Mounting holes on R-Pi?

[nghia]

Hi,

Are there mounting holes on the final PCB? I looked the gerber that which posted by Liz but couldn't see any mounting holes.
If so, can we get the precise location of these mounting holes as well as the precise size of the board so that case can be designed?

Thanks
N.

[tntexplosivesltd]

No there aren't, it has been stated that they may be added to future releases of the R-Pi.

[Warringer]

For the moment it should be possible to solder in a pinheader to the GPIO and then place it in a socket that is either not connected to anything, or is used to power the board.

It's what I plan to do.

Take a couple of Pis, a couple of angled pinheaders, a cheap experimentation PDB, connect 5V to the pinheaders and then let the Pis rip in a small cluster.

[PiOfCube]

If anyone has a 3D printer and makes some side slotted PCB mounting brackets with screw holes, I would be interested in purchasing some. They wouldn't need to be large and you could produce them in high quantities in a single print run... I would guess at around £4 per 4 units would cover costs and allow for a little profit (of course, I'm sure a donation of some of the profits to the Raspberry Pi foundation would also be a nice gesture).

Just thinking off the top of my head here but a suggestion worth thinking about?

[Montekuri]

Read this topic: Cases for the Raspberry Pi

[tlossen]

grrr .... so, seriously, no mounting holes?!  :(

this reminds me of this superfancy trainstation which they built in germany, and totally forgot about adding toilets ....

tim

[RMW5]

The goal of the R-PI is not (necessarily) to be as small as possible, but to be as low cost a cost as possible.  I am planning to buy one to see how low cost I can go. I am not trying to be stingy for its own sake, but to see how low cost a computer really can be.

This has already meant forking out £79 for a Samsung monitor in the sale at Currys (21.5" screen HDMI/DVI/VGA). Like most monitors modern enough to have HDMI inputs it has VESA mount points, and I guess that most R-Pi users will be using a freestanding monitor on a desk not fixed to a wall (because they will have a keyboard and mouse).

To really keep the total cost of ownership of the R-PI to a minimum, it would help if instead of the current board size (85.60mm x 53.98mm x 17mm), some production boards were made with the same width as the length (85.60mm) with M4 compatible holes drilled at the corners of a 75mm square, so the cost of mounting the board on the back of the monitor comes down to a few pennies for some M4 screws and washers.

If it helps, just mark the holes and I'll drill my own.

OK, if it saves money, don't bother with the markings, just leave space on the board

[grumpyoldgit]

Looking close up at the beta boards there seem to be two holes to the left of the Raspberry logo by C5 and S2. As the board is so small I would imagine these are sufficient to anchor the board to the Ferrero Roche box of choice or perhaps a larger standard sized board that can then itself be affixed to the back of a monitor, or similar.

[RMW5]

Actually, forget it.  I can probably fix it to the back of the monitor with 4 M4 screws and some rubber bands.

[stevep]

I don"t understand the fuss about the lack of mounting holes. It should be very easy to make up some sort of mount, or to buy something suitable like this http://www.rapidonline.com/Too.....c06618d26d

[grumpyoldgit]

I was thinking along these lines!

[RMW5]

stevep said:


I don"t understand the fuss about the lack of mounting holes. It should be very easy to make up some sort of mount, or to buy something suitable like this http://www.rapidonline.com/Too.....c06618d26d


£1.04!!!.  That adds 5% to the cost.

[grumpyoldgit]

Also, with virtually every inch of the edge of the board populated with cable plugs, it's going to be tricky finding space for the tracking.

[jamesh]

Mounting holes take up a lot of board space.  A future version may have them. Or not.

[RMW5]

JamesH said:


Mounting holes take up a lot of board space.  A future version may have them. Or not.


Space is only at a premium if you are trying to get the PCB down to the size of a credit card, but why is that an issue with the R-Pi? Most of the potential users have never used a credit card.

