Mechanical question

[dhouston]

Sh1t, I'm getting too old to learn new stuff!!

At 70, I knows da feelin'. My nurse tells me the stuff falling out of my ears is earwax but I'm sure it's information overflow.

I have, for limited volume, made hardwood jigs which control the position of the object to be machined and then cut similar things by hand with a router bit in a drill press. That way, the router bit only contacts plastic. You need a stable base with a rectangular pocket (which you can assemble rather than machine) which is bigger than the fixture (securing your plastic enclosure by the dimensions of the cutout to be made. It needs a starter hole and only works for rectangular cutouts. Corners will have the radius of the router bit. You need a sturdy drill press as well - they are not designed for lateral forces like this. You can probably buy a suitable drill press or manual milling machine for much less than the cost of the Greenlee punch. (I was somewhat taken aback by its price. Way back when DIY electronics was done with tubes (probably valves to you), I had 3-4 round Greenlee punches for making holes in a sheetmetal chassis that cost very little - IIRC about $20 each.

[muddy0409]

You got 9 years on me, but I'm catchin' up!
Yeah, they were valves back then and I did spend a bit of time punching out holes for the bases, with Qmax hole punches for about 20 bucks each.
Since my last reply, I have purchased a drill press for my dremel and am looking forward to using it for this and other things.

[aratti]

You can easily obtain a metal template from an old pc. Remove the db9 connector and cut a rectangle
Containing both the db9 template plus the two fixing holes. File the boarder to have it flat.

Place your metal tamplate on your plastic case and drill the two fixing hole on the plastic, hence fix the template to
the case with two screws. Now you have the tamplate in position and strongly fixed
so you can proceed to cut the internal part and finaly file it properly till it is even with the template.

Remove the template and fix your connector.

Cheers

Al.

[dhouston]

You can easily obtain a metal template from an old pc. Remove the db9 connector and cut a rectangle
Containing both the db9 template plus the two fixing holes.

With most PCB Mount DB-9 connectors, you need a rectangular opening that encompasses the extended nuts for affixing the cable. IOW, the fixing holes are within the needed cut-out so you cannot affix the template this way.

[dhouston]

Since my last reply, I have purchased a drill press for my dremel and am looking forward to using it for this and other things.

I have a drill press for dremel which I use with a non-battery powered Dremel clone. I've used it for drilling the holes for mounting eggbeater antenna elements, using a hardwood fixture made by gluing blocks/strips together rather than machining. I did not recommend it because you might find it too wobbly for your application. However, if you can dedicate it to one application, you can probably find ways to deal with the slack.

BTW, in response to your email, you should check out the Amicus18 section of the forum here if you haven't already. It's about Crownhill's PIC based Arduino form factor (but not 100% pin compatible) products. They might be off-the-shelf solutions for your needs.

[dhouston]

One other suggestion...

I've mounted some projects with the PCB on top. That way all you need is rectangulsr notches extending down from the top of the enclosure and these are fairly easy to do manually. I cut inside the vertical edges with a hacksaw blade, flex the section to be cut out with pliers until it breaks, then file the edges, starting with rough files then finer ones. It's tedious but works for short runs and prototypes. The only drawback is you see the edge of the PCB at the top of each opening and you may need to trim any long through-hole leads.

[dhouston]

You got 9 years on me, but I'm catchin' up!

I hope to keep my lead for a good while longer.