Joining Left over Rolls of Filament


Just wondering if anyone has a good solution for joining the left over on each spoil? 

Most of my prints are long 12 hours plus, so I run the print over night when I'm not at work.

The main materials I use are ABS and HIPS. 

Any ideas? 

I've tried joining with a flame, ultrasonic knife and acetone but all seem brittle if they join.

Thanks Mike

Drill a hole in filament A, carve a corresponding peg in filament B, pipe a tiny amount of acetone into the hole, attach, and let it set overnight?

I have a similar issue with multiple M200s so I have a bunch of rolls with small amounts of filament. I typically save them for when I can spend an 8 hour day running small parts and I just monitor them closely to swap small rolls. I'd love to see larger rolls of filament available so I swap rolls less often. Apparently there aren't many Zortrax "production" customers or there would be more people asking for this and other time saving "production" features ("Print Again" menu option). All with due time.......

Spool size is limited by how much weight the extruder stepper can pull. Too much and the extruder gear will strip your filament.

I was successfully feeding the M200 with  2KG spools on a spool holder with ball bearings from below the printer.

I cannot see why not even bigger spools could be used.

Mine couldn’t pull a spool of Copperfill. Wasn’t using bearings though.

Bearings make the difference with such big spools, but Copperfil is known to give trouble with some hotends too.

Namely Teflon isolations inside the hotend (wich would be true for a V2 M200) could cause adhesion according to the manufacturer.

This would cause additional friction if not cllicking at all and a worn M200 filament tube could add adhesion also.

I still have the Colorfabb filaments in their boxes, don't have time to troubleshoot that filaments on the 200.