Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case
you want see what I have in mind), and I need to put the trapezoidal
hole in one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to
machine something that has non-orthogonal sides. One approach would be
to put the rotary base back on my vice. I could make a jig of some
sort, or simply get the corners right and fake the non-parallel edges.
Given that I have previously done this by hand with a dremel, it need
not be perfect. With that said, suggestions for doing it correctly will
be cheerfully read and quite possible used.

Bill

Just a WAG here, but how about using a shaped wooden block for a
backer? I've done similar things for routing thin wood and the like.
You might even want to use a trim router and a template. We used to
use routers for cutting aluminum/foam/wood stringer/panel sandwiches
for putting windows in motor homes, so routing even aluminum panels
with wood-working tools is possible. Hot melt glue is a perennial
favorite for temporary fixturing in the woodworking world, might be
that would help, too.

Stan

"Bill Schwab" wrote
I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
....snip
Obviously, once I clamp the box, I will have the joys of trying to machine
something that has non-orthogonal sides.

Bill, FWIW, a rectangular hole with work with D-Sub connectors. It's not
quite as pleasingly "perfect" as a trapezoid, but the holes still have
enough material to grab, if you back up the studs with small washers.

LLoyd

Clamp it in the vise with the opening toward you and maybe some
cardboard between the box and the jaws. If you are worried about
clamping pressure put a block of wood in the box so you are clamping
only the bottom and a parallel or such behind it if it has molded feet.
Mill it with a 1/8" bit at the highest speed. I'd mill it square and
file the longer side. The mounting holes can be milled out from the
opening or drilled separately.

Size the hole for the male connector regardless of which one goes on
the box.

jw

On Tue, 01 Nov 2005 15:55:21 -0500, Bill Schwab
wrote:

Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case
you want see what I have in mind), and I need to put the trapezoidal
hole in one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to
machine something that has non-orthogonal sides. One approach would be
to put the rotary base back on my vice. I could make a jig of some
sort, or simply get the corners right and fake the non-parallel edges.
Given that I have previously done this by hand with a dremel, it need
not be perfect. With that said, suggestions for doing it correctly will
be cheerfully read and quite possible used.

Bill


Hey Bill,

Yep, pretty tough to work on a plastic thingy at some distance above
the chuck jaws, if I read you right. I think I would forget the vise
altogether.
1. I'd start with a decent size hunk of scrap 3/4" plywood, maybe
about 6" wide by 8" long or so (width to suit Step 4.)
2. Screw a block of 2 X 2 X the-inside-width-of-the-box, on the
face of the ply crossways at one end.
3. Bore out a couple of 1" holes just below the 2X2 to allow 3"
C-clamps a reach in and so the C-clamp can sit on the "bottom" of the
2X2 (in Step 5.)
4. Allowing for the C-clamps, fasten the ply (more C-clamps??) to an
angle bracket on the mill table, with the 2X2 up and away from the
angle plate and parallel to the mill table.
5. Clamp the end of the box to be cut onto the 2X2 with C-clamps.

If you do a bit of fiddle with the sizes beforehand, you can probably
also clamp the "bottom" of the box onto the 2X2 also.

Take care.

Brian Lawson,
Bothwell, Ontario.

I machine cases like that all the time on my mill. Get an angle plate tall
enough that the whole case can fit on the upright part of the plate, mount
the plate on the table and clamp the box to the plate. www.use-enco.com or
similar suppliers sell angle plates pretty cheap if you don't mind the cheap
and probably radioactive chinese cast iron. If you have to do a lot of these
boxes, drill holes through the plate that line up with the holes for the
case cover, and instead of clamping the case screw it to the plate from the
backside.

I just use a 3/8" endmill to make a slot for d-sub connectors, as follows.

Drill the screw holes for the D-sub connector first. Then use a 3/8"
endmill, centered on the screw holes, and mill a slot up to about 0.050" of
the holes.

Low cost import d-sub "Greenlee" style punches are also available if you
shop around a little.

Good luck-

Paul T.

Bill Schwab wrote:
Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case
you want see what I have in mind), and I need to put the trapezoidal
hole in one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to
machine something that has non-orthogonal sides. One approach would be
to put the rotary base back on my vice. I could make a jig of some
sort, or simply get the corners right and fake the non-parallel edges.
Given that I have previously done this by hand with a dremel, it need
not be perfect. With that said, suggestions for doing it correctly will
be cheerfully read and quite possible used.

Bill
If the connector has a metal shell, and the box is plastic, just buy an
extra connector, heat it up with a torch, and push it thru the plastic
while the connector is still hot.

Lloyd,

Bill, FWIW, a rectangular hole with work with D-Sub connectors. It's not
quite as pleasingly "perfect" as a trapezoid, but the holes still have
enough material to grab, if you back up the studs with small washers.

