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STICKY: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 4:53 pm
by Gert van Loo
I have taken one of the Beta boards and a digital ruler/caliper. The measurements I have taken are posted below. I can not give the measurements of the SD-card holder as the first boards are mounted with a temporary SD-card holder. We have to wait for the final one.

I have opened a new topic instead of posting the data in the various topics dealing with the casing of the raspberry-pi. I leave it up to you guy to link this post into all those posts

As usual: Not guarantees, best effort etc. The PDF is here:

http://www.scribd.com/doc/77785093

(Post edited. Hit return by accident)

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 5:45 pm
by jojopi
Interesting, thanks.

I note that your PCB measurements of 85×56 are squarer than the advertised 85.60×53.98 — and agree better with the board photos and Gerber screenshots.

Edit: though, according to your conventions it should be 56×85.

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 5:49 pm
by stormy1
Thank you!

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 5:53 pm
by Gert van Loo

Edit: though, according to your conventions it should be 56×85.



Ooops, yes you are right!

Good I put in all the disclaimers.

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 6:02 pm
by mobeyduck
looks great but im missing the highest point on the board as in total hight/max hight

it looks like 15.3 from the usb + 1.6mm from the board 16,9mm +5mm from the sd card makes it 21,9

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 6:57 pm
by Gert van Loo
mobeyduck said:


looks great but im missing the highest point on the board as in total hight/max hight

it looks like 15.3 from the usb + 1.6mm from the board 16,9mm +5mm from the sd card makes it 21,9



I know, I assumed people can add. I did not give the max. width or max. lenght either. Also with no definitive SD-card holder and not knowing if components change for the next batch all figures are indicative anyway. I suggest whoever makes a case adds some slack.

Re: Beta Boards mechanical data

Posted: Tue Jan 10, 2012 9:21 pm
by arm2
Thanks Gert.

Are the "Flange sticks out 0.6mm on all four sides" where the boards were attached to their carrier as shown in the first photo's of the PCB?

I can't see the positioning dimension for the USB sockets! Am I being stupid?

Re: Beta Boards mechanical data

Posted: Wed Jan 11, 2012 8:02 am
by Gert van Loo
arm2 said:


Thanks Gert.

Are the "Flange sticks out 0.6mm on all four sides" where the boards were attached to their carrier as shown in the first photo's of the PCB?

I can't see the positioning dimension for the USB sockets! Am I being stupid?



Yep, I missed the USB position. I have uploaded Rev1.1 with corrections.

The Flange is a where the outside of the metal USB connector case is 90 degr. folded outwards. So the bulk of the connector is 15.3 high and 13.25 wide, but at the opening it has another 0.6 mm sticking out at each of the four sides. Thus you need a hole in your case which is (15.3+0.6+0.6) x (13.25+0.6+0.6) to pass it through.

Re: Beta Boards mechanical data

Posted: Fri Jan 13, 2012 8:35 pm
by arm2
Thanks Gert, I've update the design of our cases appropriately. I'll post photos of the mock ups we've made next week.

Now that production has started can the Foundation tell us the part number of the connectors being used?

I'll track down the mechanical data and post here the information so that anyone can start making cases!

Many connectors are not going to be very different in shape and size to those used on the Beta boards, but I suspect the SD card holder will be quite different, apart from sticking out the side it is down as protruduing 5mm below the PCB, all other SD card holders I've measured are 3.0 - 3.3mm in that dimension.

Also I've picked up some samples of possible suitable materials for Mass produced cases, that I think might be of interest to the Foundation. Is there a postal address I can send them to?

Re: Beta Boards mechanical data

Posted: Wed Jan 18, 2012 12:00 am
by Borg 1.0
Gert said:


I have taken one of the Beta boards and a digital ruler/caliper.


Gert, is it possible that the PCB design file could be used to get the exact measurements, instead of the ruler/string method?

I can send the PCB file to a local CNC place for making a case. But that requires the actual PCB data, whether it's a Gerber or a PCB (Eagle, Altium, etc) file.

Instead of releasing the actual PCB data, would it be easier/safer to do a fabrication print with all the dimensions? That way, we can read the data without having access to edit/change it. Just a thought...

It's not that I don't trust your calipers, I just naturally work better with mils/thous....

Re: Beta Boards mechanical data

Posted: Wed Jan 18, 2012 12:42 am
by Gert van Loo
Although I designed the Alpha boards and was involved in the Beta re-design I do not have access to the Beta boards database. That is owned by the Raspberry-Pi foundation.

Re: Beta Boards mechanical data

Posted: Wed Jan 18, 2012 12:53 am
by liz
And unfortunately Eben and I don't have access to those files until we're back in the UK. Poke me next week and I'll try to get him to get the measurements off the datasheet.

Re: Beta Boards mechanical data

Posted: Thu Jan 19, 2012 8:46 am
by rurwin
Gert, could I ask you to take out your tape measure again?

It seems to me that for a case to hold the board securely, it will have to have a lip that the board sits on. It would be good to know how wide the lip can be. Ideally we would want the board to sit flat on it; there should be no joints or components between the lip and the board.

So we need to know the minimum clearance from the edge of the board, on the underside. (Ignoring the area around the SD socket of course.) That may not even be measurable from the schematics, because it includes the space taken by solder.

