DB25 mounting panel thickness

Hi all,

I am hoping someone has some insight on a mechanical problem with a 6 way DB25 passive split I built.

I used a case from Modushop with a 3mm aluminium rear panel, which I had them cut using a FPD file.  Majestic supplied the adaptor boards, and I used these connectors (http://uk.rs-online.com/web/p/pcb-d-sub-connectors/7952318).

Now I have the problem that the connector cannot mate properly because it is stopped by the standoff. I have tried looking for shorter standoffs at all the usual suspects (mouser, rs, farnell) to no avail.

If I use machine bolts instead of standoffs I could get the connector to mate, but then it's not secured in any way.

I'm sure others on this board have encountered similar issues. Any suggestions?

Full box.

The problem!

the solution:

the fpd file (remove .brd):

Problem is because the panel is too thick.
The correct solution is to convert the holes for the standoffs as flat bottom counter-bore holes. Basically you want half of the standoffs' body buried inside the panel.

See the following photos (DB25 SUMTHING topic)
https://groupdiy.com/index.php?topic=52068.120

Thank you both for the responses. It's a shame FPD doesn't flag things like that (I used their template), but I guess that's part of the fun of metalwork!

In the hope of saving the one that I have, do you think it's possible to create metalb00b00's solution with a drill press? Any other remedial solutions?

A drill press is recommended.
For 4-40 hex standoff (1/4" width), you need a flat bottom counterbore bit with 9/32" or 5/16" cutting diameter.

http://www.harveytool.com/prod/Counterbores/Holemaking---Threading/Browse-Our-Products_274/Counterbores---Flat-Bottom_128.aspx

You might like to get a standard drill in the same diameter as the counterbore linked to.

This is because the counterbore has no pin... and you already have your smaller holes.  So, if you just go at it as-is, it will wander all over the place, and make a real mess.

If you widen the existing hole out to the same diameter as the counterbore, and then just use the counterbore to flatten off the base, then you wont have the wandering issue.

In truth, you could probably / possibly get away with just using a drill.  The base of the hole will not be flat / level, but this may well not matter, as the hex stand-off will still contact around its edge.

Sure, its not what you would do on a production job, but for a prototype etc it would be perfectly functional, and you may have the tools to hand right now?

ps.

whatever the path you take, just dont go too deep!

you can't do it with a standard drill bit, because what you'll get with it is a countersunk hole instead, and the standoff won't sit properly inside.
if worried about precision, use the one with a pilot shank matching the existing hole diameter or you can also reamer the existing hole diameter to match the pilot shank.

M4 is a suitable candidate.

http://www.ebay.com/itm/M3-M16-Straight-Shank-Flat-Counterbore-Drill-Reamer-Select-size-/272512160812?var=&hash=item3f72fd942c:m:mRyd9zydX24nq65LOzrG8Hg