Bed Levelness Tuning
I've printed this bed leveling test pattern ( http://www.thingiverse.com/thing:1831902 ) and gotten the attached results. Over my first couple of weeks with my printer, I've noticed the first layer of my prints appearing "smooshed" on the left side of the print bed, while after z-tuning the right side looks nearly perfect. I've tried to fine-tune the z-axis on the left/right, but have reached the max values (-50 on left and +50 on right) with no visible change in my results. My prints are generally turning out quite well, but the majority of them are relatively small and print in the center of the bed. I'd really like to be able to tweak this thing from the get-go, and get a uniform first layer across the entire bed as I attempt larger objects and multiple object prints.
I'm also hoping someone from Prusa3D will chime in. I realize that when I elected to assemble myself, I forfeited official tech support, but my hope was that the company would be active on the forums to help solve problems like this one.
Thanks in advance for any thoughts and suggestions.
Re: Bed Levelness Tuning
Hey there!
Okay, so I had some early on bed level problems myself. Here's what I did:
First off, there's a LOT of plastic going down for a bed level in the print you are using. Seeing that you can only control front, left right and back, you probably should go with a calibration STL of something more like http://www.thingiverse.com/thing:1776031 There's a couple of advantages to this one. The biggest being that the lines that connect each of the squares are exactly 2 lines thick, so you get a "true" representation of what the thickness is going down.
Secondly, and the biggest hang up I had, was thinking that Left: -50 meant that I lowered the bed -50 microns on the left side. Which is actually not correct. According to the manual, that is that you virtually lower the print nozzle -50 microns on the left hand side. Try inverting your negatives and positives in that menu and see if you get a different result.
Let me know if that helped you out!
Re: Bed Levelness Tuning
Thank you very much for your response. Feeling very bone headed in misinterpreting the bed height vs. nozzle height.
Life intervened, and this got away from me tonight, but I will post again tomorrow night with an updated test using that pattern that you recommended. I'm going to cut it down to one layer, just because it's useful to me to see how that first layer goes down. But I printed a small piece tonight, and reverting the left/right values already seems to have improved things a lot.
Feeling a bit boneheaded right now. : )
Re: Bed Levelness Tuning
Thank you very much for your response. Feeling very bone headed in misinterpreting the bed height vs. nozzle height.
Life intervened, and this got away from me tonight, but I will post again tomorrow night with an updated test using that pattern that you recommended. I'm going to cut it down to one layer, just because it's useful to me to see how that first layer goes down. But I printed a small piece tonight, and reverting the left/right values already seems to have improved things a lot.
Feeling a bit boneheaded right now. : )
No need to feel boneheaded! The verbiage of the menu really makes you think you're adjusting the level of the bed, not of the nozzle. You shouldn't need to limit the layers on the print I suggested unless you are printing at sub .2 mm layer height. (which I wouldn't recommend going below .2 for calibration purposes.) IIRC the print is exactly .2mm tall. Makes slicing and such really easy to get calibrating.
Re: Bed Levelness Tuning
Thanks again for the suggestions. Last night I got to tinker with it and the infill is looking much smoother on all the squares. I also obtained a digital caliper and the thickness of the print came in at 0.202mm, which is within the margin of error for the calipers. Cool stuff!
Re: Bed Levelness Tuning
You can overcome most issues by using a raft.
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: Bed Levelness Tuning
You can overcome most issues by using a raft.
How so?
I found rafts mostly useless and a complete waste of material. That is when trying to print large parts that are structurally strong.
Re: Bed Levelness Tuning
You can overcome most issues by using a raft.
How so?
I found rafts mostly useless and a complete waste of material. That is when trying to print large parts that are structurally strong.
The idea is that even if your bed is shaped like a picasso fruitbowl, after slathering it with raft, you have a plane surface.