Can't get print off of bed (lulzbot mini)

I have tried everything including the suggestions here to heat the bed to 50C and tap it. I even bought air spray to try and cool it down… nothing seems to work. :frowning: I feel like I’m tearing up the bed itself now trying to get this off. The bed now moves back and forth when I pull/push on the print.

I’ve only printed 3 things (2 of them were the rocktopus). I could get the knife under the rocktopus but with my own model (a character bust) it seems to be impossible. This is very frustrating.

What did you print with?

Can you attach a photo that still shows the skirt? Wondering if your nozzle was too close to the bed.

I was just tapping the model trying to loosen it and cracked the glass bed. I’ve had this thing less than 24 hours and it’s broken.

I’m going to return it with my print stuck to the bed.

I printed with 3mm ABS from IC3D.

Ugh, that sucks. So bizarre. I have black ABS by IC3D and it comes off just fine. What did your skirt look like? Was it a very, very flat, very wide line, almost translucent?

On my Mini I’ve had to add about 0.05mm additional Z-offset (in Cura) and on my TAZ6 it was 0.1mm off (adjusted through the control panel discussion saved to the printer).

Regardless, with your bed broken there’s nothing you can do now. While it is no consolation, I broke my bed wishing the first few weeks of having the Mini by accidentally knocking over a large Maglite flashlight. Landed on the front edge of the glass. iT-Works as replacements (rejects?) for about $50 but I bought a replacement directly from Lulzbot for twice that.

Good luck with everything…

Well… I guess its too late now. In the future, use a tool with a thin blade to get under the print. I like an artists knife (particularly number 2) or . Manually get the edge under the print, then slide the blade around the print. For stubborn prints, lightly tap the tool handle. Don’t pry up, that will contribute to the PEI lifting from the bed… slide the tool around the object.

A little IPA (isopropyl alcohol) around the edges can help to get the blade under the print.

I feel a bit crazy but I’m honestly thinking about buying another one. The print itself was amazing! It was soooo frustrating not being able to get that thing off the bed. :frowning:

How do you know about the offset before ruining the machine? Even the rocktopus was crazy hard to remove and violently popped off the bed in the end. I nearly cut myself with that knife!

I could model a small undercut on each model just for prying. That would be no problem but if you could see how hard I have to pry. It’s only a matter of time before I damage the bed again.

It is supposed to be calibrated before being shipped. I’ve had to adjust both of my machines, the TAZ 6 more than the Mini. When I printed the first Rocktopus on the TAZ 6 the skirt was so flat and stuck to the bed I questioned whether it was going to come off. So I immediately adjusted it via the control panel (added .2) the tried again. It was much better but almost too much. I’ve settled in .1 difference than what came from the factory.

For the Mini you set the z-offset in Cura. I have 0.05 on mine and when I measure my skirts they come out perfect, the height measures almost exactly. I will eventually write the change to firmware so that it stays with the machine.

Go for it, get another one!

I’m not sure what you mean by the “skirts”. I’m brand new to 3d printing so… :confused:

You need to add a z offset. Measure your skirt with calipers. If the skirt thickness isn’t equal to the first layer thickness in cuts, you need to add a z offset in machine settings. Fixed part removal for me.

The “skirt” is the outline extruded around the print at the very beginning. It is used to prime the extruder to ensure a steady flow of plastic by the time it starts to print the actual part. The height of the skirt should be the same as (or as close as possible to) the layer height you chose to print at.
skirt.jpg

OOoooh… that’s the skirt.

So I’m totally going to buy another Lulzbot. I keep looking at the rocktopus that I printed on high settings and it really is amazing. Next time, I’ll print that and measure the skirt.

I can tell you that my skirts were not printing well. The skirt wouldn’t start printing until about half way through the skirt print so I would get about half the skirt. I didn’t think about that as a possible issue until now.

@Tommy, 3D printing is as much and art as it is a science/mechanical process.

