[hpsdr] Roll Your own Hermes Enclosure

Mon Nov 26 02:03:03 PST 2012

  Dick,

I used the dimensions in this pdf on your site:

http://www.k9ivb.net/Hermes/Hermes%20End%20Plates%20v2.pdf

along with the document from Ian Guffick to create end plates using 
"Front Panel Designer" (free software from Front Panel Express) to order 
end plates from Front Panel Express. Ian did a great job, but I didn't 
agree with him enlarging the LAN jack cutout from the dimensions in the 
above document. He made the hole a tiny bit wider (0.3 mm), and 0.5 mm 
higher. That's not much, but the plug doesn't go through the plate 
anyway, i.e. the jack is flush with the end of the board, so the hole 
could even be a little smaller (i.e. it could actually partially cover 
the edges of the jack). Also, when making the hole 0.5 mm higher he 
didn't move the bottom down by another 0.25 mm, which is fine, but that 
means that the .5mm was all added to the top, which would expose even 
more open space above the jack.

Anyway, the changes are not that much, but I stuck with the original 
dimensions in the above document. As I mentioned, I think the dimensions 
could even be smaller, but I wouldn't raise the bottom of the hole.  I 
also stuck with the dimensions in the above pdf for the accessory port, 
although the differences were even smaller for that hole. Another change 
I made, since I was having holes milled anyway (no tool change incurred, 
so the price for rectangular led holes was just about the same as having 
them drilled), was to cut rectangular holes for the rectangular LED's, 
rather than circles. I like the way that turned out.  The biggest 
mistake I made was in countersinking the screw holes for the panels. I 
wanted the holes countersunk so that the case screws didn't stick out. I 
was a little overzealous in countersinking them, and even though Front 
Panel Express shows that the countersink winds up enlarging the drill 
hole (in the associated diagram), it didn't show a change in the drill 
hole diameter (for a #6 screw) so I missed that. So the countersinks 
were way too large for the screws that came with the case.  But it turns 
out that that was OK.  I went to Home Depot and got some brass #6-32 x 
1/2 machine screws (silver colored screws are also available). The head 
were thicker than the end plate, but since the holes were large enough 
due, the bottom of the head came through. I just used a drill press to 
make the case holes for the screws larger for only a short distance (too 
large for the screw, but wide enough to accommodate the extra screw head 
thickness). Since I was replacing the case screws with 1/2" screws I 
wasn't worried about the short space that I was losing, since there was 
plenty of thread beyond that.  It turned out that with those screws the 
screw was perfectly countersunk in the end plates, after making the 
small case adjustment (i.e. I didn't have to change anything with the 
end plate). I actually prefer how that turned out, both mechanically and 
aesthetically.

Other small mistakes that I probably would change if I did it again:

1) I made the small lettering too tightly spaced. I did that to fit 
"HEADPHONE" under the headphone jack, but I should have either gone 
smaller, abbreviated, or only used the tight spacing for that particular 
jack.

2) I may have placed the jack lettering too close to most of the holes. 
I might prefer the lettering to have been a little lower. This would 
have been particularly true if I had used any flat washers on the 
exterior SMA or power connectors.

Anyway, the cost of having them done by Front Panel Express was fairly 
high. Some money could be saved by not doing the lettering or not having 
the lettering filled. Here are some links to pictures of my finished 
Hermes case, along with the Front Panel Designer files I used. I can 
provide details about the extra jacks I used for power and PTT out if 
anyone cares. Also, I got a 20% referral discount code from Front Panel 
Express when my order was completed, that anyone can use.  Here's the 
code if anyone wants to use it: 200M6CIT. The code is good until 2/28/2013.

Pictures:

http://www.themarvins.org/hpsdr/hermesfront.jpg
http://www.themarvins.org/hpsdr/hermesback.jpg

Front Panel Designer files:

http://www.themarvins.org/hpsdr/hermesfront.fpd
http://www.themarvins.org/hpsdr/hermesback.fpd

Note that due to long exposures in bad lighting the above pictures show 
slightly different colors for the end plates, even though they are the 
same. Also, the front picture shows one led not as bright as the other.  
They are both equally bright, but one is blinking while the other is 
solid on. Since the exposure was long, the blinking led doesn't show as 
brightly.

Regards,

John
AC0ZG

P.S. If anyone chooses to either not infill their lettering or to do 
their own, please take a picture of the bare metal engraving. I'd like 
to see what the bare metal (silver) lettering would look like in 
contrast to the anodized surface. That might look good enough without 
the need for adding white (or some other color), but I'd like to see 
what it would look like for future reference.

On 11/26/2012 12:55 AM, Dick Faust wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi Tim
>
> I think if you go to Ace or True Value hardware they stock 1/4" x 
> 0.062" nylon washers [mine does].  If you get two for each SMA jack 
> you will have a nice 0.124" spacer.  The SMA's are long enough that 
> this should not affect attaching the plugs and will allow the jacks to 
> come through the front panel with out milling the case.
>
> The Hammond CAD drawings indicate that the plastic ends are 0.140" 
> thick if you can read the dwg file.  That changes the overall length 
> from 6.299" to 6.579" or 6 37/64" and my plastic ruler indicate that 
> there is plenty of room left over at the rear for nylon spacers.
>
> There are some drilling templates on the SVN courtesy of Ian Guffick 
> G7JXY.
> svn.tapr.org/repos_sdr_hpsdr/trunk/Hermes/Documentation/Hermes_Hammond_Frontpanel_Cutouts_V1.pdf 
>
>
> Dick  K9IVB
>
> Tim O'Rourke wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Finally got cold and windy enough to stay in shack for weekend and do 
>> some catching up. I had the Hammond Case already just needed end 
>> plates milled and drilled. One way to do this is put light coat of 
>> impression blue on end of jacks slide board up to back of end plate, 
>> leaves nice out line of where to drill holes. If you intend to use 
>> the plastic end rings you will need to mill .130" off of the 
>> enclosure to insure PC board matches up to back of end plates. If you 
>> do not do this and tighten up the nuts on SMA connectors one one side 
>> then the jacks on the opposite side will not extend through end 
>> plate. One solution is to not use plastic rings and all will fit.
>> If you install a power connector (I used coaxial jack) be sure you 
>> use one that installs from back side so the power lead can be short.
>> I am planning a matching small Hammond enclosure with a 26 pin 
>> connector on one end and a DB25 on the opposite end for filter 
>> control and or interface to Hercules along with RCA for external PTT 
>> for linear, Phone Jack for PTT foot switch for starters.
>> Anyone who wants Hammond enclosure shortened just send it to me and I 
>> will machine and return for cost of postage back to you. If you want 
>> end plates machined I can do that for an ice cream sandwhich! Sorry 
>> no graphics as yet.
>> Tim W4YN
>>
>> Tim O'Rourke
>> W4YN at ARRL.Net
>> Low Power Amateur Radio Rocks
>> Member of Flying Pigs,ARCI,GQRP,RSGB,ARRL Life Member
>> NHRA Life Member
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