Rostock v2 Head goes nutty during prints

[Toysrme]

Rostock Max v2.
After several layers, ultimately at some point during all my prints the print head moves off to a side & tries printing items offset. I have no idea why.

I've cleared & reflashed firmware
Checked the physical setup (Towers, belts, hot end, heat bed level & down snug) tried different RH's, all different slicers & frontends (RH/Slic3r, MatterControl, Cura, etc et al)
Run Calibration over & over & small calibration objects / prints are ok
Tried all the stock nozzles .35/5/7
ABS & Taulman Bridge
The prints & alignment is always fine for 10-30 layers & then just... Like everything migrates over an inch.
USB connection live from RH or MatterControl and straight from an SD card., same results.


I'm just not sure what's going on or where to begin looking at this point.

[Mac The Knife]

Check the set screws for the drive pulleys.

[Toysrme]

yes they are set, belts have good tension, the towers are as square as i can make them & snug. bed, head, everything that can be that i can think of physically is ok.

still happening :/

[Earthbound]

Please post a picture of the machine with the effector centered at Z0.

[DavidF]

any chance you could be getting snagged on the print,causing the printer to loose steps???

[geneb]

David, if it was snagging THAT hard, it would've torn the print right off the bed.

g.

[Dad003]

after some printing at around 240-245 the peek fan just meltdown ... that maybe what your getting right now if everything is good

[DavidF]

David, if it was snagging THAT hard, it would've torn the print right off the bed.

g.

Have to disagree, I've had mine get snagged up several times without dislodging the print from the bed. And they were not huge prints either.

[Toysrme]

it doesnt grab the prints; for reasons i dont understand it seemingly arbitrarily just moves the prints over at the start of the erroring layer.
oddly, if i enable the spiral vase setting in matter control it wont do it.


its not grabbing / the belts are not having teeth jumped. obviously a firmware glitch to me when 5 slicers and 4 front end GUI's cant get together & make something work.


FWIW on the glass using 90* on abs and 48* (cooling to ambient after 5 layers) on taulman bridge, ive only had a few prints come off of purple PVA stick. one was simply warpage due to the uneven temp of the stock v6 bed+glass (needs a heat spreader). i simply avoid printing long objects to that quad

[Earthbound]

Based on everything you've described, it would have to be a hardware problem with your machine.

1. Happens on all of your prints - I'm trusting that you've tried more than one model, so we can rule out bad files.
2. You've reloaded the firmware, so corrupted firmware is off the table. Others print without this issue, so firmware source is well validated.
3. Can't be material related.
4. Any physical interference of head or layer fan against print or umbilical/wiring snagging on arms or hot end would be noticeable and probably have some noise associated with the event.
5. Belts are snug and in good condition?
6. Screws for idlers at tops of towers are tight?
7. Set screws on gears are tight?

8. I think it is heat related. Possibly one motor driver getting hot and causing motor to lose torque briefly. Does shift in print occur in direction opposite of one tower? Try to temporarily blast more air against the back of the RAMBo and see if the result is different.

[Toysrme]

Everything I can find is tight, I loctited them down during the build with perminent. Belts are are snug & in good shape (I can't make them skip a tooth by pulling them quickly), likewise all the skates seem to have the same tension as far as I can tell.
Ya I've had some prints come out fantastic. Printed a large vase out of Taulman Bridge that went great. I've checked models in meshmixer for holes.
Physically nothing is snagging. I recorded a failed print on my gopro a few days ago & there wasn't a physical skip / dive into the model. It's like when it started a layer it simply started it moved over & rotated by a few mm.


Ill leave the covers off and a spare computer fan towards the motor drivers on the rambo. If that works for awhile Ill heatsink them.

