Custom enclosure

[brinzlee]

I know this is for the Raspberry Pi Zero....but I love how simple this guy makes it look to 3D print a case

Perhaps we should ask him to design us one

https://www.youtube.com/watch?v=rnS80vaDuq0

[rg]

The unit I modeled is coming out at around £30-40 to have 3D printed and even more to have printed in ABS. While this might be OK for a one off prototype I think its way too expensive.

A bespoke snap fit enclosure like this  (X=60.00 Y=140.00 Z=25.00)  would cost a one off fee of £195 for design to have stand offs and cut-outs inserted then unit costs of less than £12 (based on 25 units) and as low as £7.


Alright if enough people want to enclosure to protect the dongles hanging out of the pi.

[Richard]

Rg.
  I agree too expensive. But Good idea. Your second option looks more promising. Can you dicribe the standoff a little more please. Will the standoff fit the holes in the Pi board and allow the enclosure to be screwed together? You mention cutout? Is this for the power supply use plug?

[DaveStyles]

Hi rg,

email sent ! This looks like something that PilotAware Hardware could help with, we have a 3D printer the project can use for prototyping. We also have some contacts to have bespoke cases injection moulded at reasonable cost. (cheaper than above)

I've dropped you a line by email, everyone has been working flat out on getting the technical parts working, maybe we could look at bespoke cases now, in the spirit of PilotAware, we could do it collaboratively and come up with the perfect case !

regards

Dave Styles
PilotAware Hardware.

[rg]

Rg.
  I agree too expensive. But Good idea. Your second option looks more promising. Can you dicribe the standoff a little more please. Will the standoff fit the holes in the Pi board and allow the enclosure to be screwed together? You mention cutout? Is this for the power supply use plug?

Standoffs would allow the pi board to be screwed down.  The enclosure snap fits together without screws.

Cut outs would be to allow pi ports to be access etc.

[Richard]

That sounds great. Put me down for two please.

[rollingcircle]

The unit I modeled is coming out at around £30-40 to have 3D printed and even more to have printed in ABS.

That does seem way over the top.  The case I've put together weighs in at 75g, and at the price I'm paying for PLA and ABS (£18 a kilo - cheaper filaments are available) it that comes in at £1.35 a pop, plus whatever electricity the printer uses in the process.  Obviously, I've probably printed off a kilo or so in prototyping, but once you've got a workable design the cost of the 3D printed item is nowhere near £30-£40.

For those that are interested, I've put the OpenSCAD source files and STLs for the case here:

https://github.com/rollingcircle/packapaw

Basically, the idea was to swap out one of the USB ports in the Pi with a header, remove the cases from the DVB and GPS dongles, and mount them inside the case wired directly to the headers.

The base is pretty much a generic B+ design, with the second USB port blocked off...

https://github.com/rollingcircle/packapaw/blob/master/packapaw_base.stl

..the lid has voids for the antennas, and mounting brackets for the two modules...

https://github.com/rollingcircle/packapaw/blob/master/packapaw_top.stl

The DVB dongle mount clamps at either end, leaving the board in free air for cooling - I haven't really had time for much testing, but running it on the bench for an hour or so the lid over the dongle only became faintly warm.











I did notice the GPS was rather less sensitive in there with the ARF powered up, but being next to the ARF is probably a GPS module's equivalent of sticking your head in a speaker stack at a Motorhead concert.

The OpenSCAD source and the STLs are up on GitHub under the Creative Commons license, so you can do what you want with them.

The case needs a bit more work - the tapered capture in the bolt holes is a bit abrupt, so currently difficult to screw the halves together tightly.

So, if you needed another reason to get yourself a 3D printer for Christmas, there you go!

[rg]

It's a much bigger volume and the commercial firms offering the higher quality materials seems to be going on overall size of part rather than just volume of material used.   

I'm more interested in your usb port mod.  What skill level is required to pull that off?

[rollingcircle]

It's a much bigger volume and the commercial firms offering the higher quality materials seems to be going on overall size of part rather than just volume of material used.   

I'm more interested in your usb port mod.  What skill level is required to pull that off?

Not sure why they would be quoting on sheer volume, unless your design required support material?  A design with large unsupported features would require a multi-head printer and expensive soluble support materials, which would push the price up.

No particular skills required to de-solder the USB socket - a decent vacuum desoldering station helps, but ultimately you could do it with some solder-wick and a basic soldering iron.  Those manual solder-sucker pumps are next to useless though.

The header pins are standard 2.54mm headers, but the spacing of the holes for the USB socket aren't exactly 2.54mm, so arranging them as 2x4 vs 4x2, and a bit of fine trimming of the plastic shroud is required.  The cables use single vertical A-type USB PCB header to connect to the dongles.

[JCurtis]

It's a much bigger volume and the commercial firms offering the higher quality materials seems to be going on overall size of part rather than just volume of material used.   

I'm more interested in your usb port mod.  What skill level is required to pull that off?

Not sure why they would be quoting on sheer volume, unless your design required support material?  A design with large unsupported features would require a multi-head printer and expensive soluble support materials, which would push the price up.

No particular skills required to de-solder the USB socket - a decent vacuum desoldering station helps, but ultimately you could do it with some solder-wick and a basic soldering iron.  Those manual solder-sucker pumps are next to useless though.

The header pins are standard 2.54mm headers, but the spacing of the holes for the USB socket aren't exactly 2.54mm, so arranging them as 2x4 vs 4x2, and a bit of fine trimming of the plastic shroud is required.  The cables use single vertical A-type USB PCB header to connect to the dongles.

Just be careful about this mod and the potential affect on signal integrity.  USB requires a twisted pair for the data wires, and it should also be shielded to prevent both ingress and egress of noise.  There is a potential to quite easily cause corruption of the data on the USB.  At the very least please twist the D-/D+ wires together.

The pinouts for this type of connector are a standard, the attached file is the layout for the Molex connectors I use in my chargers, FYI.

[Richard]

I would stay with a longer enclosure an leave the Pi as it is. We are trying to make the PAW hardware user friendly, as most users will not want to start taking it to bits. Keep it simple and it will all be good. It all needs to fit together in one box, put the lid on and go fly.

[rollingcircle]

It's a much bigger volume and the commercial firms offering the higher quality materials seems to be going on overall size of part rather than just volume of material used.   

I'm more interested in your usb port mod.  What skill level is required to pull that off?

Not sure why they would be quoting on sheer volume, unless your design required support material?  A design with large unsupported features would require a multi-head printer and expensive soluble support materials, which would push the price up.

No particular skills required to de-solder the USB socket - a decent vacuum desoldering station helps, but ultimately you could do it with some solder-wick and a basic soldering iron.  Those manual solder-sucker pumps are next to useless though.

The header pins are standard 2.54mm headers, but the spacing of the holes for the USB socket aren't exactly 2.54mm, so arranging them as 2x4 vs 4x2, and a bit of fine trimming of the plastic shroud is required.  The cables use single vertical A-type USB PCB header to connect to the dongles.

Just be careful about this mod and the potential affect on signal integrity.  USB requires a twisted pair for the data wires, and it should also be shielded to prevent both ingress and egress of noise.  There is a potential to quite easily cause corruption of the data on the USB.  At the very least please twist the D-/D+ wires together.

The pinouts for this type of connector are a standard, the attached file is the layout for the Molex connectors I use in my chargers, FYI.

No USB data corruption observed as yet, but you're right - was planning on swapping those cable out with shielded items. 

[rg]

Well I finally got the concept printed.  First time having an object printed for me as I usually get things sintered so a little disappointed with finish and the object isn't quite precise enough to be used (screw holes not right size and cable ports deformed). The design works well enough but needs a higher resolution printer.



I think it might be more useful to look at a printed part that can be inserted into an extruded aluminium off-the-shelf case

[Richard]

Looks Good. Just needs tweeking...

[rg]

A slight evolution of the design....

The pi sits on standoffs with small lugs on the to locate the pi board. longer standoffs from the lid trap the pi onto them and the lids is screwed to the base from the below using countersunk m2.5 machine screws.

A couple more small tweaks to make to improve the installation of the pi and allow a usb gps on extension cable out through the case and I'll post the STL files.





There is a disadvantage in having to open the case to access the ethernet or usb ports for software updates (though the sd card can be accessed externally) but for me this outweighs the advantage of having a single robust unit that I can take in and out of different aircraft.

I don't use the GPS dongle but case is large enough for one.  Instead opted to use collisionaware/nmeagps route and so this case stays in my bag. usually behind the p2 seat with the 1090 antenna sticking up vertically and the tuned low profile antenna gets stuck to the rear windows with slot head suction cups acquired here http://www.suctioncupsdirect.co.uk/ .  The only cable to sneak between the seats in the audio lead to plug into my headset.