Stuck to the Bed

I have a big problem removing printed objects from the print bed. Currently I am using IC3D red ABS. Even after an overnight cooling the object is very difficult to remove. I have damaged objects trying to pry them up with the blade included with the printer.

Any tips for this beginner?

Dave Matthews
KI4PSR

Try increasing the Z-offset. It’s in the machine settings in cura. Try 0.2 to start with. That will move the start of the print up 0.2mm. You can also try removing the print when the bed is at about 50C. Letting it cool all the way is probably not a good idea. There’s even some gcode scripts around the forum to hold the temp for a set amount of time, to make sure you don’t have to be right there when the job is finished.

I’ve had good luck using freeze spray on some prints, but I mostly did that on my Flashforge Creator, which has an aluminum bed. I’d be very careful trying it on a glass bed. I have done it, but am careful to just get the spray on the part, and not on the bed. I would be concerned about cracking the glass.

If you spray the parts lightly around the perimeter, the print will contract and pull itself free. Sometimes.

Lulzbot also recommeds removing parts while the bed is warm. For PLA, 50C works well. The parts actually stick harder at room temperature.

In addition to the suggestions above, get a good tool with a wide blade which can get under the print. I like the #4 paint knife in this set: http://www.amazon.com/eBoot-Stainless-Palette-Painting-Spatula/dp/B01ANL61FS/ref=lp_12897951_1_14?s=arts-crafts&ie=UTF8&qid=1464143446&sr=1-14
The angle before the blade provides good leverage for getting the blade under the print. Once the blade is under the print, just work it around the print until it pops off.

Try not to pry up, it will increase the chances of the PEI lifting off the glass.

  1. ABS parts are to be removed at 50C. Do not let the part cool down and heat the bed back up unless you have to. The part removes easiest right when the bed moves forward.

  2. Under the cura Advanced tab, reduce initial layer line width to 100% instead of 125%

  3. Under Machine: Machine settings, add some Z offset. The best way I’ve found to check this is look under the advanced tab, your initial layer thickness should be 0.425 or thereabouts. Make a small print and remove the skirt that is first printed. Use calipers to measure the thickness of the skirt. If the thickness is under 0.425, add the different to the Z offset and print again. You won’t get perfect, but it will improve things.

Example: If you skirt measures .4mm, add (.425-.4) = .025mm to your z offset.

For reference, my mini requires an offset of .18mm. Parts stick to the bed well but come off pretty easily depending on the surface area stuck to the bed.

Another tip is you can use the blue handle end of your removal knife to tap on the part. If the part is taller, it can help loosen the adhesion at the base if you tap near the top.

-Jim

Thanks for the reply, I will try that.

Interesting! I will find some freeze spray and give that a shot. Thanks!

Good advice, the little blue knife is way too short to keep flat against the bed for most of my attempts so far. I will get a better tool, thanks for the reply.

Thanks for your detailed response, I have printed it out!


That did the trick! I added 0.15 following Jim’s instructions.
Thanks

Thanks Jim that did the trick! The skirt I measured looked to average about 0.31mm. I wound up adding 0.15 to the Z offset and the prints easily pop off of the bed. I appreciate you help, and also those others who responded.

Dave



I concur with the z-offset setting. My experience with what I called “adhesion nightmares” led me to conclude that spacing was critical. While not as quantitative, I found that ABS had have a larger gap and not squeezed into the bed or you would never get it off. PLA the opposite; it had to be closer or it would lose adhesion mid-print, slide around and you’d get spaghetti.

Glad it worked out for you! I had quite the time removing ABS from the bed before I found the Z-offset. Also always remember to remove your ABS/HIPS prints at 50C bed temp to prolong your PEI surface life!

Keep Extruding!
Jim