### Author Topic: How to Read This Beaglebone Black Drawing  (Read 851 times)

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#### Mastermime

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• Posts: 314
##### How to Read This Beaglebone Black Drawing
« on: July 08, 2013, 12:16:26 PM »
Hello everyone,

I'm designing a plate with mounting holes for the Beaglebone Black and I'm having trouble identifying what dimensions pertain to what on the drawing the have provided.

Here is what I identified

Length: 3.4"
Width: 2.1"

So really what I need is the distance between holes and the hole size.  I suspect the hole size is .25" or .125", but I'm not sure which, or if its both.

Thanks

#### jwatte

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• Posts: 1,219
##### Re: How to Read This Beaglebone Black Drawing
« Reply #1 on: July 08, 2013, 03:16:51 PM »
The hole radius isn't set out at all. The left hole is 1/8" up from the bottom; the right hole is 1/4" up from the bottom.
The "R" measurements are for the rounded corners of the PCB.
If there are particular measurements you're uncertain of what they mean, you might want to mark them in red or something before posting the picture. MSPAINT for the win :-)

#### Mastermime

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• Posts: 314
##### Re: How to Read This Beaglebone Black Drawing
« Reply #2 on: July 08, 2013, 05:05:52 PM »
Oh now that you say that, I understand how the dimensions work now.
Shoot, I need the hole sizes though.  Can't find them anywhere!
Thanks again for the enlightenment Jwatte.

#### waltr

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• Posts: 1,905
##### Re: How to Read This Beaglebone Black Drawing
« Reply #3 on: July 08, 2013, 05:15:24 PM »
That is a PCB Drill Symbol diagram. Is there a Table on that drawing the gives the hole diameter for each symbol.
The four mounting holes use the 'diamond' symbol.

#### Mastermime

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• Posts: 314
##### Re: How to Read This Beaglebone Black Drawing
« Reply #4 on: July 09, 2013, 09:56:37 AM »
You're absolutely right Waltr!  Thank you.   The holes are 1/8" in diameter if anyone else is wondering

#### waltr

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##### Re: How to Read This Beaglebone Black Drawing
« Reply #5 on: July 09, 2013, 06:13:37 PM »
Ok. 1/8in holes are for #4 screws (most common is 4-40NC) in case you needed to know.

#### jwatte

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##### Re: How to Read This Beaglebone Black Drawing
« Reply #6 on: July 10, 2013, 01:58:31 PM »
Also, 1/8" holes are just the right size for clearance for M3 hardware, if you live in a civilized country or just prefer metric :-)

#### Mastermime

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• Posts: 314
##### Re: How to Read This Beaglebone Black Drawing
« Reply #7 on: July 10, 2013, 05:19:44 PM »
What exactly is M3 hardware?

#### waltr

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