Thanks for mentioning it!

Bill

Jim,

Clamp it in the vise with the opening toward you and maybe some
cardboard between the box and the jaws. If you are worried about
clamping pressure put a block of wood in the box so you are clamping
only the bottom and a parallel or such behind it if it has molded feet.

It does have small feet that would cause problems, so the parallel
sounds like a good idea. Is the opening facing me for visibility or is
there more to it?


Size the hole for the male connector regardless of which one goes on
the box.

Just out of curiosity, what is the reason for doing that?

Thanks!!

Bill

On Tue, 01 Nov 2005 18:05:42 -0500, Bill Schwab wrote:

Can we go back to the radioactive part? =:0 Do I need to borrow a
counter and go over my mill? I read some interesting cautions about
buying machine tools, but this was not on the list.

If you were near Milwaukee I'd let you borrow mine. Your address
implies that you're not...then again, my address implies I'm in Germany,
so...

Low cost import d-sub "Greenlee" style punches are also available if you
shop around a little.

No offense to the company, I hadn't noticed that low-cost and Greenlee
went together I will take another look, because it would be an
efficient way to make these holes.

You'll never be unhappy with a Greenlee punch. It only hurts when you
pay for it, but like any other good tool, it's a pleasure to have and
use. That said, if you're only making a few, ...

Bill Schwab wrote:

Size the hole for the male connector regardless of which one goes on
the box.


Just out of curiosity, what is the reason for doing that?

Because if you make the opening to just fit
the female connector, the male won't seat
all the way. And yes, I did make that mistake
once....

Paul,

I machine cases like that all the time on my mill. Get an angle plate tall
enough that the whole case can fit on the upright part of the plate, mount
the plate on the table and clamp the box to the plate. www.use-enco.com or
similar suppliers sell angle plates pretty cheap if you don't mind the cheap
and probably radioactive chinese cast iron.

Can we go back to the radioactive part? =:0 Do I need to borrow a
counter and go over my mill? I read some interesting cautions about
buying machine tools, but this was not on the list.


If you have to do a lot of these
boxes, drill holes through the plate that line up with the holes for the
case cover, and instead of clamping the case screw it to the plate from the
backside.

Nice! I don't have to do many right now, but I will keep that one in mind.


I just use a 3/8" endmill to make a slot for d-sub connectors, as follows.

Drill the screw holes for the D-sub connector first. Then use a 3/8"
endmill, centered on the screw holes, and mill a slot up to about 0.050" of
the holes.

Does the remaining material serve an important purpose? As Lloyd
pointed out, the holes sometimes communicate with the opening.


Low cost import d-sub "Greenlee" style punches are also available if you
shop around a little.

No offense to the company, I hadn't noticed that low-cost and Greenlee
went together I will take another look, because it would be an
efficient way to make these holes.

Thanks!

Bill

"Bill Schwab" wrote in message
...
Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case you
want see what I have in mind), and I need to put the trapezoidal hole in
one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to machine
something that has non-orthogonal sides. One approach would be to put the
rotary base back on my vice. I could make a jig of some sort, or simply
get the corners right and fake the non-parallel edges. Given that I have
previously done this by hand with a dremel, it need not be perfect. With
that said, suggestions for doing it correctly will be cheerfully read and
quite possible used.


I'd be inclined to clamp it directly to the table and use some blocks of
scrap and machinist jacks inside the case to support the top solidly. That
general idea seemed to work well for some rectangular openings I milled in a
12" Hoffman box a while back.

Here's a pictu

http://member.newsguy.com/~mphenry/S...osureSlots.JPG

The metal box was just barely rigid enough that the internal support was not
needed, though there was a bit of chatter during the cut.

I'd probably also try milling a rectangular opening and then file the angled
corners - shouldn't take long with plastic.

Mike

According to Mike Henry :

"Bill Schwab" wrote in message
...
Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case you
want see what I have in mind), and I need to put the trapezoidal hole in
one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Yes -- D-shaped Greenlee chassis punches are only nice if you
have them. Also -- some plastics might shatter on an attempt to punch
them with such a tool.

Obviously, once I clamp the box, I will have the joys of trying to machine
something that has non-orthogonal sides. One approach would be to put the
rotary base back on my vice. I could make a jig of some sort, or simply
get the corners right and fake the non-parallel edges. Given that I have
previously done this by hand with a dremel, it need not be perfect. With
that said, suggestions for doing it correctly will be cheerfully read and
quite possible used.


I'd be inclined to clamp it directly to the table and use some blocks of
scrap and machinist jacks inside the case to support the top solidly. That
general idea seemed to work well for some rectangular openings I milled in a
12" Hoffman box a while back.

