Hello, I have a reprap purse i3 3d printer. Recently I went print a small block, it was supposed to be a square, but every few layer, the printer makes a clicking noise, the finished print is nothing square, along the Y-axle, it keeps shifting every few layers. I think the Y-axle belt is gonna. I need to replace the belt.
When I order the belt, Is the gt2 6mm belt with 2mm pitch the correct one to purchase? and when I replace it, what is the typical length to form the y axle loop? Thanks.

Edited 2 time(s). Last edit at 12/27/2017 11:38AM by rich1812.

Thats what my Prusa I3 Has.

What's pointing you towards a belt needing replacement? It's probably more likely you need to tension your belt or adjust acceleration or jerk.

Its hard to destroy a belt, If it is you'd know. You would be able to see the fibres inside and the rubber would be crumbling away. Your description seems to be pointing to idlers, motors, pulleys or tensioners. Check these points first just to be sure.

Other then that GT2 6mm belt is the most common. How much you need is dependant on the printer, but I'd recommend ordering more then you think as its so cheap

Thank you all for replying.

Actually I am not sure if it is the belt need to be replaced. I an never tell how much tension need to apply to it. As Origamib said I do not see any damages on the belt visually. How to properly check the idlers, motors, pulleys or tensioners?

The belt should not be real tight. but tight enough that so if you push the bed back for forth quickly you don't hear the belt jumping teeth.

Some use an old cloth pin spring to tighten the belt. I tried but could not get the spring to stay on the belt. My belt is snug not tight. and has worked for over a year.

Do you know why we use glass or steel core belts? Because they don't stretch (much). Do you know what happens when you put one of those spring tensioners on a belt? You turn the belt into a spring that stretches. Don't use those things. If the belt isn't tight enough, adjust it at the clamp.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

On the other hand, to replace the weak springs of the crappy cloth pins available today by these belt springs will give a firmer grip allowing your clothes to dry fast in the most furious wind !

To try to have the belt jump the motor pulley is not the right way. It is amusing to perform though Yes, the belt must be tight, it is all described in the Gates and other mfg documents. The right tension is easy to get provided a proper adjustment mechanism exists.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Does your printer not have tensioners, sound like its loose.
if not, have you tried taking the belt off, pulling it tighter and refixing to the clamps?
Any 6mm GT2 belt will work as long as it is long enough.
As others have said, always buy longer then you need.

BTW a bicycle puncture repair kit has everything you need to fix belts of turn them into closed loop belts.

Edited 2 time(s). Last edit at 12/29/2017 04:35AM by GRAYWOLF.

So basically check everything along the belts path. Your pulleys and idlers should be straight and moving freely. If they are not straight you will see the belt move backwards and forwards slightly as it rides up and down the pulley.

Check the motor and pulley, you may find the grubb screw has come loose.

Check your belt tensioner, or the place where the belt secures to the carriage it may have slipped.

Check your motor wiring. Broken wires may cause intermittent connection.

The OP mentioned a clicking, this could also point to a stepper losing steps. Are the layer shifts big, like a couple of mm? Or just small ridges?
Since this is the y axis of an i3, I'm inclined to think you need to turn down jerk and acceleration. Just thinking about it now, a belt skipping teeth isn't exactly what I'd call a click, but a stepper skipping steps is.

Just another thing worth checking.

Quote
Trakyan
The OP mentioned a clicking, this could also point to a stepper losing steps. Are the layer shifts big, like a couple of mm? Or just small ridges?
Since this is the y axis of an i3, I'm inclined to think you need to turn down jerk and acceleration. Just thinking about it now, a belt skipping teeth isn't exactly what I'd call a click, but a stepper skipping steps is.

Just another thing worth checking.

I agree, in fact when my motor wires came slightly free it caused the extruder to lose torque and click

Happy new year! Thank you everyone foe the replay. I am wondering if the Y acceleration in the firmware can contribute to this factor? (I use Marlin.) Also I noticed the the wheel, end, not the motor end, keeps wriggling back and forth when the printing the in fill, could this be a factor as well?