I recently purchased one of these Sunlu filament joiners, and have had good success with it. However, it can be a bit fiddly holding everything together when joining two spools, as the natural tension of the wound filament tries to lift it up away from the centre.

I found this model by Stonxx here: https://www.crealitycloud.com/user-profile/8140046369?visitorPage=1 which helps hold everything in place during the welding.

I printed it out but felt it could do with being a bit wider and also tilted towards the user to make it even easier.

So I’ve redesigned the base to be both bigger, and angled forward which makes it a bit more robust. I printed my version in rainbow pla+ (tried ironing on the angled top surface which didn’t go too well, don’t judge!) and am really happy with how it now sits. I also added the correct front curve and a lip to hold the joiner in place, as the original model doesn’t have this and it was rocking around in the holder. I also added a small cutout at the rear to accommodate to power connection as it bulges down and wouldn’t allow the welder to sit dead flat.

I added 4no. cutouts in the base to suit 10mm self adhesive gel dots, to stop it sliding around the table.

I’ve included the original swing arms, lower spindle, and filament guides as these are unchanged.

Please consider giving me a boost if you like it!

My print settings were:

Creality rainbow pla+

220c nozzle. 60c bed

max volumetric speed 14mm3/s

normal snug supports, 0.2mm top z distance, 40deg overhang, build plate only - only for the base

10mm brim for the swing arms and filament guides

Sunlu filament joiner helper

0.2mm layer, 2 walls, 15% infill

K2 Plus, 0.2mm layer, 0.4 nozzle, 2 walls, 15% infill

0.2mm layer, 2 walls, 15% infill