My printrbot simple metal was having some issues printing straight lines (see picture). I increased the number of shells but the problem remains. So I decided to re-tension the belt. I look at the belt clip and it is deformed. There is some slack in the belt. Not a lot but when I feel it with my fingers, the belt is not as taut as before.
After re-tension the belt, the print comes up much improved. It seems GT2 rubber belts lose tension slowly. What do you guys suggest we do to compensate for this? Try a different belt kind? Something that is GT2 profile is even better. Or is this just something that is part of the 3d printer list of consumables?
I’ve owned a PrintrBot Jr for a year and a month that’s using GT2 rubber belts. I have to re tighten the belts every few months if I want truly excellent prints. Until a metal chain driven system is made, which I’m not sure I would like, this is just something you have to do once in a while. I’ve started routinely checking belt tension and greasing the linear bearings every 3 months. Its probably a bit excessive but it works.
Your acceleration and jerk might be too much for the machine. I would also closely examine the tab that is gripping the belts. I don’t think the belt is stretching that badly, it’s more likely that it is getting loose at the clamp.
Gt2 should remain tight. If not, you may have some faulty belts or something else is coming loose. That ghosting is a result of your hot end oscillating after a severe direction change (note the consistent frequency but decreasing amplitude) it’s usually loose belts or too much flex/deflection in the hot end. An easy way to check is to enable your xy axis steppers and then try to manually move the tip of your hot end about (when it’s cold). If there is any movement you need to locate the cause and eliminate it.
Belts are cheap, so we like them. Stretch happens but I’ve never had to replace them because of stretch. Just check them and tighten from time to time. I find they stretch a teence early on then it slows to nothing once they relax. Tight belts are a must for good prints. I mean guitar string tight.