Since this is plastic, I think that what I would do is to take
some sacrificial lumber -- perhaps a chunk of 4x4 cut to near length, and
put it inside the box to fully support the surface which you are
cutting. Then put some straps of metal or more (thinner -- say perhaps
1/2" thick) wood on top, and apply the hold-down clamps to that surface.

Then mill through the top wood, the plastic, and a little way
into the support wood, and you should have the plastic fairly well
supported and unlikely to crack. If the position of the hole is not too
critical, draw it out on the top piece of wood, and mill to that line.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Is this for just a few D-connector slots in a plastic box? Many
suggestions here are way too time consuming, I could file the slot in
less time than one requires to locate the T-nuts and clamps for the
milling job. I'd use a 1/8 round saw file, these have very coarse grit
teeth and are bendable rather than brittle like ordinary files.

OK, you have plenty of time? Find a CNC mill and write a program to
mill the slot :-)

Klaus

It does have small feet that would cause problems, so the parallel
sounds like a good idea. Is the opening facing me for visibility or is

there more to it?

Visibility and convenience. I've tried the methods other posters
suggested and use the angle block and plywood for larger boxes but for
the small one you have a 2X4 spacer in the box should be enough. You
need to see that the wood doesn't touch the lower corner of the box
when you tighten the vise, and it's easier to add a C-clamp or 2 for
extra stiffness near the cut when you can see the upper edge of the
wooden block.

I generally saw/nibble/plasma a large opening in the chassis and make a
separate bolt-on control panel out of 0.062 aluminum. Flat panels are
MUCH easier to fabricate. Make sure the wired panel will pass through
the hole.

jw

"Bill Schwab" wrote in message
...
Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
(snip)

Bill,

Don't you just hate it when people post an answer to the question you didn't
ask?
Here's another one.

I've had good luck in the past (for short runs) by using woodworking
techniques.

1. Router template method.
Make a template out of wood that is the size of your box plus connector hole
in each dimension. So, if the box side is 3" wide, and the connector is one
inch,
make it 4" wide. Box side 2" high, connector 3/8" high, make template 2
3/8".
Offset template as required for positioning. (If you want to get fancy, you
can
put in a taper.) Cutting carefully with a jigsaw is fine for the template.
(Of course, check my math -- haven't had enough coffee yet...)

Then chuck a 1/8" end mill in a Dremel tool collet with tool mounted in
their little
drill press, plunge in, lock down, and, by hand, move the box around the
borders of the template.
Be sure to keep control of vertical/horizontal alignment. (Don't use a
chuck for this,
stay with the collets.)

This is too much work for one. It's appropriate for 10-100. It's
inappropriate for thousands.

2. Guide method.

Similar to above, but I use a metal stamping recovered from a junked PC. It
has D9,
D25, and a couple other shapes already on it. Place where required, and
mark your
mounting holes only. Drill 'em out, then mount the steel pattern (oh, yeah,
you have
to find one. But it's not hard to come up with one...) up to your mounting
holes,
raising it off the surface by about 1/4" by using nylon spacers. Then, take
your
Dremel and end mill, (freehand or with drill press) plunge it in and trace
around
the guide. Make sure the cutting edge of the endmill stays in the plastic,
and that
the shaft only of the endmill contacts the metal guide. Trace around the
guide in
the appropriate direction (this will be immediately obvious) 'til you're
done.
It's sort of like cutting out outlet holes in drywall. And about as messy.

Reasonable effort for a one-off. Acceptable for 10, but too picky for 100.

3. Re-design the whole thing....

Last time I did this in quantity, we used a Panduit box with free-floating
ends.
The front was an IR red translucent thing, but the back had a bunch of
connectors
and labels on it. We ended up going to a plastic badge engraver, and having
them
label everything, and cut out the D9 and D25 holes by just "engraving too
deep"
and popping out the waste. The badge material was fine for the back panel.


There. Three answers to the question you didn't ask.
My work is done here.

Best o' luck

"Chip" in Columbus

On Tue, 01 Nov 2005 15:55:21 -0500, Bill Schwab
wrote:

Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case
you want see what I have in mind), and I need to put the trapezoidal
hole in one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to
machine something that has non-orthogonal sides. One approach would be
to put the rotary base back on my vice. I could make a jig of some
sort, or simply get the corners right and fake the non-parallel edges.
Given that I have previously done this by hand with a dremel, it need
not be perfect. With that said, suggestions for doing it correctly will
be cheerfully read and quite possible used.

Bill

Easy. Just find or make a piece of wood that fits inside the box.
Clamp the fact to be milled to the piece of wood with at least two
clamps. I use small Kant-twist clamps for this. Grab the wood in
the mill vise. You'll mill thru the plastic into the wood a little.

