[eagle] Re: Review

Dick Jansson-rr rjansson at cfl.rr.com
Fri Oct 19 12:20:49 PDT 2007


Chuck:

The mounting rails are just that, machined aluminum faces on the baseplate
on which the PCB is hard mounted. Unless the traces are an intentional
chassis ground connection, it would be advisable in keeping them away from
these areas. In that sense, they are hard, metallic numbers.

Dick

-----Original Message-----
From: Chuck Green [mailto:greencl at mindspring.com] 
Sent: Friday, 19 October, 2007 17.54
To: Dick Jansson-rr
Cc: 'Bob Davis'; 'AMSAT Eagle'
Subject: Re: [eagle] Review

Hi Dick,

Oops, you did say clearly that this was a PCB drawing. I was thinking it 
was a top view of the base plate. Sorry!

This leaves me with a new question... Is the clear space (126mm x 
173.6mm) an absolute number or does this allow for clearance to 
components/traces on the bottom of the PCB? In other words, do I need to 
keep electrical conductors back away from these edges (on the bottom of 
the PCB) to keep from shorting them to the mounting rails?

Chuck

Dick Jansson-rr wrote:
>
> Chuck:
>
> The E05 64 drawing is THE ACTUAL SIZE of the PCB, 140x180mm.
>
> The 0.5mm note just informs the constructor that the nearest 
> structural elements are 0.5mm from the PCB.
>
> There are NO threads on the PCB, the thru clearance holes are as shown 
> 11 each diameter 3.25mm through holes for clearance to the 4-40 
> mounting screws.
>
> The missing radius (a reason for the review drawing J ) is "2xR3.2mm"
>
> The dimensional difference in the "mounting rail" is just the way 
> things turned out. (I could say that I want good thermal conductance 
> values between the PCB and the Baseplate.) I do note that in certain 
> thermal situations, I reserve the right to add more screws along the 
> edges to insure good thermal conduction to the Baseplate. The 54mm 
> spacing here is pretty wide when we discuss good contact conductance 
> between the PCB and the Baseplate.
>
> -----Original Message-----
> From: Chuck Green [mailto:greencl at mindspring.com]
> Sent: Friday, 19 October, 2007 16.16
> To: Dick Jansson-rr
> Cc: Bob Davis; AMSAT Eagle
> Subject: Re: [eagle] Review
>
> Hi Dick,
>
> Thank you for the dimensioned drawing. I can design a PCB from this. A 
> few questions...
>
> What is the inside radius of the clear space at the rear?
>
> What is the thread of the mounting holes? Do you intent to use inserts?
>
> The actual PCB size is 139 x 179 mm. No?
>
> Why is the mounting rail a different size at the back than on the 
> sides? I don't really care what it is, just curious.
>
> Chuck
>
> Dick Jansson-rr wrote:
>
> >
>
> > Bob:
>
> >
>
> > Attached is drawing E05 64, 140x180 PCB. This is being sent out for
>
> > your review, prior to being posted on Eaglepedia. This PCB gives more
>
> > working area with fewer interruptions to the working area (just
>
> > essentially two posts). Please look at this and forward any corrective
>
> > comments.
>
> >
>
> > '73,
>
> >
>
> > Dick Jansson, KD1K
>
> >
>
> > kd1k at amsat.org <mailto:kd1k at amsat.org>
>
> >
>
> > kd1k at arrl.net <mailto:kd1k at arrl.net>
>
> >
>
> > ------------------------------------------------------------------------
>
> >
>
> > _______________________________________________
>
> > Via the Eagle mailing list courtesy of AMSAT-NA
>
> > Eagle at amsat.org
>
> > http://amsat.org/mailman/listinfo/eagle
>
> >
>




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