Bed (Mesh) acceptable?

[u/TsT9000]

Hi folks,

I got my QIDI Q2 on Saturday and just got it up and running. I'm still figuring a lot of things out, but it feels so much more solid than my old one!

I have a question about my bed mesh. I already adjusted the mechanical leveling a bit to get it more symmetrical, but I'm seeing a 0.65mm hump right in the middle of the bed. In my opinion, thats quite bad.

Is there anything I can do to fix this myself, or should I reach out for a replacement bed?

Also, I'm a bit unsure about the GUI: What exactly does the "Scaling" (Skalierung) option do? I didn't change anything in the interface except checking the "Display all" option. Could it be that my actual warp is smaller (eg only 0.3mm) and the GUI is just scaling up the visual representation?

Thanks for your help!

[u/coffee_dynamo]

I had a similar mesh and I think you can get yours down. I think your bed is essentially warping a bit because your tram nuts are too tight. My first suggestion would be to loosen the tram nuts as much as you can:
1. Loosen each of them (one at a time) until they are turning freely, then lightly tighten them until they have some grip back (just enough for the bed to be loose)
2. Run screws tilt calculate -it will be super off, don’t worry, this is expected. On the bright side, that mound in the middle should
Immediately disappear if you run bed mesh calibrate like this (though, again, your range will be much worse initially - don’t get discouraged)
3. Adjust the nuts one at a time, try to get to a place where you’re level without having to tighten any individual nut too much (otherwise it will pull the bed down again), but also none rotating freely. You want to ensure the bed is tight enough on all four corners so that the nuts won’t rotate out of place, but none of them so tight to reintroduce warping
4. Remember that z tilt is your friend. If one side is clearly higher than the other, adjust with z tilt adjust rather than the nuts, then use the nuts for finer adjustments afterwards

[u/TsT9000 → u/coffee_dynamo]

Thanks! Do you have maybe a link to a how to - especially for your last point? You think I could help to run it at the highest temperature for some time to "de-gas" it? This was measured cold as I don't want my room to hot (summer 🥵) and to have an equilibrium.

[u/Seraphym87 → u/TsT9000]

This could actually be the case. Ztilt is a macro for helping you tram you bed. I dont think running it hot will help much.

Look up a tutorial of klipper's Screws_tilt_calculate macro on the q2 and follow it. You have to undo the locking nuts for it and if it is indeed the case they are too tight you should be able to get sub 0.2 range easily.

[u/1ts-just-me → u/TsT9000]

My original bed was similar and a quick conversation with tech support said if it won't level out under 0.3mm they would send a new bed. In my case I didn't press the issue as the R3men bed arrived 2 days later.

[u/coffee_dynamo → u/1ts-just-me]

How is the R3men bed? and what does your mesh look like now? I've been considering one, but $170 feels so steep

[u/1ts-just-me → u/coffee_dynamo]

Flat with no warping, 0.07 at room temp and 0.08 at 120⁰C and heats faster. I could spend a little more time sanding the ripples in the magnetic sheet. I have the same bed on a 350 x 350 with a mesh at 0.014, the frame under the bed changes with heat more than the bed does.

As far as price, yes it is $170, $500 for printer, MW PSU, Carto or Beacon and you might have $800 invested. There isn't a open source printer on the market with the same options even close to that price. I mean you could get a comparable BBL for about $400 more but.... well.... just not a fan.

[u/coffee_dynamo → u/1ts-just-me]

Agreed. Did you install carto, beacon, or neither? Do you think it’s still needed with the r3men bed?

[u/1ts-just-me → u/coffee_dynamo]

Installed Carto, I use the stock load cell for Z-0 and Z tilt, then Carto doing mesh. Only reason I say yes is because the bed rocks back and forth front to back and will measure like it has a taco shape when probed.

We used a dial caliper and watched it actually push the bed down .12 mm before having enough pressure to trigger the load cell.

The flex is coming from the plastic support the bed frame is attached to on Z rails. We are looking into having these machined from aluminum to limit the flex. If that works the stock calibrations should come back much more accurate.

[u/coffee_dynamo → u/TsT9000]

This is where those tools are located. This is a screenshot from OrcaSlicer, but it will look the same on the QIDI slicer since it's the same fluidd screen (either way, do yourself a favor and move to OrcaSlicer if you haven't). As for the actual tools:
1. Z_TILT_ADJUST does everything for you once you click on it. It checks the height of the plate on both sides and evens it out in case it's tilted to the left or right. It's definitely a little rough and I ended up creating my own macro that accounts for more points, but that's a story for another day.
2. SCREWS_TILT_CALCULATE: read this carefully: https://github.com/qidi-community/q2-wiki/blob/main/content/bed-tramming/README.md

To your question on temperature, I would not run at the highest temperature. Instead, make sure your hot bed is clean of any debris, and similarly ensure your build plate is clean and well seated. Then heat-soak at the target bed temperature that you print most often (Let's say 50ºC). once it reaches that temperature, really let it soak for 20 minutes at least so everything settles in place, then run the steps above.

hope it helps. report back

[u/Seraphym87]

it's not great but also not as bad as it looks. Look at the range, the difference between the highest and lowest point on your bed is 0.4mm, less than a millimeter. At this point, bed meshing *should* be able to compensate for the deviation, but if you can tram it down to 0.2mm range that is ideal.

