Added a v1.0 version of the 50x50x10mm variant, and it's base is the 'official' fan cover released by SunFounder. I'll be updating the other variants (30x30,40x40, etc) to use the same 'base' as soon as I can.
Updated to v0.8 - Minor tweaks to the position of the 'lock' detents along the back.
This is a replacement cover for the RasPad tablet from kickstarter The standard cover is not vented, and even if you run with the cover off, the Raspberry Pi overheats and begins throttling.
This cover replaces the stock cover and 'holder' for the Pi. It has 'nubs' that hold the Pi in place via the USB port and HDMI jack instead of the separate 'holder'. It incorporates a fan holder and has vent slots to allow intake and exhaust air. The slots extend all the way to the back cover where the GPIO opening is, so even if the RasPad is on your lap or a soft surface, it should still cool alright as long as some of the vent is still 'open'.
You should also still be able to use a GPIO cable with this, although you'd have to come up with a way to power the fan other than pins 4 and 6 on the GPIO header...
THIS IS A WORK-IN-PROGRESS - Hence the v0.x notation. This is literally my 8th version of the cover, making small tweaks here and there to get it to fit better. IT'S NOT QUITE PERFECT YET... But does fit really well so far, and clears the Pi 3B+ with the RasPad provided heatsinks.
This cover will need some tweaks before it will work with a Tinkerboard, as it's heatsink is a bit bigger and won't clear the fan currently. I'll work on that once I've settled down on the revisions of the Pi 3 model. ;-)
NOTE I'm currently using a 12v 40x40x10mm fan at 5v as that's all I happened to have on hand. It seems to work well, and in a room that's about 85F/30c, the CPU is staying between 52-59c and is NOT THROTTLING! Perfect! Goal accomplished!
NOTE 2: The pictures are of my 0.5 design, but is very close to the newer variants that have minor fitament tweaks. ;-)
v0.8 released! BETTER FIT OVERALL -- almost perfect! Fits quiet well!!!
I've added variants for a 30mm fan.
I've added a 'NO FAN' plate (vent slots only) so that you can re-mix with your own fan design if you want to...
I've also added a 'BLANK' plate that you can re-mix with your own fan design...
I'll be adding a 60mm version soon (if there's room for it, LOL!)
**50mm variant released, and it's based on the 'official' Sunfounder fan cover.
Upgraded CTC Dual (Makerbot Clone)
TOP/BOTTOM LAYERS: I printed with 3 bottom layers and 4 top layers. I suggest printing with at least 2 of each so that the small horizontal tabs will be 100% fill.
SUPPORTS: I use Simplify 3D and was able to manually place supports under the tabs. If your slicing software does not allow manual placement of support, hopefully it chooses the correct places. (It may not put support under the tabs that only have 2mm clearance...)
See pic for my support placement with S3D.
When cleaning up the part, make sure you get all the support material under the tabs and try to to be gentle as to not break the tabs. The ones on the curved edge are quite small and fragile.
I also used a file to flatten the 3 large tabs a bit after printing to be nice and consistent thickness so that they fit in the slots properly.
Starting with 0.7 I made the tab near the corner a little bit taller than normal so that it can be filed down to be nice and smooth and hopefully 100% fill (if you followed my instructions to use at least 2 top and bottom layers.) File it down to be even with the edge of the cover.
When routing the power lead, make sure it doesn't interfere with the fan. I routed mine along the back of the GPIO header, over towards the USB ports.
Hacked it out in Tinkercad in a couple of days...
It's not perfect, LOL! More revisions will be uploaded as I make them.