These are the 3d-printed parts for my Battery Tab Spot Welder Project (see https://www.youtube.com/watch?v=5kWRZHLDFLo )

This is my own take on the many DIY Battery Spot welder projects out there. Most of them are done using an off-the-shelf timer, or an Arduino, but as I had the parts lying around on my desk, this one uses a NodeMCU microcontroller. This project re-uses a 700W microwave oven transformer with the high voltage removed and replaced with a 2V, 350A secondary instead. The main voltage is controlled on it's way into the microwave oven transformer using a cheap Solid-State-Relay module.

The main box, print in PLA without any support, but with a 5mm brim for bed adhesion.
The lid, print in PLA vertically without any supports.
The front panel, print in PLA lying flat on the bed. Support material needed to fill the spaces behind the OLED display and the rotary encoder. Should be pretty easy to clean up afterwards.
Print 3x Aluminium Extrusion Clip in PLA, vertical printing, no support.
Print 2x cable grommets in Ninjaflex
Print 1x Hand rest in Ninjaflex
Print 1x Rotary Encoder Knob in Ninjaflex
Print 4x Feet in Ninjafles

PLA and Ninjaflex required. Cable grommets, Rotary Encoder Knob, Feet and Hand Rest all printed in Ninjaflex - The rest in PLA

With the exception of the front panel, everything else prints without any support material (supports are built into the designs where needed)

This project is released under the Creative Commons Attribution Share Alike License.

Messing around with mains electricity is dangerous business and there are risks of death by electrocution and fire. This series of videos is intended to show you what I did - not to be a defacto guide on the best way to do things. If you decide to undertake your own similar project, I accept no responsibility or liability for anything bad that happens to you.
Do not even think about replicating this project unless you are fully competent in all areas covered and fully understand exactly what you're doing and the risks involved.
There is also an element of danger in welding to batteries, so once again, if you decide to do that, you're doing it entirely at your own risk. If you melt holes in your batteries and they burst into flames, then it's not my fault.

With all of the caveats above, I'd love to see someone else make one the same, or even better make an improved version and contribute back code tweaks or 3D design improvements.
For changes to the code, please raise a pull-request on github.
To collaborate on the 3D-model, you'll need to message me with a Fusion 360 username so that I can give you edit permissions.

Here's the relevant links:

The LUA Code: https://github.com/jimconner/NodeMCU-Dual-Pulse-Weld-Timer
The Autodesk Fusion 360 model: http://a360.co/2sEro9Y