Low Profile Solar Meshtastic Car Node

Update 22 Sept 24: T114 tray variant now published.  There's 2 files, the tray and the strap.  Secures with M3x8 screws and also helps orient the GPS in the correct position.

Update 21 Sept 24: Enlarged internal hole size for N-type shell pigtails.  Should now fit the larger 22mm diameter base found on some versions.  Added as an additional option for those who need it, listed as V2.2 in the files.

Update 5 Sept 24:  Changed TPU gasket file, new version overlaps edges to provide more structural support to help keep it in place during assembly.  I use a couple drops of superglue to hold mine in place, but shouldn't be needed with this version.

UPDATE 3 Sept 24:  Added N-Type shell variant.  Recommended pigtail here: https://a.co/d/cnaridz and recommended antenna here: https://store.rokland.com/products/alfa-aoa-915-5acm-5-dbi-omni-outdoor-915mhz-802-11ah-mini-antenna-for-lora-halow-application

This is published under non-commercial license.  You are free to print this for yourself, but not to be printed and sold.  I will not be allowing remixes of this design, but can incorporate improvements or special use cases on request.  Now, the good parts:

I wanted a solar powered roof mounted node for Meshtastic, without the drag and bulk.  This is the result of a few iterations and testing.  This is designed as a shell, gasket, and swappable tray for the the electronics, and spacers to hold the back of the panel at correct height.  Battery is of your choice, whatever you want to fit in there.  Works with RAK 19003, 19007, and soon will add Heltec T114 version.  This is a tricky print that requires good supports, so use your best judgement on orientation, materials, support types, etc.  Recommended magnets are rubber coated and very powerful to make sure it stays put.  Has been road tested at highway speeds, in the rain, and I'm very happy with the results so far.

Paint warning:  If you like your car's paint, I highly recommend putting down a layer of paint protection film on your car before mounting the node.  I am not responsible for damage caused to your car or anybody else's.

Weather resistance:  This was designed to live in the elements and weather, however I make no guarantees this will keep out all water or handle the climate where you live.  DO NOT PRINT THIS IN PLA, it will warp in heat and sun.  I am not responsible for damaged electronics, at the end of the day this is an enclosure file for your own DIY build.  Use your best judgement.

Parts needed: 

Print 1x of the shell, 1x of the tray for your radio, 1x TPU gasket, and 2x spacers.  Recommend ASA, but may work in PETG.  I have one printed in PETG and will be testing long term to see how it holds up.

Was designed around these magnets and screws: https://a.co/d/5zJAw4R

Here is the panel used: https://a.co/d/1cngMUD

Requires the SMA pigtail and antenna of your choice.  Recommend sealing with silicone or your preferred method to minimize corrosion and reduce chances of water making its way through the enclosure at the SMA.

Hardware to mount the tray to the shell will be M3x8 stainless screws, M3x6 should work too.  I tried to design so the hardware will be recessed, but make sure there's no metal sticking out that can scratch or damage your car after assembly.  Screws should self thread into the printed parts.  Heat set inserts are not recommended due to possibility of corrosion.  RAK boards mount with their included M2.5 hardware.

When putting the magnets on, recommend to use some blue thread locker on the screws and not overtighten.  I may design some 3d printed washers or inserts for this if needed, seemed to work as-is with no washers for me.  The 2x spacers are for the back side of the panel so it is properly spaced to clear the box underneath the panel.  There is also a barrel connector included underneath the panel, this can be clipped off and sealed up to prevent shorts and corrosion.  I use a short section of heat shrink tubing and let some hang off the end of the wire.  After heating, squeeze the open end together for a good weatherproof seal.

For wiring, run the solar power wire into the tray, cut to length and solder in the RAK solar connector.  Add battery and secure with double-sided tape.  Mount GPS if desired.

If you have recommended improvements or run into issues, I'll do my best to address them.

Find out more about the Meshtastic project at https://meshtastic.org

This will also be posted in the Meshtastic discord at https://discord.com/channels/867578229534359593/1280301735193350234 if you have any questions or want to share ideas for improvements.