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Subject: Re: [motm] jack only mounting brackets.

From: media.nai@...
Date: 2003-05-05

J. Larry Hendry wrote:
>
>OK. I am a little ahead of you guys. I have been considering a new bracket
>in the Stooge bracket line that would accomplish two things.
>
>1. Hold any of the CGS PCBs and have holes to adhere to his new CGS
>standard of 6" x 1", 6" x 2" or 6" x 3" PCBs. The 6x3 PCB surface area
>would be big enough to hold any of the older CGS PCBs drilling your own PCB
>mounting holes for those older non-standard PCBs. It would be no deeper
>than a standard 4 pot short bracket (same size as full size MOTM) so that it
>will work for SKB users.

The CGS ASR PCBs are 2" x 6" each, so two of them together are 4" x 6".

>2. Mount by jacks only or a combination of jacks and maybe one pot as an
>option. I would prefer jack mounting only. Since I am not familiar with
>all of the control layouts for some of these module panels, I don't really
>have enough information to know how to do the front part of the bracket.
>However, I can assure you that 2 Switchcraft jacks (one above the other)
>have ample strength to support a Stooge bracket.

The proposed CGS ASR panel uses standard MOTM jack spacing for
uniformity and man-sized ergonomics, like a MOTM-910, but with fewer
jacks.

>There is one problem with a bracket that mounts from jacks instead of pots.
>It could end up at the "bottom" end of a panel since some modules may have
>jacks AND pots. If you use a slant cabinet, these style brackets would not
>fit on the bottom row of a slant cabinet (including my upcoming Stooge slant
>cabinets). However, they would fit in all other standard MOTM arenas. All
>straight cabinets and the upper rows of slant cabinets would be OK.

I'm confused. If these modules use pots, couldn't they just use pot brackets??

>I think this would also be a great DIY project bracket that would be great
>for holding small proto boards for DIY modules or DIY mods to existing
>modules.
>
>Feedback on the subject of a new bracket design that mounts from jacks in
>consideration of the above information would be appreciated. Try to be
>specific.

OK :)

>Drilling in the long side of a bracket is pretty easy. But drilling on the
>side that fastens behind the panel is tough. You can't get it in most drill
>presses. Hand drilling is tough.

I agree.

> > The 4 brackets you currently stock should meet most PCBs sizes
>They are just a bit short for the new CGS standard sized PCBs.

Just to recap, those are:

Short, 3 pots 3 7/8" x 4 3/8" (3.875 x 4.375)
Long. 3 pots 3 7/8" x 7 1/4" (3.875 x 7.25)
Short, 4 pots 5 1/2" x 4 3/8" (5.5 x 4.375)
Long, 4 pots 5 1/2" X 7 1/4" (5.5 x 7.25)

The CGS PCBs are 6" long, so the "Long" brackets would be long
enough, leaving 1.25" of clearance for jacks or pots.

>First: Two separate L shaped brackets, as John suggested, both the PCB
>short bracket depth. They would never actually be connected to each other.
>They would be attached separately to the front panel and each support 1/2 of
>the PCB. Then the PCB would not have metal the entire length.
>
>Another way to do it would be to have these two standard brackets that were
>the holders for PCB sized flat plates for mounting the PCBs. The "L"
>brackets would attach to the flat part of the bracket with screws. Howard U
>did one like this that mounted from jack holes. At first I thought maybe
>there was not advantage of the full size plate. But, then I thought maybe
>there would be times that the PCB would not be the right size to straddle
>the gap between the L shaped brackets.
>
>I propose that we might need 3 new pieces:
>1. L bracket with same pot hole arrangement I use today.

Did you mean to say "jack hole spacing"??

>2. L bracket with 2 jack holes on standard MOTM spacing (one above the
>other)
>3. One full size flat PCB mounting plate that could be fastened to any
>combination of L brackets IF it was needed.
>
>I know this sound like a lot. But, I am thinking this might be the one size
>fits all (or in this case 3 sizes fits all) for DIY PCBs and CGS stuff that
>some MOTMers are building.

Like Shemp, I don't think that using a PCB to straddle the brackets
is the such a good idea. Nor are three pieces fastened together with
screws nearly as stable as one solid piece of steel. So in order not
to degrade the build quality and road worthiness of the system, a
"full-sized" bracket is necessary.

Another issue is space -- a bracket mounted to a flat plate is more
than three times as thick as a bracket by itself.

So I propose two new "Larry" brackets (but feel free to call them
"Mark brackets" if something goes terribly wrong :)

1. 4" x 7 1/4", with four jack holes using standard MOTM spacing on
the 4" end. This will hold two CGS ASR PCBs, as well as many other
PCBs. Having four jack holes provides stability, even with the
option to skip one or two rows. It also allows one to be add large
PCBs, either vertically or horizontally, to existing 2U MOTM modules.

2. 1 1/2" x 4 3/8", with two jack holes, (and if possible, a pot
hole in between them). By itself, this bracket will allow one to add
small daughterboards (eg. buffers, LED drivers), either vertically or
horizontally, to 1U or 2U MOTM modules; and two or more could be used
with either jacks, pots, or a combination thereof, to mount a flat
plate, or be straddled directly a PCB.

How do you mount two CGS ASR PCBs for use with an SKB rack?? Use two
1 1/2" x 4 3/8" brackets, mounted between the two columns of jacks,
with one PCB straddling them on each side. While this isn't as
durable as a single deeper bracket, imho, anyone using SKB cases
isn't that concerned with durability :)

If someone needs a flat plate, or a shallow bracket for a special
application, then the full-sized bracket could easily be cut down
with a hack saw, cutoff wheel, tin snips, etc. Imho, pressing the 90
degree angle is what most folks can't do at home.

One very important consideration, no matter what the other dimensions
might be, is that the short end of these brackets must allow room for
an adjacent row or column of jacks. The 1.38" used for pots is too
wide for jacks.