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I'm very near the end of a Max build, and everything has been going well until I got to printing the first fan shroud.
The first layer goes down fine, but then the next layers shift about a centimeter to the right. It looks like the nozzle isn't traveling up for the next layers, and is just dragging on the first layer until it gets dragged off course. The slicer settings are the recommended abs settings. I checked and loosened up the cheapskate carriages, and tried to get all my belts tightened to the same tension. The joints on the arms seem to be good, and bearings and pullies seem to be ok as well. Any other ideas on how i should proceed?

I think your assessment is correct - the head isn't moving up after each layer.
It also seems like your first layer is pretty squished too, perhaps the Z height is incorrect? Have you run through the LCD Z height calibration? Just a thought but it could be that it is actually moving upwards but since it started 'below' the bed height it's just printing a z=0 for a few layers.
Let me know if you've done the Z height calibration from the LCD.

I haven't done the LCD Z height since I did the rest of the calibration. I'll try again and let you know. Thanks.

Still no luck. I recalibrated z hieght from LCD, and the first layer looked good, less squashing of the material. I tried to let the next print go to see if it would recover eventually, but each subsequent layer falls to the right. Should I just try the full calibration for all the towers again? I also re-sliced the file, and have tried printing from the computer and just from the card. Ideas?

This looks like a classic example of slipping belts or pulleys. Make sure the pulleys on each of the steppers are secure and that the belts are tensioned properly (per the manual) and are not slipping.

Forgot to add, pay attention to the direction that the shift occurs. It will typically be towards/away from one of the three towers. Guess which one is the culprit in this case? Yup, the one the shift is towards/away from.

try going z0 and home a couple of times and look for which stepper is lagging behind. Are all the set screws tight on the pulleys??

I've discovered what could be the issue (and will feel dumb if it is). My top plate wasn't seated correctly on top of the right tower (towards where the prints were shifting), making that pulley a full 1/4in higher than the others. On top of that, the microswitch came missing it's little spring lever, so I thought I could make due by putting a little bent piece of metal at the top of the skate to strike the button switch. That left the skate a little lower than the other two when it fires that switch. I'll have a new microswitch Monday, and hopefully fixing all that along with a fresh calibration should fix my problem. Does that sound like it could cause this kind of problem?

Well glad you figured it out. Don't worry and don't feel dumb, I've done dozens of things that made me feel really dumb with my Rostock - you get used to it

ScoJo wrote:I've discovered what could be the issue (and will feel dumb if it is). My top plate wasn't seated correctly on top of the right tower (towards where the prints were shifting), making that pulley a full 1/4in higher than the others. On top of that, the microswitch came missing it's little spring lever, so I thought I could make due by putting a little bent piece of metal at the top of the skate to strike the button switch. That left the skate a little lower than the other two when it fires that switch. I'll have a new microswitch Monday, and hopefully fixing all that along with a fresh calibration should fix my problem. Does that sound like it could cause this kind of problem?

Sure sounds like you have discovered the problem. Good troubleshooting!

Hey all. So I put in a new end stop switch, tightened up my belts a bit, and did a fresh calibration, which went well.
I resliced the model, and started the print again. Still no luck. Same issue as before. The nozzel doesn't seem to be raising for each layer, and gets thrown off when it zips across and bangs into the previous ex layer. I'm running out of ideas.

Just out of curiosity, are you remembering to put your new Z height into Repetier/Matter Control? As McSlappy mentioned, it almost looks like it's pushing the nozzle down too hard.

Was there any difference in shift after the belts were tightened?

Is the shift always consistent with the same tower?

I'm pretty sure I entered the Zheight into Repetier. I didn't do a correction for the convex/concave, but the nozzle was a bit low--not pinning the paper, but def a bit more resistance. The shift is always to one side, and happens on the quicker moves, and seemingly as the result of colliding into previous layers. The shift varies, depending on when it gets pushed. That said, the shifts aren't quite as dramatic since tightening the belts. I'll get them a bit tighter maybe (they aren't as tight as the ones on my Orion). One side (The side in the direction of the shift) is higher, the other side has all its layers squashed into the plate. At most I get 4 layers before the nozzle is digging into the plastic and I have to abort. My most recent prints lay down a proper first layer--not so squished. I'll go back and make sure I've entered all my numbers correctly in Repetier, and maybe try printing a cube or something other than the fan shroud.

Im away from the machine until the weekend, but your ideas and help are greatly appreciated. Thanks so much.

OK, so I found another problem--my belts were threaded incorrectly around the bottom, and after correcting this, the skates move so much better, and I thought surely that was the issue. Over the weekend I reinstalled and set up Repetier from scratch, calibrated again,tried slowing down the prints on the non printing moves ( to perhaps diagnose any slipping). Printing slower, the print is better, and does seem to be lifting for each layer, but each layer shifts to the right. Nothing I do seems to affect the problem. I tried printing another file, with the same shifting results. Anyone have any other suggestions?

Solved!
After much forum searching, found this topic:
http://forum.seemecnc.com/viewtopic.php ... set#p29972

That's it. The ezstruder stepper was wired and routed along side my y end switch, causing the stepper to pause and throw everything off. In the end, I'm glad it happened, as it forced me to examine and clean up my previous work.
Thanks everyone for help. Prints are coming out great! Second pic shows wire( now hanging outside machine. Was thinking of leaving it as a battle scar, but will probably rout it thru another tower soon.

I am glad that you found the solution. I think the manual warns against running end stop wires near the stepper wires but we all make mistakes.
You were good enough to share your mistake with all of us which should help anyone building a new Max. Thanks!