this goes, and maybe will jump on an Arbor press? One with some depth tough.
Will maybe add magnet behind the anvil and press to keep them in place while using the Vice, got to try that as well.
The Blind Inserts would be a little more tricky, because you need to have a blinded hole as well etc...
And of course for simple standoff, a hole and a screw will make the same. But the Nuts insert might be handy, But PEM's are nice stuff.


Couple of pics:

L > R     Steel 1.5mm/Aluminium 1mm/Steel 1mm





Back of the 1mm Steel sheet, pretty clean.



1.5mm Steel (steel standoff and Stainless Steel)



Aluminium 1mm, a little more rough finish, but i did it quicko and the hole was maybe a little more "dirty"

[rob_gould]

Nice!

It's good that you were able to have the anvil custom made.  That is the main thing that prevents me from trying out this technique.

The other is that PEM fasteners don't seem to have a supplier in the UK.  Perhaps I'll also try and get a few samples...

One question - I see of course why you used the anvil, but why the other metal tube ( I think it is what you call the press)?  Surely if you padded your vice appropriately, the press would not be necessary.  Or have I misunderstood?

And sorry again for the stoopid question, but I don't understand why blind standoffs would be more tricky.  You just drill the hole for the blind standoff in the same way as the hole for a normal standoff don't you?

Cheers

Rob

[zayance]

It's good that you were able to have the anvil custom made.  That is the main thing that prevents me from trying out this technique.

Maybe could ask Stewart (Zebra50) if he can help you out?

The other is that PEM fasteners don't seem to have a supplier in the UK.  Perhaps I'll also try and get a few samples...

There is, here is one of them
http://www.zygology.com/ProductCart/pc/WEB_page.asp?ID=1

One question - I see of course why you used the anvil, but why the other metal tube ( I think it is what you call the press)?  Surely if you padded your vice appropriately, the press would not be necessary.  Or have I misunderstood?

The anvil and press is made of a steel bar of 12mm, and i think having both is good for making the insert beeing well fitted in there, if you check their industrial machines you'll see that it's the same principle, i made the Anvil a little rounded, to make less contact with the material, and the other is as flat as possible, both apply a nice pressure on the insert.
And when i had the inserts in hands, wich is pretty small, the side that gets into the material is very thin, maybe 0.5mm, and so i think having the other press hard and flat enough is better.
Now if working only with aluminium sheet, maybe don't even need the anvil and press made of steel, but aluminium could do.
But if going in steel and thicker ones than forget it, after some time the presse will get the insert mark and will not be efficient no more...

http://www.pemnet.com/presses/4_spec.html

And sorry again for the stoopid question, but I don't understand why blind standoffs would be more tricky.  You just drill the hole for the blind standoff in the same way as the hole for a normal standoff don't you?

I said blinded hole as on an fpd, since you don't have to drill using a simple V shaped bit, but need a milling bit, to get your hole
as flat as possible, and also need to make sure that the depth of the drill to not get thru it.
Possible, but a little more tricky, than just drilling a hole, put the insert, press and voila....
Next think i'm going to try is insert in PCB's....


Hope this helps?

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