Mechanical question

[muddy0409]

Has anyone got an idea where I can get a tool for knocking out holes for DB9 sockets.
My hand skills are not too good with drills and files so I need to use a nice chassis punch.
I did see one years ago for just this application but cannot find one anywhere. Anyone got any ideas where I can beg, borrow, steal or buy one? (this is for plastic, not metal)
I can find plenty for round holes but not for DB9 holes.

[dhouston]

I've never seen one for plastic and the ones for metal are quite costly.

An alternative might be to have the company that supplies your plastic box machine the holes. Here in the USA, I've used Polycase, designing my board to fit one of their standard boxes and having them machine them.

[kellyseye]

Unless you plan to do 'lots' of hole punching, be prepared to bone up your cutting-and-filing skills as the proper tool for punching holes is VERY expensive. Consider printing a template onto adhesive plastic sheet, using a craft knife to cut the hole in the sheet and placing the sheet over the 'dodgy' hole you cut. You can make some fairly professional finishes using this technique.

[rsocor01]

I might be wrong, but I don't think you can "punch" holes in a plastic enclosure. Like Dave said you can pay somebody to make the holes for you or you can buy your own CNC machine. There are a few members of this forum that might be able to guide you in the right direction in case you decide to get your own CNC machine.

Robert

[keithdoxey]

I made a jig for cutting connector holes in plastic panels and boxes. Mine werent for DB9 connectors they were for SCART AV Connectors which are basically rectangular but with one end at an angle.

I made the jig from MDF and made it larger than the hole required then using a router with a follow collar just ran it round the inside of the template.

[J. Mark Wolf]

The common punches for doing DB-9 openings, and others, are made by Greenlee. Google them and I'm sure you'll be aghast at the prices. I once saw a knockoff DB-9 puch that was similar, and cheaper, but can't remember who made it. Perhaps your Google search will turn it up.

In any case, I don't think they'll work on plastics either.

[Bruce]

The ones made for metal work just fine on plastic enclosure panels. I've used them. You just drill a hole in the end panel large enough to pass the bolt through.

But they are expensive, and you don't need a steel punch for plastic. If you have a local machine shop, see if they will make one for you out of aluminum. I had one made 10+ years back for knocking out DB9 holes in plastic enclosure front panels for < $50, and it looked just like the $450.00+ units you see for metal from Greenlee.

They are dirt-simple to have made in most any machine shop, and with todays economy, I'll bet you could have one made even cheaper.

If you don't want one where the pass through nut & bolt is used, have a stamp made. Place a peice of hard wood under the plastic panel, and a few taps with a hammer will do the trick.

If you want really cheap, gut a DB9 connector leaving just the metal shell. Place it on the plastic, and tap with a hammer. You'll have to do a bit of filing on the edges, but it works.

[ivanrosales]

Hmm, doing the maths, a Greenlee DB9 Panel Punch cost you more than US$650 and doesn't work on plastics, a Dremel Kit cost you US$150 and you can easily make the DB9 holes and another lot of tasks...

[dhouston]

or you can buy your own CNC machine.

Even a small, bench type milling machine with digital scales/readouts would be fine for low volume. There are some with retrofittable CNC controls as well as numerous DIY projects to add CNC to small milling machines and lathes.

[muddy0409]

I do have full Dremel kit but I would still need some sort of template made out of spring steel or similar to use with the routing bit. I have used the Dremel running along a stainless steel ruler for straight line cuts and it works fine. I s'pose I could use a mild steel template EG a DB9 plate from a PC as long as I can keep the cutting bit away from the steel so it doesn't get chewed up. I guess I am just gunna hafta beef up my hand metalworking skills. Sh1t, I'm getting too old to learn new stuff!!

[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]

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]

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]

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.

[enauman]

I made a DE9 connector punch on my CNC mill that works great on plastic. It is similar to the greenlee punch but designed for plastic. If anyone is interested, let me know.

[muddy0409]

Yes, interested. You interested in selling one?

[enauman]

Sure. It can only be used on plastic as it's not heat treated. If you give me your email address I can send you some pictures and a description.

[muddy0409]

[email protected]