The science are aspects like materials (filaments), temperatures, nozzle size, speed, etc. These are all variables, which, as you can imagine, when you add them up, make for a butt-load (tech term) of permutations.

The art is HOW you deal with all of these variables.

There’s a bit of bootstrapping you need to go through in order to create a baseline, even with a printer as well calibrated as the Taz. From a solid baseline, you will be able to experiment and modify with greater accuracy and control.

Good baseline:

  1. Measurements
  • space between nozzle and bed (use the method described in the user manual)
  • width of filament (enter this in the slicer) EVERY FILAMENT IS DIFFERENT!
  • Confirm layer height matches what is entered in slicer by measuring the skirt
  1. Temperatures
  • Follow suggested temps for you filament choice. If things are not flowing, adjust by +/- 2 deg at a time.
  • let things stabilize before you hit “go”
  1. Speeds
  • Slower is better until you get familiar with your printer / filaments. 40 - 60 mms is reasonable
  1. OBSERVE!
  • Print small, simple models first (<30 min. prints). Watch them print ALL THE WAY THROUGH! yes, sit in front of your printer for a half hour and watch the whole process. Amazing what you will learn about the behavior of your setup.
  1. Use easy filaments first
  • PLA. Period.
  • once you nail that filament, move to ABS. Learn about temp. control. ABS is a pain on larger prints.
  • Other, so many others… PETG, TGLASE, Exotics, etc, etc.

*6. WATCH OUT FOR SOME EXOTICS!!

  • Glow in the dark, metal additive, carbon…THEY WILL SHRED YOUR BRASS NOZZLE. There are alternative nozzles if you print these often.

OK, so this is really just a quick primer.

Get back into printing. Don’t get frustrated. There’s a HUGE community here to help.

It’s OK if the skirt takes a moment to get going. The filament sometimes need to work it’s way into the nozzle due to oozing or similar. That’s part of why you print the skirt, it helps prime the printer. I use a modified start script that extrudes a little extra filament in the corner to help with that as well. It’s nice for those prints that are on the bigger side, so you can’t print a skirt. Don’t worry about that till you get everything else sorted though, messing with the start/end scripts should be considered an advanced topic.

I like to print tiny test pieces with new filament or any bed changes until I get things like the Z-offset dialed in. It makes it less likely I’ll get something really stuck to the bed. I also start a little high off the bed intentionally. I’d rather have it “air-print” for a test than dig into the bed. Then move things down a little at a time to get where I want to be.

For stuck prints, I find it helpful to tap the top a bit with the handle of the knife of a similar tool. Just a few light taps, you’re not trying to pound it off, just the vibration can help loosen it up a bit. I use a putty knife for most removal. It has a nice flexible metal blade that I sharpened a bit with a file. The idea is to get under the print without using a lot of force. Push down with the blade, then tap lightly on the handle. The impacts will help push it under the print. Once you get under it, just push and/or tap a little more to pop the print off. No need to pry, that can damage the bed. Once you get something under it, it doesn’t take much to separate the print.

Another option I would also consider somewhat advanced is a removable, flexible bed. Take the bed off, bend it under the print. Usually pops all but the most solidly attached stuff off without much effort.

Regarding the skirt, I think it worth noting a settings clarification that (if using Cura) it should match the setting for the “Initial Layer Height”. Most profiles in their default have the initial layer set to “0.425” and that is what the skirt should measure.

At times I’ve messed with the settings and overridden the Initial Layer Height value, setting it to “0” (which means make it the same as the model height chosen for the print) and initial layer width to 100%.

In those cases:

    1. The measured skirt should match the layer height


    1. Sometimes I’ve had to up the skirt line count to 2 because of the other issue described where the skirt doesn’t start printing right off the bat. Especially on smaller parts I usually start to get the skirt extruding by the second line. (when not using the default initial layer height there’s less plastic being extruded)

Thanks for all the advice guys. As a digital artist, I’m much more interested in building the models than making them print but it was such a cool experience to see models printing. I’ll probably purchase another mini in a month or two when I get into my new house. :nerd: