Compact case for Heltec v4 GPS Meshtastic node

Description

Compact printed case for Heltec V4 Meshtastic client with GPS.
External dimensions are 74x44x21.7mm.

This case meant to be used with this default Heltec V4 GPS set:

Required BOM

1. 803048 Li-Po battery (consider buying with preinstalled JST-SH-1.25 Connector);
2. 4x M2 heated inserts;
3. 4x M2x16 hex cap head screws;
4. Thin double-sided tape;
5. Kapton tape if you use battery without preinstalled connector.

Printing

This case could be printed in multiple materials given low expected mechanical loads.

I've used some basic PLA with rather rough parameters for drafts - 0.24mm layer, 2 perimeters, 10% infill, and found that it would suffice for a functional part.
But for aesthetic purposes you could use something like 0.16mm layer, 3-4 perimeters, 30% infill, scarf seam.

Models should be oriented as on following image:

Consider placing button onto it's bottom if you getting squished front layer, but surface finish would be nicer if you print on top surface. You may also need to slightly adjust button scale on XY plane depending on your printer tolerances.

Assembly

Preparing battery

LIABILITY DISCLAIMER
This step is dangerous, consider buying battery with preinstalled connector to avoid it altogether. 
If you are not familial with soldering small parts & working with LiPo batteries, you will literally set your workplace on fire that could not be easily put off with any conventional means.
Keep in mind that you proceeding on your own risk. 

Prepare appropriate container to withstand burning LiPo battery if you mess it up. Prepare some fire extinguisher or other means to put out fire from other things that may be lit with battery.
Do not short battery leads, pinch, pierce or drop the battery at any time. Do not use conductive tweezers or other tools that could short the battery.

1. Strip the battery from factory kapton tape insulation & straighten battery leads with BMS PCB. Carefully de-solder original wires from PCB one at a time without shorting any leads.
   You should end up with battery looking like this:
   
2. Cut one of Heltec-provided JST-SH-1.25 wires to required length. You need about 95mm for positive wire & 100mm for negative wire:
   
3. Solder the wires to BMC outputs (it may be useful to double-check polarity):
   
4. Thread the wires below the PCB. Bend the wires to the positive terminal side. Isolate them from lead with small wrap of kapton tape:
   
5. Isolate PCB & leads with wide Kapton strip from one side of battery case to another:
   
   
6. Bend battery leads with PCB onto it's original position:
   
   
7. Reinforce insulation with thin roll of kapton across previous kapton layer & then along the battery edges:
   

At this point the battery part is done.

Assembling the case

1. Install 4x M2 heated inserts to CaseBottom part;
2. Put UsrButton to the corresponding CaseTop slot. Button should be moving freely, if not - try tuning tolerances or cutting some surface defects;
3. Assemble all Heltec components & battery as on following image:
   
4. Place the wire along path shown on the following image:
   
   That's needed to be able to install BatteryPlate part;
5. Put the BatteryPlate part on corresponding notch, it shouldn't pinch battery wire:
   
6. Add a piece of thin double-sided tape onto battery:
   
7. Place the battery with adhesive facing upwards in the battery pocket of CaseBottom part, then peel off protective layer from double-sided tape:
   
8. Hold BatteryPlate with some thin object (e.g. thin ruler, ceramic tweezers), put CaseTop with BatteryPlate above the CaseBottom, then slide GPS module into corresponding pocket in CaseBottom to use GPS module as a guide. Put CaseTop & CaseBottom as close as you can, and let go of the BatteryPlate. Put CaseTop & CaseBottom together by hand on one another:
   
9. Reopen the parts and verify that battery position is appropriate for easy assembly. If that's ok - gently apply some pressure on battery & BatteryPlate to let them fully adhere, if otherwise - remove BatteryPlate from battery & repeat previous step:
   
10. Assemble CaseTop with BatteryPlate & battery:
    
11. Put CaseBottom onto previous assembly, and fix everything together with 4x M2 screws:
    

At this point the assembly part is done, you may proceed to flashing Heltec V4 with Meshtastic according to official docs.

FAQ

How to press RST or look for LED status

There is a hole on the front panel that allows you to access RST with paper clip. LED is visible through the same hole.

How to turn it off when there is no power switch & no way to disconnect the battery

That's implemented in Meshtastic firmware on the System screen:

Also, you can turn GPS on & off the same way on the Position screen.

Buy pre-printed case

If you live in Russia, you can order this case from me pre-printed and with installed heat inserts via Avito:
Корпус ноды Meshtasic на базе модуля Heltec V4 GPS