[Cerrado] Left side vs right side of bed  

Re: Left side vs right side of bed

Can you record the printer doing an Auto home function. The reason i ask is that it seems to be a reasonably good indicator of how well everything is aligned.

I would also flip you printer on it's side and check that the Y-axis is threaded rod is nested in the Z-axis frame evenly.

Re: Left side vs right side of bed

I have the same problem, I also made a thread but no solution, yet. The only thing that works for me is to turn the right z-axis motor after the auto calibration a bit down by hand and turn it up again after the print.
I think there is an offset in z-axis of the calibration points in the bed. Are there inserts or something pressed in the bed, that the pinda probe detects or how is it working? If there are inserts.... When these inserts are not 100% correct pressed in the bed on the right hand side, the pinda probe would detect that the bed is higher than it really is. But thats just a theory 🙂
Here is my thread: http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/calibration-problem-t940.html

Re: Left side vs right side of bed

Hi guys, we've worked last couple days on the updated manual.

http://prusa3d.com/3dhandbookMK2

Please take a look if it solves your problem with calibration.

Re: Left side vs right side of bed

Hi Patrick!
I did read your post but it was before I had this same issue.

I know that your method of fixing the misalignment isn't ideal but it is at least working for me temporarily until I troubleshoot further. I simply manually screwed one side down a little bit. I then took a ruler and ensured it was parallel. Now I am actually printing bigger than the whistlefor the first time!

I think my issue s with the Z axis. The Z screws never bring the X axis all the way to the top. I first had my trapezoid nuts on upside down. I fixed that this morning but it still doesn't go past 94mm high. Yes it's in hi power, there doesn't seem to be anything mechanically blocking, etc. When I figure it out I'll share that too.
Thanks for the tip.

Re: Left side vs right side of bed

Hi guys, we've worked last couple days on the updated manual.

http://prusa3d.com/3dhandbookMK2

Please take a look if it solves your problem with calibration.

I just had a look at the changes this is far better than what was there before, I probably would have prevented the damage to my bed. In saying that I have my PINDA probe down about 1mm lower than what is described in the handbook. I'll have a go at adjusting it upward tomorrow. I had a very similar issue to the one described in the video, basically it would stick the plastic onto the bed for about 30mm of the calibration process then gradually rise up for the remainder of the journey. I never had it stick as well as it did in the first 30mm anywhere else, so i never thought of it as a right hand vs left hand side issue.

On another note to do with right hand side calibration, I found that with the default cable configuration occasionally resulted in the extruder cable getting caught on the Y-axis cable, this would cause the calibration to fail occasionally. The extruder traveled across the X-axis, there would be a slight grinding noise and it would stop ~20mm from the right hand side. You can see when it stopped on my bed to burn a little hole in the PEI at different points, https://imgur.com/ULZchw7 i even have a boat imprint, from when i wasn't paying attention and it printed while ramming the head into the bed. The really annoying thing is that it wouldn't happen every time, only when the cables got tangled. I have tried to fix it by changing the y-axis cable ties so that they don't try to pull the y-axis cable upright as much. https://imgur.com/LXVRbxY I'm using 2 cable ties, one on the case, one looped through the spiral wrap.

So the full list of changes that I did where,

* make sure that x-axis end stop was making good contact.
* make sure that the lines were parallel, i had to move the RHS of my frame about 1mm. I measured it with calipers I found 2 nuts that i could use to measure from hopefully avoiding any miss measurement due to uneven plastic surfaces.
* fix cables dragging on each other. extruder & y-axis cables.
* drive x-axis to the top of the z-axis to ensure that they were level.
* make sure that the gear on the x-axis is tight and that the screw is sitting firmly in the flat part of the axle
* make sure the cable ties on the bottom of the print bed aren't touching it.
* unscrew the top right hand side of the z-axis, then make sure that the x-axis is together correctly, then screwing on the top on again, which was much easier than during the initial construction.
* the belt on the y-axis was being driven into the gear of the stepper motor, so i cut it a bit shorter.

The first time i managed to get anything to work correctly i had adjusted the PINDA probe down too low, so i moved it up enough so it wouldn't make contact with the plastic being extruded.

After doing all that, it works, but I have no idea why it's working. I have my z-axis off adjusted to -1.5mm or something, it's quite massive because of my PINDA being so low.

Re: Left side vs right side of bed

I am having the same issues only my left side is higher then my right side. During calibration right side get squished onto the bed good, left side not. I can't compensate for that with z level, because right side will be to low then.

Checked all the things mentioned in this topic. With small objects I have no issues, i calibrate the right side correct and print there.

Does this have to do with level of the x axis?

