I think it is time for a service.
some of the aluminum pulleys for the CoreXY is completely worn out, as is the belt. It fits good that I ran out of filament so I have time to turn new pulleys
edit
I calculated how much filament I’ve bought since I made the pulleys and have printed about 34kg filament with these pulleys .Belts is of course changed several times.
What´s your CoreXY setup? “Twisted” belts?
Wondering since i’m building one myself and i was hoping that if everything was well lined up I wouldn’t get wear like that. Than again, 34Kg is a lot of printing.
Have run with twisted belts past two months and have never had so worn belts before .I noted no improvement in print quality.
This usually happens with cantilevered pulleys which are able to flex with overtightened belts. Or if the pin of the pulleys is not perfectly perpendicular to the mounting plates ie inclined pulleys.
I dont think these have been flexing. They are screwed into solid 8mm aluminum with an M8 bolt and spacer under the bearing
You have to be doing something seriously, seriously wrong for this level of wear to happen on the pulleys, even in aluminum. It’s also way more wear on a timing belt than you should see in a few thousand hours of use. (I’m calculating ~2000 hours for 34kg filament.)
I think the flange angle and belt twisting are giving you problems with belt wear and flange wear. As the yarn is exposed due to belt damage it must be abrading the pulley flange edge where rubbing occurs. A steeper flange angle and a non-twisted belt path would help. I’m also wondering why there is so much evidence of sliding contact on the main pulley face. Is it possible the pulley bearings were locking up at some point?
What’s the width of the pulley face versus the belt width?
@Ryan_Carlyle Have not seen wear on the belts until I tried with twisted belts but the pulleys must have been worn long. All a bearing is absolutely fine and I’d seen if a bearing locked up. Made the face 9mm wide.
@Jan_erik_Halvorsen The neoprene teeth and face of the belt won’t wear aluminum. There are millions and millions of aluminum timing belt pulleys in the world with no meaningful wear after many 10,000s of hours. You should have zero pulley wear with undamaged belts and non-binding pulleys. Maybe some mild burnishing of the flange face at the most.
However, exposed fiberglass yarn due to belt damage would wear aluminum quickly if there was any kind of sliding or relative speed difference, or if the belts were trying to climb up the flanges.
@Ryan_Carlyle Then it must have happened after I switched to twisted belts the belts became so worn that they started digging into the pulleys. The printer have been going 24/7 the last weeks.
I guess we’ll never know if there was any wear before. Really interesting though, thanks for posting the pics.
@Jan_erik_Halvorsen did you make these ?
If so, could it be that the aluminium you used is not hard enough?
@Rien_Stouten I made the pulleys of a 30mm bolt 6082-T6 aluminum.I think it should be hard enough.
Threads are not axles, as much as we all use them that way. The threads get crushed and if the alignment isn’t perfect they then start to promote off axis loading and increasing dip angle, if there is a spacer inbetween the bearings it can then start to jam up against tilting bearings as the threads under it are not loaded. Clamped smooth axles with alignment adjustment shimming for the mount would be better, redoing my i3 like that with 5mm SS pegs, I think they are used for shelving supports in Ikea like shelf units, that are perfect little 1.5"x5mm smooth axles. Machinists square and calipers says they are straight and smooth.
i have twisted belts on my corexy running on flanged bearings. only one of the belts got chewed up on the edge that too because of a misaligned spacer… the other one is as good as new. the printer has chewed through 10+ kg of filament in the last 4 months.