[PrintableStudios]

Everything I can find is tight, I loctited them down during the build with perminent. Belts are are snug & in good shape (I can't make them skip a tooth by pulling them quickly), likewise all the skates seem to have the same tension as far as I can tell.
Ya I've had some prints come out fantastic. Printed a large vase out of Taulman Bridge that went great. I've checked models in meshmixer for holes.
Physically nothing is snagging. I recorded a failed print on my gopro a few days ago & there wasn't a physical skip / dive into the model. It's like when it started a layer it simply started it moved over & rotated by a few mm.


Ill leave the covers off and a spare computer fan towards the motor drivers on the rambo. If that works for awhile Ill heatsink them.

This sounds like you are missing steps.

As mentioned above, it could be stepper drivers shutting down due to thermal conditions.

If you heatsink the chips, I believe these are best done by adhering them to the bottom of the board below the chip, as opposed to directly on the chip, but would need to pull the datasheet for the driver to confirm.

[Herman]

Hi Toysrme,
This is bad, I hope to ask some relevant questions.
Do you (ever) get exactly the same result from exactly the same model? (is the error reproducible?) then it could be a (arrhythmic) processor or memory error. Probably not a virus.
I think the system has a power saving mode that cools down idle stepper motors and H bridges, but they heat up when (re)starting movements If you've been printing a while does one motor feel more hot then the others? or do they all overheat? motors should not heat-up to the point that you can't keep holding on to them, usually you cannot burn yourself ever on such motors. Overheated motors demagnetize temporarily and even permanently. If lubrication or friction would be your problem it wouldn't make much difference early on or later in the process.
it is harder to see temperature on your controller board but maybe it is possible to use an extra NTC resitor to connected to extra Thermistor inputs to measure electronic components on the controller board to, especially the H bridges and freewheel diodes. you could use small pieces of kapton tape to fix them to suspect parts. Otherwise changing a controller board would not give you any certainty of success.
Is your hot-end or your onyx shorting out to the point that most of the heat is dissipated in the wires or in the PS this could reduce in an erratic way the voltage for the motors and the maximum torque the motors can generate. The PS should overheat and the average voltage (12 VDC) should drop some. It is hard to measure without an oscilloscope, but with luck you should see something with a simple digital voltage meter or a more universal DMM. This is less likely because it doesn't explain the good start.
An other thing I got when building my Rostock Max V2 you have to carefully avoid interference between the end switch wires and the wires to the hot-end and to the extruder-steppermotor. If you have your wires in tho "loft" hanging loose and you have had it stored while not in use then probably they have moved around and could now be in a bad place picking up more interference then preveously. The extruder motor has more current switching pulses, but they are there from the beginning. The hot end however initially has little heating to do as the starting temperature is at equilibrium and no plastic was flowing jet, but after 30 -60 seconds it must react with extra heating so a lot of duty cycle switching is going on. If your limit switch wires are in parallel to the hot end wires then you could be having this problem. It also explains why no vertical displacement is noticeable, the joined limit switch wires all feel the same interference and all motors stop at the same moment and restart with the same delay. I'm not sure if the software is able to detect that and stop with an error, but it doesn't have to be. I don't see an error when the skate bumps into the limit switch when a home issue is making them go upwards.
By having the wires cross each other exactly perpendicular it can not be from magnetic interference and the frequencies are way to low for capacitive influencing.

I hope this gives you some hints to find more unlikely bugs. Good luck, Herman.

[626Pilot]

Print this in vase mode and take a picture. It might help us diagnose better if we could see precisely what's happening.

http://www.thingiverse.com/thing:139113

I had a problem where I couldn't print anything over a few centimeters. Changing arm length in firmware allowed me to get my prints taller. Eventually I was able to print that whole cylinder.

[greglee101]

It looks like this problem remains unresolved. I am experiencing the same problem with my Orion. I have tightened the belts and reflashed, you name it but still have the problem on big prints. It is not consistant and I expect it is something like heat. To get things working I simply slow down the prints. In some cases down to 20mm/sec. This takes a long time to print but seems to reduce if not eliminate the problem. The side benefit is that the quality and strength due to better bonding is better.

If you come up with a solution I would be most interested.