Rough first layer on one side of the bed -- do I need to run bed level correct?  

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

I assume the right was printed first?

What happens if you just print the offending object where the other is? What about when the good one is printed in the bad's location?

Is this repeatable or could it simply have been a bad section of filament? I had a roll of Prusa Black that came with my printer where the first ~3/4s was perfect through a few prints. Then it hit the last quarter about half way through a print and it was a disaster. I've run the same print with other filaments and had no issues so my best guess is that there was simply something bad about that roll 🙁

Have an IR temp gauge you can point at the bed to see if you are getting even heating?

Put a good level (one that is longer than the bed is wide) on it and see if there is a level or warping issue. Measure at multiple places. If it's not level, fix that and try again.

If it was just the bad one I'd say do the "life adjust" to fix your Live Z. The "good" print looks like you could still stand to adjust the Z some, but I don't think that is all that is wrong on the right side.

It also kinda looks like an extrusion issue, but again I would expect that to impact the left as well.

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

Thanks for the response.

I have not yet tried changing the locations of the objects, but will do so and update. It has been repeatable with the same two objects in the same positions.

I just checked the bed temperature using an IR thermometer, and it's essentially the same on both sides (while printing). I'll check it again under pre-heat conditions, to be sure.

I'll also check the bed with a level. Any suggestions on how to manually level the bed if it is not level>

Regarding the Z height on the "good" print, were you thinking it should be higher or lower?

Thanks again.

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

I'll also check the bed with a level. Any suggestions on how to manually level the bed if it is not level>

I ordered mine assembled and have't had cause to look at adjusting the level so I don't know if there is anything built-in you can adjust or if it would just be shimming.

Regarding the Z height on the "good" print, were you thinking it should be higher or lower?

I'm newbie so wait for other input, but it looks like it has some room to drop still.

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

Bed Level Correction is in the calibration menu. Here is the Knowledge base article for it. https://help.prusa3d.com/article/TPGip0OmaP-bed-level-correction-kit-only . All printers should have it since it is in the firmware, not sure why the KB says kit only...

It does look like the right part has the live z too low but the left part looks fine. you could do a couple minor experiments first before adjusting stuff. I suggest you go to the Life z adjust thread in the assembly and first prints subforum and read up and get the calibration stls to use for the tests, they take like 7 minutes to print and are really good to adjust live z more exactly...

My suggestion is that before you go doing the calibration adjustments, start the print again and see if it happens again or not. 💡 Get the printer to temp and let it sit for like 3 or 4 mins before starting the print to ensure everything is heated well and stable. It may not happen again and then no adjustment necessary and the first part could have been affected by strange outside influences that just happen (first part print bed heating, nozzle height while heating)... e.g a fluke.

If it does happen again or if it is a continual issue, then use the live z function to adjust the live z on that part while it prints the first layer and make sure you note the changes and see if it happens on the left part. Then use the bed level correction to adjust. For example if the right part is say 0.15mm lower than the left part (ascertained via your adjustments to live z while printing) and it happens all the time with all prints, then use the bed level correction to adjust the right side by 0.15mm and try again.

Hope that helps.

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

You can easily find out how skewed your bed is.
Do a Self-Test (Calibration/Self test) and then look at the result under the Support menu (Support/XYZ calibration detail).
There you see how big the skew is, a good value is below 0.12°.

Re: Rough first layer on one side of the bed -- do I need to run bed level correct?

UPDATE

First, thanks so much to all of you who offered advice. I really appreciate it.

My bed was not level. After installing Octoprint and the Prusa Mesh Leveling plugin, I could see that my total bed variance was about 1.4 mm, with the bed being lower on the left and higher on the right (thus the problems).

I was able to bring that variance down to about 0.5 mm simply by adjusting screws in the heat bed. (I managed to strip the heads on two of them, but that is a story for a different day.) At that level of variance, using relatively large values for manual bed level correction, I was able to get satisfactory first layers all around the print bed.

After purchasing the necessary supplies, I leveled the bed using the nyloc nut method ( https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_without_Wave_Springs ). I was able to get within 0.05 mm variance pretty quickly. Interestingly, some manual bed level correction was still required to get a good first layer in all parts of the print bed, but the offsets are much smaller than they were before leveling with this method.

All in all, I'm pretty pleased with the results. Thanks again for all of your advice.