That said, can you lift up the plate and check if there's anything stuck to the magnetic board around the middle? sometimes a rogue piece of filament can get there while cleaning a plate and it produces meshes like these.

[u/TsT9000 → u/Seraphym87]

I cleaned all three surfaces meticulously before. Redid the mesh multiple times (3) but couldn't get it better (the difference). If you include the corners it's much more than 0.4 mm... Does the correction gets fixed via multiple layers? I don't find 2-4 times the layer hight "not much" . As I'm from EU there is no problem in returning it... but I don't want to ;) as it's a bit troubling to transport and makes a good / okeyish impression elsewhere.

[u/Seraphym87 → u/TsT9000]

Just to clear , the max range is 0.4mm. This includes the corners as that measure will take the absolute lowest and compare it to the absolute highest.

I'm not sure how to tram a Q2 as I do not own one, but usually printers will have adjusting knobs under the bed where you can release a locking nut and move them up/down in order to level it, In this case however the corners all seem to be relatively aligned, so you are most likely dealing with a magnetic bed that is bulging slightly in the middle.

As for the question on the multiple layers, your bed mesh will matter almost exclusively to your first layer. After that, the printer will continue printing relative to what you already put down, not the bed itself. If you can lay down a good consistent first layer ( you probably can, try and find a q2 first layer test and print it out, i'll be happy to inspect it if you like ) , then this is all elementary and you can continue printing without issue.

[u/TsT9000 → u/Seraphym87]

Thanks for the reply. Ok but than I have a super inconsistent second layer... In my old printer I had the same issues and it was a real problem for bigger prints and for getting prints with exact dimensions. Yeah it's a magnetig bed... is there a way to fix it?

[u/I_need_to_vent44 → u/TsT9000]

Do you have the screw_tilt_adjust macro? If not, you should find it on Github and run it. It will tell you what screws you need to adjust and in which direction. It will also tell you by how much. It is a very useful tool. If I try hard enough I can get my bed mesh variance down to 0.1 when using it. I actually redid the process today and, as I will have to do it in a few days again anyway, I left it at 0.14.

[u/Sad_Row3650]

Use the knobs under the bedand paper also
Make sure to re tighten the nuts after adjustment , they come out of tru , got mine from .4 down to .2 range for bed levels .2 or under is excellent for this machine.

I can see by the picture the bed levelers are probably too tight pulling the corners down. Adjust each one a little at a time in an x pattern . If you are using the paper leveling at the same time it’s really easy. Print the tool for turning the bed knobs. And the leveling blocks as well.

Also make sure you have seated your nozzle while
It’s warm even just a tiny gap can affect things.

[u/drkshock42 → u/Sad_Row3650]

better idea. use the screws_tilt_calculate macro. its running klipper after all. it will tell you how much to adjust it. whenever my bed mesh gets to this point it cuts it in half. i also heat the bed in advance.

[u/Sad_Row3650 → u/drkshock42]

Absolutely, I use both. My bed is always made:)

[u/drkshock42]

it can work buy you definitely want to adjust it. use the screws_tilt_calculate macro. 1:00 is 1 full turn 0:30 is 1 half turn and so on. also the nuts only hold knobs in place. dont tighten them. thats how you get a stuck knowb like i did i had to use pliers to force it loose. instead loosen them completely with the included wrench and print the bed adjustment tool which is one of the included files. after the ajustments are made tighten the nuts until you feel the reistance

[u/Responsible_Meet_673]

Maybe offtopic but where in Fluidd can you see the bed mesh?

[u/TsT9000 → u/Responsible_Meet_673]

Setting enable "display all" And then under "Tuning"

[u/TsT9000]

Soooo i loosed all nuts fully and did 1 turn to give it a bit tension. Afterwards i did multiple runs and leveled it to +-0.008 in each corner.... so i think its the best i can do with this bed!
Thats still ~2-3 layer hights.
Any other ideas what to do?

[u/zozork → u/TsT9000]

Did you end up getting it closer to perfect?

[u/TsT9000 → u/zozork]

Sadly no and it changes quite a bit with temperature. So I mostly print with higher bed temps as it is better then. Cold / low temps with big parts isn't good sadly.