Help with my first 3D Reprap printer

[Slgillan]

Just got a Prusa I3 (He 3D) reprap printer. This is my first ever 3D printer and the learning curve is great. I’ve got to the stage where I’m printing from sample files (spare parts for the printer). I can load and slice the file and send it to the printer.

It starts printing and seems to be going well but for some reason after a short time, I think normally on the second or third layer, the Extruder always moves off the print (maybe by 4-5 cm) and continues trying to print but off the object it was printing. Obviously because the hotend is now off the hotbed the fililment just comes out and goes anywhere.

Does anybody have an idea if this is a problem with the slicing or some setting in Repetier that is causing this problem? Any help would be greatly appreciated, I’m still trying to figure the whole thing out!

thanks

[Noah]

Hello and welcome to the community! I have a prusa myself and I agree the learning curve is steep. My guess is that you’re getting some belt slippage. Make sure you have the x and y belts nice and tight, you can use clothes pin springs or even a 3d printed belt tightened to tighten them up.

[FastProtos.com]

Hi, I don’t have a Prusa but I do have a belt-driven printer and I have fixed and researched many printer problems like this. I would also guess this is a mechanical problem. Belt slippage seems to be quite common. But it could also be a weak stepper motor. If you can check the motor current and verify it’s set correctly (like 1.2 amps for example), then that’s probably not the issue. One final possibility is too much friction on your rails. You might be able to test that by sliding the print head in each direction (with the motors off) looking for tight spots. Move the print head slowly or you could damage the motor drivers. Also, if your prints are only off in only one axis you know which one to investigate.

[Jase_Buckley]

Hello,

I had this in the early days and it was my e-step calibration. Basically on the next layer, the print would jam as too much previously extruded and it would either slip the belt or shift the entire print. 4-5cm sounds extreme however.

I am sure you are at the stage of not being able to take your eyes off the printer while it prints so watching and listening is a good trouble shooting technique. I can hear from another room if the ‘music’ goes strange now.

Good luck,

Jase

[Slgillan]

Thanks guys, it’s appreciated! I’ll double check but I haven’t heard or seen the belt slip. It just seems to finish a layer, move up on the z axis 0.2mm then zips along about +4cm’s on the x axis under control apparently, like it knows what it’s doing and keeps printing without missing a step. Problem then of course is that the hotend is now 0.2-0.4mm off the hotbed and as it continues trying to print then the fililment is just hanging and goes everywhere.

its a weird one… Could it be something to do with the jumpers on the main board. To be honest the instructions were in Chinese and terrible English. It didn’t even mention the jumpers just included them in a wee zip lock back and I just had to zoom in on one of the photos supplied and do my best to pace the jumpers as they looked in the photo.

any comments welcome, as I said I’m complete newbie to 3D printing, loving it but frustrated at the moment…lol

[Jase_Buckley]

Have you opened your stl in http://gcode.ws? A very long shot but just maybe the printer is doing what it is told to do?

You can see each layer in this web app.

I agree with others that it sounds mechanical - belts tight is far better than belts loose and you may not necessarily hear that.

It’s like a car fan belt - they should be tight and only flex a couple of mm’s.

[Miro]

First thing I would do is check vref on stepper drivers(google it)

[kissfan4]

Just be careful using a clothes pin spring, thats what i was using, and it was the cause of my layer shift.

[ProtoPrynt]

This is most likely an issue with your stepper current being incorrectly set (please see the guide that came with your kit, otherwise if you have a melzi board follow these instructions http://reprap.org/wiki/RepRapPro\_Setting\_Motor\_Currents)

If this is set too high your stepper driver will overheat and miss steps, if it’s too low your stepper will not have enough power to move smoothly also causing it to miss steps.

the only other logical explanation without more information is that your axis is binding/ too tight, with the printer turned off you should be able to easily push the axis by hand.

[BeregAlto]

Try to check option in firmware called motor timeout (or something like this), motors can be forced to power off since couple of minutes.