Bed issues with ABS

Hello all,

I’m in the process of learning with my new (to me) Lulzbot Mini and was hoping for some suggestions on trouble shooting a problem I keep running into when I’m trying to print with ABS.

The first is that the skirt doesn’t seem to want to print easily. If it’s at a line count of 1 then it tends to be very thin, hardly stick and get caught in the extruder head as it passes between pieces on the table. I tried a thread count of 3 and got this:

Once the printer starts to print the actual project it seems to go pretty well except for…

The other problem I have which is that the bottom of my prints, that are touching the surface of the bed, are a little wavy and seem to have a corner that is coming up away from the bed. Otherwise my prints seem to be fine.

My settings for the head and bed temp. have been 145 for the head and 115 for the bed. (I’m a bit worried about a draft that I haven’t boxed the printer off from yet.) Is the bed temp. too high? Is that why it isn’t sticking?

I am out of isopropyl alcohol right now but will be picking up some tonight to clean the bed with. I also have sandpaper from 2000 up to 8000 grit to softly sand the bed with as well.

Thanks in advance for any help or suggestions. It’s been a very positive experience so far with only these minor hiccups so far.

Well hard to say, but on first glance it sounds as if your hot end is just slightly too far away from your heated bed. If that’s the case your ABS will not stick very well and you will have more problems with the corners having curling and warping.

Try adjusting your z-offset to slightly closer and see if that helps.

I think the autolevel is off… As Biolumo mentioned, the side that’s lifting indicates the nozzle is too far from the bed. Adjusting Z-offset is a good check, but it will also affect the side of the print which has the correct initial nozzle to bed gap. Essentially the base will be expanded or flare out due to the squash.

Not sure how to fix this if it is the autolevel… you seem to have the reverse problem most people have. :slight_smile: I guess you should check that all the washers are screwed down. Then check that the washers are clean. The firmware uses the three touchpoints to determine a print plane. If one touchpoint is off, then the print plane (nozzle height) would be skewed.

Looking at your pictures again, is your PEI bed bubbling?

I hope you meant 245C :laughing:

What do your auto level numbers look like?

It’s possible that one of your z-axis lead screws is turned. Check each side of your z-axis. That is measure from the top rod of the x-axis (the rods that hold the extruder) to the top of the printer. Do this on each side of the x axis rods. See how far off you are. You can also manually bring the nozzle down close the bed and jog the x-axis from one side of the bed to the other to see how far off the z-axis is on each side of the bed. With the printer off, you can manually turn one of the z-axis lead screws to move the x-axis rods so that they are orthogonal to the printer frame, or the bed whichever you choose to measure from. When you are finished the x-axis rods should be the same distance from the top of the frame, or the nozzle should be the same distance from the bed when the nozzle is jogged to the left, or to the right. That should get you in the right ballpark.