Step 1: 3D Modeling

So, I start this project with firstly making a 3d model in solidworks. Most of the time welding joints are at 90° angle , so I created a triangle with two perpendicular sides on which I extruded 4 holes for neodymium magnets.

I also extruded out the centre of a triangle to kinda save up on the plastic and that is basically it.

After that I slice it in the simplify 3D with a 15% infill, so lets hop to the CR-10 and print it out.

Step 2: Assembly

It came out perfectly, I mean this Cr-10 is really doing a great job. Furthermore, we are gonna need these neodymium magnets, Link to magnets

So I just take one by one and applyed a decent force to squezze them into one of the four holes.

It is very practical to use some long pliers to secure them in place but be careful not to crack a PLA with too much force. The tolerance here is intentionally pretty snug, to keep all magnets in their position at all times.

I also made a few different size holders for different applications and welding angles.

Step 3: Testing

So to test it out, I use some leftover steel, clamp down the magnet holder and that is it.

Some of you may wonder that is not a good idea, since the PLA plastic will melt due to the heat generated when welding which is true but the point of this is to hold our work piece so we can tack a few small welds in the corners and then we can remove them and weld the remaining section without worrying to melt down the plastic.

Thank you for reading this instructable, if you have any questions, please leave them in the description below and also don't forget to check out a video tutorial at the end. Thanks :)