DB25 cut out for PCB mounting connectors

ruffrecords

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Right angle PCB mounting DB25 connectors typically mount from behind the panel. This means that, in order to mate fully with the connector, the other half needs to be able to penetrate the panel otherwise it does not go in far enough to mate properly. For this to happen you need a slightly larger than regular cut out (by about the thickness of the mating connector housing ~1mm??). The standard front panel designer macros do not cater for this situation. Does anyone have an fpd cut out that will do the job?

Cheers

Ian
 

ruffrecords

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Thanks to Holger I have the solution. I realised it is not the size of the cut out that is the problem but the fixing screws are moved forward by the thickness of the panel. Holger's neat solution is simply to countersink them to a depth of 1.5mm which makes the effective panel thickness about 1mm which is what the connectors are designed for.

fpd file attached (extension changed to txt)

Edit: I should have said counterbored not countersunk.

Cheers

Ian
 

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efinque

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Plastic cases (front/rear panels) can be tricky to work with using certain connectors because they need to be thick enough to maintain sturdiness (ie. getting the grooves of a potentiometer through the faceplate for the nut can be hard, even after removing the excess material)

I did most of my plastic fp work with free hand which is sort of messy using a soldering iron (and it smells nasty too) by plotting a few lines with tape on the case and using a marker and a ruler measured the distances for the cut-outs, however this yields somewhat dodgy results in the long run.

Last weekend I built a small router prototype to work with wood (it works surprisingly well with engraving/cutting plastics too) :

IMG-20201003-204239.jpg


It's only capable of x/y axis (ie. perpendicular lines, so no 45deg angles or circles etc unless the workpiece is rotated) and a 30mm z axis (depth) with a work area of 160mm x 120mm (the overall footprint is 230mm x 200mm)

I added some stuff after taking the pic like clamps, a semi-disposable MDF work bed and a tool holder for hot glueing etc (the ~6mm hole for the drill bit/soldering iron gets clogged with the nozzle I have)

EDIT : it could use a ceramic/metal tool mount for the soldering iron (wood/plastic engraving).. so far I've tested it with a cordless drill using 5-6mm bits but I'm afraid they break easily when routing (I was thinking of making a larger one for a hand-held 6-8mm router but the z axis is limited to 35-55mm from the router/tool base to the workpiece with the available options on the market to avoid the tool bit from breaking, so using 18-21mm plywood it may lack somewhat in z axis)
 

ruffrecords

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How about trying it with a Dremel - they have high rpm and routing bits are available.

Cheers

Ian
 

efinque

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ruffrecords said:
How about trying it with a Dremel - they have high rpm and routing bits are available.

I was thinking of buying one back in the day.. a multi-tool like Dremel would indeed be ok for a router that size, whereas a power tool is likely too large and could damage it as it has more torque (ultimately it'd be nice to cut aluminium but I was thinking of making a large one for loudspeaker building out of plywood so it needs a working area of 1220x2440mm, I drew plans for a 500x800mm for a start as a compact woodworking router is ~200mm high on an average)

They're probably ok for PCBs and stuff too.

It's almost 15 years since I last did milling with a chisel drill (now I remember the trick is to mill at an angle towards the workpiece when doing slots which requires a slightly longer bit but the risk of breaking it is smaller)

The bit in my case would need additional horizontal support too, those Dremel bits are kind of short I guess but I could make the guide rail (=gantry in CNC slang) wider.

Sorry for the off-topic.. but I've done a cutout for a USB-A port in one of my builds (Arduino Uno-based) and it called for very precise work too although it had no screws/bolts like yours has, the PCB provided the support.

EDIT : here's a more recent pic :

IMG-20201004-104556.jpg


There are screws and pieces of wood that limit the x/y axis movement so the gantry doesn't fall/come off and to prevent milling the rail by accident which reduced the work area to 125x85mm (somewhat poor engineering on my part but I kind of saw that coming, I guess it's still useable up to 3RU)
 

ruffrecords

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I mentioned a Dremel mainly because I just got myself one for my upcoming birthday. I have been watching lots of You Tube vids and it is amazing what they can be used for.

Cheers

Ian
 

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