Simple Filament Welder

Just a simple tool to hold a PTFE tube to weld filament. You need to mount them on a plate (I used an old piece of furniture board for that). Next you need two PC4M6 PTFE couplers and two spool holders. Plenty to find here on Thingiverse. Because I don't use the original Creality Metal Spoolholders, I used those.

I printed it in PETG, but PLA is just as good.

One block and the slider mount are fastened to the furniture board. The other block just slides into the slider. It has no locking, the PTFE tube just holds the block in place.

Put the filament in the tube left and right. Heat up the tube with an soldering iron (not using the tip, but the shaft) and heat it up. Move filament from left to right and let it properly cool down. Then just wind the old spool to the new one. Maybe clean up the welding point a little if it looks bulgy.