Putting spacers between the top left side Z Axis and left X mount doesnt seem to work (this tilts the axis), the auto leveling takes care of that I think.

More ideas?

Re: Left side vs right side of bed

I am having the same issues only my left side is higher then my right side. During calibration right side get squished onto the bed good, left side not. I can't compensate for that with z level, because right side will be to low then.

Checked all the things mentioned in this topic. With small objects I have no issues, i calibrate the right side correct and print there.

Does this have to do with level of the x axis?

Putting spacers between the top left side Z Axis and left X mount doesnt seem to work (this tilts the axis), the auto leveling takes care of that I think.

More ideas?

Mine is exactly the same! Left side not touching the bed but right side touching and putting pressure on the bed during calibration. This is frustrating.

Re: Left side vs right side of bed

Is your Z axis level todd?

Re: Left side vs right side of bed

Hi Patrick!
I did read your post but it was before I had this same issue.

I know that your method of fixing the misalignment isn't ideal but it is at least working for me temporarily until I troubleshoot further. I simply manually screwed one side down a little bit. I then took a ruler and ensured it was parallel. Now I am actually printing bigger than the whistlefor the first time!

I think my issue s with the Z axis. The Z screws never bring the X axis all the way to the top. I first had my trapezoid nuts on upside down. I fixed that this morning but it still doesn't go past 94mm high. Yes it's in hi power, there doesn't seem to be anything mechanically blocking, etc. When I figure it out I'll share that too.
Thanks for the tip.

Hi Keri, could you try this ?

Unscrew a bit the two screws holding the trapezoid motor nuts so that it's loose, and try moving the Z-axis to the top. There are chances that the trapezoid nuts is not well aligned.

Once on the top, tighten the screws and try to go down and up again to validate if it fixed it.

Re: Left side vs right side of bed

Is your Z axis level todd?
Yes, Z axis is level. I also double checked that the bed is mounted firmly in the frame and making contact all the way with the threaded rods to frame.

Re: Left side vs right side of bed

Hi

Are you sure about the perfect rectangular shape of your Y axis ? I had the same issue and notices that my rectangle was not that rectangle : right angles were not that right and the distance of the smooth rods were not exactly the same from one side to the other. I put the printer on the side to fix the M10 nuts and obtain a good rectangle. Now things are much better.

Re: Left side vs right side of bed

Is your Z axis level todd?
Yes, Z axis is level. I also double checked that the bed is mounted firmly in the frame and making contact all the way with the threaded rods to frame.

Todd, did you ever resolve this issue? I'm have the exact same issue, right side is squished, left side isn't adhering. I've reset the bed into the frame multiple times with no change. My probe is dead center in every circle as well. I'm kind of at a loss, I'm almost read to rebuild my y axis.

Re: Left side vs right side of bed

Matt

Have you tried running the bed calibration using the latest 3.0.4 firmware?

Peter

Re: Left side vs right side of bed

Matt

Have you tried running the bed calibration using the latest 3.0.4 firmware?

Peter

I did run it and it actually misaligned the probe so one edge was just outside of the dotted lines, so I didn't end up trying to print with it. I'll rerun the calibration and try a print.

Re: Left side vs right side of bed

Matt

Same thing happened to me, but the key here is that it is supposed to find the best trigger point for the probe.

Run the bed calibration again, leave it calibrated and see how things go.

Peter

Re: Left side vs right side of bed

Matt

Same thing happened to me, but the key here is that it is supposed to find the best trigger point for the probe.

Run the bed calibration again, leave it calibrated and see how things go.

Peter

Will do. Thanks PJR.

Re: Left side vs right side of bed

I ran the calibration and then the calibration gcode, it's maybe a little better but there is still a pretty obvious difference visually and in adhesion.

Re: Left side vs right side of bed

Matt

Apologies for taking you through all that. I have the problem at calibration point 3 where the nozzle pushes the bed down. I believe that the problem is due to the probe insert not being placed with sufficient accuracy.

I am currently trying to get hold of a replacement bed, but until that arrives, I am trying to ensure that first layers miss out the front right quarter of the bed.

Peter

Re: Left side vs right side of bed

Matt

Apologies for taking you through all that. I have the problem at calibration point 3 where the nozzle pushes the bed down. I believe that the problem is due to the probe insert not being placed with sufficient accuracy.

I am currently trying to get hold of a replacement bed, but until that arrives, I am trying to ensure that first layers miss out the front right quarter of the bed.

Peter

No problem Peter, I appreciate the help!

Has anyone had this issue and actually resolved it? If you have, what did you do? Looking for ideas.

Edit: I'd just like to add that the smooth x rods are parallel with the bed lines.