fakeTec 18650 case

Why

This case has been created for this workshop: https://hacklabbo.indivia.net/hackordiye25/programma/#workshop-assembla-il-tuo-nodo-lora (hence the “HoD 2025” on on of the three lids) where we'll provide 20kits to create an fakeTec portable node to spread our network and contaminate interested people.

NB: the photos of the printed node is an older revision (v26) of the actual files which are and improved one (v30)

General info

the case contains:

• faketec v3 pcb + NRF52 + lora module
• small antenna
• 18650 holder
• battery switch

TODO for the next revision:

• test if a BMS for the battery fits in the battery compartment or above
• add JST connectors to remove the battery
• export single components so they can be viewed in the 3d viewer on this site

Printing

the print has been engineered so you'll need no support, you can print it like this:

I am using eSUN PLA+ with these print settings:

• Bambu A1 Mini
• profile: 0.20mm strength
• Strength: walls: 4
• other settings: default for eSUN PLA+
• textured PEI plate
• printing speed both 50% and 100% do not send the case flying (which is top heavy)

with these settings the total filament needed is 34g =~ 0.50eur per case +  power consumption

the result with a well dried filament is good, in the photos you see the bone colored filament which was not very dry so it had some issues.

I am using PLA+ because it's easy as PLA to print but has many proprieties like PETG, like heat resistance and at some point this thing will generate heat recharging the battery.

BOM

or “bill of materials”

this tutorial takes for granted that you know how to build and already have a basic fakeTec node (v3 preferred) (https://github.com/gargomoma/fakeTec_pcb), the only thing you'll need to do is to assemble the NRF on the PCB using the connectors provided with the NRF so the usb port alignes:

to assemble the case you'll need:

• 3x M2 hot inserts (and the tool to install them)
  • https://it.aliexpress.com/item/4000232858343.html
  • M2 X D4.0 X L4.0 (or M2 X D4.0 X L3.0 should do fine but untested)
• 3x M2 screws, at least M2x6mm but also 10mm long will fit
  • https://it.aliexpress.com/item/1005009217210712.html
  • 25pcs M2, length 6mm to 10mm
  • choose a hex head without knurling
• Switch
  • https://it.aliexpress.com/item/1005008904067609.html
  • type: k014a004-G3
• Antenna
  • https://it.aliexpress.com/item/1005006099597672.html
• Spare cables for the battery/switch
• Battery holder
  • https://it.aliexpress.com/item/1005005084346241.html
• Battery BMS if you use unprotected cells:
  • https://it.aliexpress.com/item/1005006724813699.html
• 18650 lipo battery
• JST 1.25 male and female connector
  • are rated for 1A so for our charge at 500mAh should do just fine
  • https://it.aliexpress.com/item/1005006623051278.html
• Tools:
  • xacto knife to trim the parts
  • Cyanoacrylate glue (like Super Attack in italian, or generic Cianoacrilato)
    • be very careful with this kind of glue since it glues skin and eyes very well
  • Soldering iron with good thin tip, not too thin but thin enough.

I'll also link the parts we ordered for our faketec nodes:

• NRF52 nice nano compatbile
  • https://it.aliexpress.com/item/1005006446457448.html
• Button
  • https://it.aliexpress.com/item/4001317902663.html
  • type: 3X4X2mm 2Pin
• HT-Ra62 lora module
  • https://it.aliexpress.com/item/1005008549605642.html
• Smd resistor for the battery level
  • https://it.aliexpress.com/item/1005002991902748.html
  • type: 100pcs 1M ohm100pcs 1M ohm

INSTRUCTIONS

• never power on the node without an antenna attached! you might fry the radio
• the holes marked with “hi” and an arrow are not greeting you, it signals the holes where to place an hot insert!

1: take all the printed parts and insert and remove the “shelf” from the case so the parts that grind together gest a little smoother

2: try to fit the parts that need gluing: the shelf in the lid groove, the antenna support in it's groove on the shelf and the screw knob on the screw adjust were needed
the parts should slide in their grooves but remain planted if possible

3: glue the parts: apply the glue in the groove and then press the other part in, be quick to set the part at the right angle

4: take the case and the switch holder, insert the hot inserts in the holes marked “hi”

5: place the switch in it's place, place the switch holder behind it and screw it in place

6: place the fakeTec in it's holder, then insert the antenna's connector in the antenna holder (you might need to force it a bit to make it slide) and connect it to the lora module

7: take the battery holder and file down any burrs on the sides that might prevent correct sliding in the battery holder, then try to slide it in and out

8: before continuing soldering the cables try to figure out the best routing and length of the cables,
the JST connector installation is still untested since I am waiting for them but I'll update the guide once I have one 

9: set the battery in it's holder, if the cell is unprotected (usually if the top (+) is flat the cell is unprotected), add the BMS to the battery (TBD)

10: end the battery cable with a JST 1.25 connector (female, the one with the contacts protected so we don't risk any short on the battery)

11: take a JST 1.25 male connector and solder the positive to the upper switch contact (the cabling on the image is wrong, the red notes are correct)
don't use the bottom contact otherwise the switch won't follow the case “ON and OFF” markings

the negative contact of the male JST should go directly to the BAT- or B- on the board
now take a spare cable and solder to the mid switch contact to the BAT+ or B+ on the board

12: with everything soldered you can carefully slide the battery in it's hole and the shelf in it's place, when you are halfway trough you can con plug the JST connectors and continue closing the case

13: screw on the closing screw, the one with the knob

14: power on

15: ?

16: profit!

Copyright and licensing

Regarding the Meshtastic logo used in the Lid_Meshtastic:
"This model is not affiliated with or endorsed by the Meshtastic project"
https://meshtastic.org/docs/legal/licensing-and-trademark/https://meshtastic.org/docs/legal/licensing-and-trademark/