Re: Beta Boards mechanical data

Posted: Fri Jan 20, 2012 8:16 pm
by slurp
This is good to see, it'll help me start planning an interface I have in mind for a small robot.

I'd been thinking about placing mounting holes on this new board and that utilising a connector in the P2 or P3 location would make the Pi mount a little more stable. I do note that I should leave these pins isolated.

I'm guessing I can make an approximation from the Gert's drawing but it would be fantastic if Liz could include this in the publication (next week?).

Best regards,

Colin

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 3:46 am
by lanica
Made a Google Sketch-Up.  Assume the same disclaimer.  Might be easier for some to make a case using sketch-up…

Wish the board supported attachments.  Here it is for download:

http://www.filedropper.com/raspberrypi

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 3:56 am
by tzj
makes me wonder what"s wrong with 3d warehouse when sharing sketchup models...

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 5:12 am
by mspice
If we could also have a BOM with part numbers, we could model every connector very accurately.

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 9:01 am
by HansH
Ok I am lost...

Is the actual pcb   56mm  or  53.98mm width ?

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 4:37 pm
by lanica

tzj said:


makes me wonder what"s wrong with 3d warehouse when sharing sketchup models...



Likely nothing.  I'm not that experienced with Google SketchUp... Just didn't think about it I suppose.

Its in the 3D warehouse:

http://sketchup.google.com/3dw.....f459967fe5

It is also publicly editable, so feel free to update/tweak it.  If someone defaces the model then I'll turn public off and just add individuals as collaborators.

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 4:41 pm
by lanica
lanica said:



tzj said:


makes me wonder what"s wrong with 3d warehouse when sharing sketchup models...


Likely nothing.  I'm not that experienced with Google SketchUp... Just didn't think about it I suppose.

Its in the 3D warehouse:

http://sketchup.google.com/3dw.....f459967fe5

It is also publicly editable, so feel free to update/tweak it.  If someone defaces the model then I'll turn public off and just add individuals as collaborators.



Ok...looks like you had one as well ... you could have just said that   Anyone else who stumbles upon this topic, tzj has one at:

http://sketchup.google.com/3dw.....659e23ee1a

I'm assuming you posted this elsewhere in which I entirely missed....

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 6:41 pm
by Gert van Loo
rurwin said:


Gert, could I ask you to take out your tape measure again?

It seems to me that for a case to hold the board securely, it will have to have a lip that the board sits on. It would be good to know how wide the lip can be. Ideally we would want the board to sit flat on it; there should be no joints or components between the lip and the board.

So we need to know the minimum clearance from the edge of the board, on the underside. (Ignoring the area around the SD socket of course.) That may not even be measurable from the schematics, because it includes the space taken by solder.



Sorry, I did not see your post until today. I don't mind PM's as long as there are not too many.

I started measurements but I stopped after half an hour. This is significantly more complex then the connectors. There are lots of tiny components at the bottom and all kind of pieces of metal sticking out. Also some pins/metal have solder round them and the distance to the edge is set by how much solder is present.

I estimate is that you have about 1.6 mm free around the edge, except the Ethernet mechanical pin sticking out which is about 1.3.

Looks to me your best chance for support is not a ledge but some pillars at the right places. I will see what I can come up with but I would suggest you look at the photo's of the bottom, select some reasonble large flat places and put pillars there. Now you know that the PCB is 56x85 you can get the rest of the measurements from that.

Re: Beta Boards mechanical data

Posted: Sun Jan 22, 2012 9:31 pm
by rurwin
Thanks. So probably 1mm or pillars. I'll take a look at the photos.

Edit: done.

The photos of the beta boards need to be corrected for perspective before measurements can be taken from them. I have done that, and the results can be found here. I think they can be trusted to within 1mm, but no guarantees.

Edit again:

I've added some suggested support locations to the page given above. The locations I suggest only require measuring in 5mm steps, and should allow a couple of mm error.

Re: Beta Boards mechanical data

Posted: Mon Jan 23, 2012 11:52 am
by HansH
rurwin said:


Thanks. So probably 1mm or pillars. I"ll take a look at the photos.

Edit: done.

The photos of the beta boards need to be corrected for perspective before measurements can be taken from them. I have done that, and the results can be found here. I think they can be trusted to within 1mm, but no guarantees.

Edit again:

I've added some suggested support locations to the page given above. The locations I suggest only require measuring in 5mm steps, and should allow a couple of mm error.


I am not so sure about that support bridge.... depends a bit how far the SDcard will go in...

Re: Beta Boards mechanical data

Posted: Mon Jan 23, 2012 12:40 pm
by rurwin
That's a fair point. I was assuming it would come no further than the silkscreen shows it. The same technique should be useful; the bridge could be moved back about 4mm, or the pillars could be moved closer to the edge of the board by about the same amount. But those reduce the error margin and make the measurements more fiddly. We wont know if there is a problem or how to solve it until the production boards arrive, since the beta boards do not have the correct SD socket.

Re: Beta Boards mechanical data

Posted: Mon Jan 23, 2012 1:45 pm
by HansH
well, it looks like they were meaning to use something like this:

http://www.harwin.com/include/.....860942.PDF

a half length sd slot connecter, measurements seems the same as the markings

The sdcard will stick outside the pcb for approx 18mm

So your bridge is ok...