Unknown stoppage and Y skew [RESOLVED]

I started printing tonight and about 80% through my build my M90 had stopped?! It was an SD print so no messages on Pronterface and when I went to investigate it seemed that Pronterface was disconnected (but I believe that to be usual). I have no idea why it stopped and was wondering if there was a way to find out? If it helps, it extruded fine after I removed the item from the bed and the failed state was with the extruder sat on the item not parked somewhere else, almost as if it was paused.

Also, I printed a handle for my bed scrapping blade, just a quick model I bunged together. I set Skeinforge to the usual 0.3 PLA profile and got a clean G file but as it started to print I noticed it seemed to be skewing in the Y axis. In the picture you can see that as the layers are added its building it more and more in the +Y direction. Is this a bed leveling issue? I only ask as I leveled the bed on day one which was only last week! I wasn't expecting to calibrate for a little longer yet

EDIT: Marked as resolved.

Edited 1 time(s). Last edit at 11/03/2013 12:39PM by setherith.

No it isn't a bed levelling issue. Looks more like a loose pulley, or belt.

Have you removed the auto reset jumper. If not it will reset the Melzi when the USB connection fails.

---

[www.hydraraptor.blogspot.com]

Hey Chris, thanks for getting back to me so quickly. I checked my belts and only my X belt was a little slack so I tightened it back up with the adjuster. Not sure if the X belt would have resulted in the Y skewing but I'm about to start another print in a moment so I'll let you know how that turns out.

Your right, I thought I had removed the reset jumper but it seems I must have put it back on at some point as its still in place. My first thoughts on this issue was "I wonder if my computers' USB sent some sort of signal to interrupt the print?". I guess I'll find out when I try to repeat the print later today.

By the way, the guys at work love the results I've shown them at PLA 0.2 profile, I reckon some will be buying from you soon

I printed the calibration part as per your manual to test my X belt tension and it seems a little better than before (see picture). But its still not 100%, I'm a little worried about over tightening the belt. It's playing a low note when strummed as per your instructions in the build manual.

If it is sloping in the Y direction and only in very small steps it is probably a loose Y pulley. Mark the pulley and shaft with a felt tip pen and see if they more relative to each other to be sure. Or try rotating the pulley with the motor powered and see if it slips.

If the belt slips it will be multiples of 2.5mm. If the motor skips steps it will be multiples of 0.8mm.

The tension on the X belt will have no effect in the Y direction as the two axes are completely independent.

---

[www.hydraraptor.blogspot.com]

Well so far several prints in without the jumper in place and I haven't had a stoppage so I think the first issue is resolved.

As for the second issue your assumption was correct, I had a loose pulley, it was able to slip up and down the motor shaft by a couple of millimeters so have tightened it up and am not testing with another print.

Will let you know how I get on...

Brilliant! Thanks a million! I adjusted the pulley and it now prints straight up see pictures attached.

They are a tight fit, but they fit and are now bedding in nicely!