[Solved] RepRapPro Mendel Y Skip

[Solved] It was belt tension. I had run out of adjustment room on the y motor bracket so had to dismantle the bet and pull the belt a bt tighter through the clamps. Seems to have cured to problem. My tension now seems to match a couple of 'belt plucking' videos on youtube!

[Update] RRP support suggested that while printing ABS the heated bed might have softened the PLA belt clamps, leading to a loose belt. I did think the belt clamps looked a bit soft/curved when I tightened the belt. So will try alu foil between the mdf bed and the heated platform (which may also help keep the bed temps high).


Hi RepRapper,

I've seeing a new issue on long print runs (with ABS) with my RepRapPro Mono Mendel. After a couple of hour I start to a see random skips in the Y axis. It starts printing anything from a few mm out to 1 cm.

The bed moves freely and I've rechecked the y belt tension and tried again and see the same issue. I've also limited the travel speed to 100mm/s and I still see the problem. This is various models sliced in Slic3r 0.9.9

[edit] Video clip HERE

Any ideas ?

Cheers

Rob

Edited 3 time(s). Last edit at 08/30/2013 08:28AM by pocketmoon.

I've had similar issues in the past with different causes on my Prusa. Try a different slicer, host, and OS/host computer (if you are using one). Also check to make sure the pot is turned up enough on the Y stepper motor.

I've just stuck a camera above the y belt drive and then just used my 'goto' levelling buttons on pronterface to move the bed back and forth. I've no idea what's happening 6 seconds into the clip! Massive jarring.

Video Clip of Issue

Anyone seen this type of issue before ?

gcode is not being properly sent to machine, or properly processed on the machine. its last feedrate is no longer in memory, and another code is sent to move axis, and the code is not properly formated with feed rate information, or feed rate is being over writted from a buffer that is too large. Software likely is falling back to slowest feed rate it can run.

look at gcode and ensure that every line used has a Fxxxx to the end of it. then look for comm issues, what baud rate are you running at, and also look at how much memory your device is using has. What hardware are you using and does it have enough ram?

Just a guess, but likely it is an error of something not working right in the electronics, and it seems like it is not mechanical, as long as your pulleys are not slipping of the motor, and the bed can slide back and forth when electronics are off.
not working right, and it seems like it is not mechanical, as long as your pullys are not slipping.