[eagle] Re: 125x180 Module Assembly

Chuck Green greencl at mindspring.com
Wed Oct 17 10:10:50 PDT 2007


Hi Dick,

Lou raises a good point.  It would be nice to be able to remove the 
cover without removing the entire module.  I've been sitting here trying 
to remember those times when we had to do tests on modules already 
mounted in the P3D satellite.  There were a few times but I don't recall 
all that many.  Further, most of the times I recall, we had to remove 
the module anyway to get to the bottom of the PCB for probing.  In your 
new design, not only would the module have to be removed but the PCB 
would have to be removed from the module to get to the bottom side.  
Still, the extra rigidity seems worth these restrictions.  And with this 
design, there is no chance that the module you want into has another 
module stacked on top of it.

Although a smaller satellite, AO-51 not only had to have the PCB removed 
from the module to get to it's bottom, but you had to completely 
disassemble the entire satellite to get to the bottom module, something 
I had to do just a couple of days before we transported it to the launch 
site.  I didn't like it, but in the end it really wasn't all that big a 
deal.

And the more I think about it, the more I like having the PCB extend 
over the sides of the frame.  This would be difficult to do if you 
change the way the lid is mounted.

Finally, you don't show any measurements.  I need to go out later today 
and buy an electric oven for curing conformal coatings on widgets for 
P3E.  I'd like to get one big enough to hold the proposed maximum board 
size(s).  I don't need exact measurements, but can you tell me something 
close?

Another "finally," did you make any measurements of Sub-D and SMA 
connectors to see that they can be mounted to the front bracket and into 
the PCB without their pins shorting to the base plate?  Your drawing 
looks like this could be a problem.

Chuck

Louis McFadin wrote:
> My comment on this is that the way the housing is fastened on by 
> screws on the side will present a problem and more or less remove most 
> of the advantage of having a removable cover. If the module is mounted 
> in the spacecraft and you need to remove the cover for a test or 
> adjustment, You have to remove the module first since access to the 
> screws on the side is blocked by adjacent boxes.
> It would be better if you could remove the cover by accessing from the 
> top some way. Perhaps a top hat profile would be better.
>
> Lou McFadin
>
> W5DID
>
> w5did at mac.com <mailto:w5did at mac.com>
>
>
>
> On Oct 16, 2007, at 3:46 PM, Dick Jansson-rr wrote:
>
>> Bob:
>>
>>  
>>
>> Attached are three pdf views of the proposed revised Eagle module, 
>> and open view, fully closed view, and a view w/o the PCB. It has been 
>> a lengthy day getting all of the darned 0.5mm cover bends correct and 
>> holes properly placed for full mating of the cover with the baseplate 
>> (such things as 0.581mm hole placement discrepancies – ugh!). If 
>> built from the drawings that can be made from these objects, there 
>> should be a good fit in the real hardware.
>>
>>  
>>
>> I do not presume as to what the “real” next step wants to be, as I do 
>> not propose to make the 2D drawings until the discussions have 
>> settled down to agree that this is what we collectively like, or at 
>> least collectively accept. Please advise.
>>
>>  
>>
>> ’73,
>>
>> Dick Jansson, KD1K
>>
>> kd1k at amsat.org <mailto:kd1k at amsat.org>
>>
>> kd1k at arrl.net <mailto:kd1k at arrl.net>
>>
>> <125x180 Module Assembly Open.pdf>
>> <125x180 Module Assembly Closed.pdf>
>> <125x180 Module Assembly w-oPCB.pdf>
>> _______________________________________________
>> Via the Eagle mailing list courtesy of AMSAT-NA
>> Eagle at amsat.org <mailto:Eagle at amsat.org>
>> http://amsat.org/mailman/listinfo/eagle
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Via the Eagle mailing list courtesy of AMSAT-NA
> Eagle at amsat.org
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>   


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