Hi, I have been having an issue with my first layers when printing with the Mini 2. So the problem is basically this. The left side of the print bed would have smushed layers and the right side of the print bed would have layers that don’t stick. It has taken be a while to figure out the issue because I thought it was related to the X-axis drooping on the left side and I thought that auto-leveling would compensate for any unlevelness in the print bed. However, I just measured it and the left side of the print bed is indeed 1mm higher than the left side. Before taking this measurement I leveled the x-axis an moved the z-axis down to where it is just touching the center of the left side of the print bed. I then moved the x-axis to the right side of the print bed and then lowered it again until it started touching. I was careful to do this only 0.1mm at a time. I also double checked that the x-axis is still level after this by measuring from the bottom end stops of the z-axis on both sides with calipers.
So I guess my question is this:
Is there an easy solution to this problem? I can’t quite determine why the print bed is uneven.
Why is the auto-leveling not compensating for this? Is this somehow too big of a difference? I have made sure to clean the nozzle before printing and I still see this issue.
Thank you,
Dakota
While your bed may be tilted,] I wouldn’t use the x gantry as a means of determining this. Particularly on the 2, which can be unreliable even after tramming. You should measure the bed from the frame assemblies: the lower Z axis mounts are probably good for this, allowing you to run a straight edge from either side over the bed and then measure between that and the bed surface for example. Probably also a good idea to measure down to the metal frame surface as well and compare.
I would also make sure that the tramming/x levelling process on the 2 is accurately bringing the gantry level, and that the homing process after tramming is not introducing a subsequent tilt. My Mini 2 had a little printed belt stay that held the looped end of the X axis belt on the left side. This part was sitting slightly more to the left than it was designed for, and would hit a recessed portion of the X motor mount and force the left side of the gantry down very slightly when the printer homed. Result was a print head that was always slightly tilted to the left after homing. That was fun to solve. 
If your bed is actually tilted that much relative to the frame of the printer (which is a lot for a mini) you can use shims to physically level the bed. I think the bed tilt process in marlin (I’m on klipper now) is good for something like a 0.5mm error. Anything over and it’s not fully fixable in software. I had this issue with my Taz6 bed and used the process outlined in this thread to get things levelling consistently.
Thanks for the suggestions!
I ended up printing some 1/16" shims that I found on thingiverse. They ended up coming out at 0.7mm for whatever reason. It is not perfect, but it is better than it was. It is a good solution for the interim, but I would like to model my own sometime in the future and design them exactly to the specifications that I need.
On another note, how did you get Klipper working with the mini 2? Did you make your own config? I was interested in switching over but I was unsure of the amount of work involved if I were to make my own config for the mini 2. I don’t have enough time as it is, but amusingly enough I have been considering redesigning the entire x,y, and z axes to use linear rails because I don’t like the amount of slop in the rods. Also, I think the space is poorly utilized on the mini and all the 3d printed parts could be smaller. For example, it seems like the hotend could be closer to the x-axis, the current design has the hotend cantilevered quite far off of the x-axis which results in movement of the hotend when homing. Also, the z-axis needs a gearbox.
I rolled my own klipper config for the mini2. Happy to share if you’re interested. I run klipper on all my lulzbots, as I have zero patience for running Cura LE and even less patience for the nozzle-abusing Lulzbot bed levelling and wiping sequence scheduled prior to every print.
Agree on rod slop. I literally have a linear rail X gantry for my OG mini designed to run EVA tool heads printing as I type. The OG mini is a truly reliable workhorse printer out of the box. Not fast, but just old-school Correct. But the X carriage is enormous, and the rods take up a lot of space for not a lot of stiffness. Also agree on the disturbing lulzbot tendency to cantilever the S*** out of every tool head.
My taz6 uses a shortened version of the excellent M1.75 toolhead from Lulzbot, but running a dragon hotend. (this BTW is why I have a soft spot for lulzbot, because the open source documentation is STILL worth it) I modded their design to bring the nozzle closer to the gantry. I run a fully-custom toolhead on my Mini 2 that utilizes an orbiter geared extruder and a dragon hotend.
Both of these print SO much better than the aerostruder versions they replaced. Night and day. Less ringing, faster and more consistent printing. Simple and fast mesh bed levelling with BLTouch sensors.
Also, getting back to your bed levelling issue. As you have discovered, Lulzbots have no built-in adjustability as far as bed levelling goes. This is good and bad. If they are level, they will tend to stay level as long as you don’t get rough with the bed. But if you have to pry parts off – say, like you are prone to do with PEI beds – then you constantly need to relevel. So the single best upgrade I have found for lulzbots is a spring steel sheet. I run ones from printed solid which are very cheap for the minis. These let you pull the whole bed off to remove parts, which means the bed level rarely has a reason to change. Highly recommended.
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It would be much appreciated if you can share your mini 2 config. I assume I will need to pursue a different bed leveling solution when I make the switch over. I will probably need to redesign the aerostruder toolhead to accompany bltouch sensors.
I also have the spring steel sheet for the mini 2 installed on my print bed. I agree it is a much better solution. Part of the reason I decided to go with a lulzbot was because they offered a spring steel bed upgrade. I was tired of finicking with the bed on my monoprice maker select v2. Ironically I still get better 3d prints out of it than my mini 2 despite being 1/3 the price. However, I agree, open source is still worth it, but if I would have known that I was going to have this many issues I would have just built a voron.
I’ve been having an x axis leveling issue as well with my recently purchased Mini2. The right side always seemed lower no matter how many times I would level the x axis. I also had to tune my Z offset prior to every print. You may want to roll back the firmware to marlin 2.0.0.144. I did so after installing the M175 tool head. Bed leveling probing is much smoother and the leveling issue is gone.
Indeed, I have since rolled back my firmware. It helped a little, but I think the root of my issue is still that my bed is horribly unlevel I have since given up on my lulzbot mini and plan to sell it. I was just unhappy with the print quality that I was getting. My old monoprice maker select V2 prints much better. I’m currently in the process of building a Voron right now. All I have to do is finish up the electronics and then I’m done.
Hi, could I get a copy of your Klipper config? I had tried a while ago and ran into no success.