For trapezoidal D-sub holes, don't try to mill the trapezoid. Just
mill straight ends, then run the mill far enough to make the wider
corners, using an endmil of radius similar to the radii of the
corners. You can then easily file away the remaining plastic to
make the trapezoid.

Jim,

Visibility and convenience. I've tried the methods other posters
suggested and use the angle block and plywood for larger boxes but for
the small one you have a 2X4 spacer in the box should be enough. You
need to see that the wood doesn't touch the lower corner of the box
when you tighten the vise, and it's easier to add a C-clamp or 2 for
extra stiffness near the cut when you can see the upper edge of the
wooden block.

Got it - thanks.

I generally saw/nibble/plasma a large opening in the chassis and make a
separate bolt-on control panel out of 0.062 aluminum. Flat panels are
MUCH easier to fabricate. Make sure the wired panel will pass through
the hole.

That's an interesting idea, especially for a future D-shell problem that
will hopefully surface. There I would be making several units with
multiple ports. As that design evolves, I will have a better idea of
how many different types of holes will be required, and that will help
me decide whether punches make financial and political sense.

With your .062 panels, could I reasonably expect to drill and bolt
several of them to mill at one time? What I have in mind is to drill
holes and bolt to maintain alignment, and then clamp the stack over
plywood or something, probably moving clamps around (add one then remove
another to make way for the endmill/bit) as work progresses.

Then I guess there is a question about whether the alignment holes
can/should be the mounting holes. Confused by what I mean? That makes
two of us With the understanding that I am trying to maintain
precision largely for practice, I am not sure I would be able to drill
the holes add the bolts w/o losing the setup[*]. If a first set of
alignment holes are drilled in margin to be removed later, then I could
stack, drill, bolt, clamp, and then mill a clean edge, drill mounting
holes, and mill the ports/slots. Clamps come off, more bolts in the
mounting holes, remove the bolts in the scrap, clamp, dial the clean
edge to re-align and then clean up the other three edges. If the panels
are small enough, they might be squared up in the vice using the clean
edge as a starting point.
[*] it might be possible with enough relief in/under the plywood
support, which could have corners removed or something to make room for
fingers or a wrench to hold a nut underneath the stack.

Am I making this too complicated? Better ideas are welcome.

Bill

Hello Bill;
I have a part time gig as the machinist/metalworker for an electronics
lab, so I'm constantly cutting odd connector holes in plastic boxes,
both hard plastics (grey FRP, like Hoffman enclosures) and soft
plastics (Pelican cases).
Personally, I wouldn't waste your time setting it up on a mill. It's
hardly worth the trouble trying to get the box mounted stable and
level. I usually just do a hand layout of the connector pattern with a
scriber, right on the box. Use an electric drill to make a few small
holes to take most of the material out of the hole, then clean it up
with a couple of small files. With a little care on the layout, it'll
be neat and sufficiently accurate.

If you're going to do multiple connector holes of something common like
a D-sub, use your mill to machine up a pattern out of 1/8" aluminum.
With that, you can quickly and consistently center punch the screw hole
locations and scribe the opening outline. I have a bunch of patterns
for the connectors that we most commonly use.

I hope this helps!

Bruce Johnson

Shear a bunch to size, drill the corner holes, bolt the stack together,
mill the rest of the features on parallels in the vise. If you don't
have a good shear, clamp the stack and mill the long edges first.

jw

Hoffman box - Yep - worked on my 24x24x12 this afternoon - drilling with a
step drill - and a hammer drill to dive it - then on the larger square and round
holes - saber saw with a metal blade and a little lube. Use large half round files
to clean up the edges to match dimensions. Three meters, two large breakers,
power plugs......

Never thought of the mill - I was wishing I could just cut it with a plasma torch -
but I figured the mess would be the larger job.

I'm almost done cutting - almost time to mount stuff and assemble the internal
plate while the box is on the wall.

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Mike Henry wrote:
"Bill Schwab" wrote in message
...

Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case you
want see what I have in mind), and I need to put the trapezoidal hole in
one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to machine
something that has non-orthogonal sides. One approach would be to put the
rotary base back on my vice. I could make a jig of some sort, or simply
get the corners right and fake the non-parallel edges. Given that I have
previously done this by hand with a dremel, it need not be perfect. With
that said, suggestions for doing it correctly will be cheerfully read and
quite possible used.



I'd be inclined to clamp it directly to the table and use some blocks of
scrap and machinist jacks inside the case to support the top solidly. That
general idea seemed to work well for some rectangular openings I milled in a
12" Hoffman box a while back.

Here's a pictu

http://member.newsguy.com/~mphenry/S...osureSlots.JPG

The metal box was just barely rigid enough that the internal support was not
needed, though there was a bit of chatter during the cut.

I'd probably also try milling a rectangular opening and then file the angled
corners - shouldn't take long with plastic.

Mike



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