[scep]

RMW5 said:

Space is only at a premium if you are trying to get the PCB down to the size of a credit card,
Which they were.

but why is that an issue with the R-Pi? Most of the potential users have never used a credit card.
But nearly everyone knows how big one is. It's a universal comparison and a nice PR device. They could have said that, "The Pi is the size of two Tesco milk chocolate finger bars" but this would be parochial and unhelpful

[RMW5]

scep said:


But nearly everyone knows how big one is. It's a universal comparison and a nice PR device.



The price tag is all the PR this board needs.  What it also needs is a *very* low cost way to make it usable (keyboard, mouse, monitor etc) for next to no pennies.

[Sylvain]

JamesH said:


Mounting holes take up a lot of board space.  A future version may have them. Or not.



Was the credit card size such an important thing ?

OK, it was a challenge for "you" and a waouh effect for some people, but was it really an absolute need ?

I don't say you should have done a Mini-ITX or even a Nano-ITX board but for example a board of the same size as a 2.5" hard drive (with same place for the monting holes and no protuberent connectors) should have been just ok in size and would have allow to reuse of a lot of existing thing (enclosure ...).

Or, is the size of the PCB really crucial in keeping the cost low ?

Sylvain.

[scep]

RMW5 said:


The price tag is all the PR this board needs.


A "$25 PC" sounds interesting. A "$25, credit card-sized PC" sounds like a must-have.

[liz]

Scep's absolutely right. We have to work really hard to capture the imaginations of the sort of people who are writing about us in the press, and of the sort of people who we want to buy the boards. We realised very early on that it had to have the dimensions of something whose size everybody can relate to easily; and that if that thing could be something surprisingly small, we'd have something that'd stick in the mind. I know a lot of the choices we've made on price, size and so on might feel arbitrary, but really, they're not; we have to put a lot of thought into all of this stuff!

It's also the case that silicon is expensive stuff. If we keep the area down, we save money. And that's of paramount importance here. Small is a big win for us because as well as being cute and surprising, it's also cheap.

[Nigel]

Given the range of sockets/interfaces available, I'd have thought one approach for the  enthusiast would be to permanently provide cables with suitable connectors from the sockets on the board to run to externally mounted sockets (within a case), such as the USB, Ethernet, power and video.

This way, the board could be 'free floating' off the cables given it's low weight, and more importantly, the issue of strain on the board's connectors is taken away as all cabling from external devices would plug in to the socketry on the case.

I can foresee potential future connector failures if the board sockets are directly used to repeatedly change input/output devices.

Just a thought.

N.

[RMW5]

scep said:


RMW5 said:


The price tag is all the PR this board needs.


A "$25 PC" sounds interesting. A "$25, credit card-sized PC" sounds like a must-have.


A "$25, credit card-sized PC" sounds like the monitor, keyboard, mouse and storage have been left out of the equation, so they must cost extra

[BlueClogger]

What's wrong with Blu-Tack?  I've got a smallish ABS box which I can melt holes in with a soldering iron for the ports and hold the board down with the aformentioned.  It has zero conductance, is heat stable within the range of the Pi, easy to remove and is dirt cheap.

[RMW5]

liz said:

It's also the case that silicon is expensive stuff. If we keep the area down, we save money. And that's of paramount importance here. Small is a big win for us because as well as being cute and surprising, it's also cheap.
But as a matter of interest Liz, what is the marginal cost of having say an 85mm x 85 mm board? If it costs an extra £1 then it is worth it because it can save the cost of some sort of contraption to hold the board at its edges.  With VESA mount compatible holes I can fix the PCB to the back of my monitor with 4 nylon bolts + washers at a grand cost of 80p.

[liz]

Couldn't tell you off the top of my head. But you should be aware that when we were wrestling the cost down we were making decisions on componentry, drilling, and routing in the penny arena - every little counts, and there's so much going on on that board that it adds up very quickly (especially once you start factoring in licences and so on).

It's also important to be able to say "size of a credit card" to people; they instantly understand what that means. (It's why so many newspapers use things like football pitches, double decker buses and Nelson's Column as measurements.) It's been a much more effective tool than saying "it measures 85.60mm by 53.98mm" in getting the word out and getting people to understand what we're selling.