Best practices to remove finished prints from print bed

Hi folks,

I am a newbie at printing and own a TAZ 5. So far my experience with it was great, but I sometimes have troubles getting my 3D prints off the print bed once the print is finished. I am printing HIPS at 240 (hot end) and 110 (print bed) so when it is finished I let the bed cool down to about 50 degrees before I try to get the print off the printer bed. So I was wondering if there were any good tips for retrieving my finished prints without destroying them or the PEI surface with the clam knife. Should I wait until the printer bed is completely cooled off? I wonder what the PROs say :slight_smile:

If the prints are still really hard to get off when the bed is at 50 degrees, I suspect your first layer is a little to smooshed. Try adjusting the Z-stop up a hair and try again.

Also I don’t use the knife that came with the TAZ, I use a utility knife blade. Not the knife, just the blade. You just need to get one edge to separate a hair and the print will pop off. The utility blade seems to do that much easier then the knife.

Thanks!
Steven

I don’t use the knife either… I had a stainless steel mixing spatula that has a little flex.

Regardless, that worst thing to do is pry. Meaning once you get under the edge of the print, don’t pull up or lever the handle. It’ll gouge or leave a mark. Instead, continue to slide the blade under the print… you may need to wiggle the blade side to side. You’ll eventually get far enough under the part and it’ll pop off.

Also agree that if your print is so well stuck on the PEI, an eighth turn on the Z-endstop would help. I’m also using the Z-offset fine-tune adhesion after setting the endstop. Usually .1-.2 helps once I can get a business card (with some friction) between the nozzle and bed.

Get yourself a painters knife (also called spatula) at an art store. Best product ever for removing prints.
Spatula.jpg

I recently had a part that was about 3" X 4" and a half inch thick, stuck to the PEI covered bed. Big surface area with too much adhesion on the first layer (HIPS profile). I tried the clam knife, but it would’ve destroyed the PEI, it was that stuck. I eventually used a 3/4" wide wood chisel and something to tap on the end of it. I put the tapered side of the chisel blade against the bed under the edge of the part, and tapped gently. After a number of Tapps it popped off the bed about 4" into the air. No damage to the PEI…

Mark -

I feel like a 110 bed temp is kind of nuts for HIPS - I honestly haven’t done too much printing with it, but I usually have my bed set at 85 (or even 55) for HIPS.

Thanks for all the insights! I will also do some tests in lowering the print bed temperature as outlined in the advice posted but I never had any problems with discoloration (longest print was 14 hours so far) so I figured that I’d stick with the setting the printer shipped with. There is a ton to learn :slight_smile:

Wow, 55 to 85 are like PLA bed temps aren’t they? I’ve been printing HIPS at 110C because that’s what’s recommended for my TAZ 5 with a PEI bed. If I understand correctly the characteristics of HIPS are very similar to ABS. :confused:

Mark -

Ah gotcha - I don’t have the PEI bed, so yeah they’re probably different. My bad!

100-110C are the recommendations from Lulzbot for the PEI bed.

In general 85C should keep ABS adhered pretty well to PEI. 100-110C for the entirety of the project could cause discoloration of light colored ABS. I think at 100C, the ABS is still malleable which could lead to warping or delamination.

If your slicing software supports multi-temps for the bed, start with 100C+ for the first few layers then drop to 80-85C… best to gradually cool the bed down. I think 70C is actually a good temp after the print reaches 20mm at which point the bottom layers shouldn’t be affected by the top layers.

I’ve only run HIPS on my Kittaz. I started out with the Buda and PET. For that combo, 230c for the nozzle and 110 for the bed gave me pretty good results, but I would have heat buildup on the lower layers causing serious distortion. This weekend, I installed the Hexagon hotend, and switched to a .010 sheet of PEI. I’ve found that with this combo, 240c for the nozzle, and 85c for the bed is working really well. I am currently printing the part I had distortion problems with the old setup. I’ll see how it turns out. I am 4 hrs into a 9hr print.

So far, the other prints I have done have been real easy to remove once the bed drops below 50c.

Scott

I tried that strategy for my latest HIPS print. Started off with 110 and then set it to 85 but when I came back to check after a few hours I was greeted by the unholy spaghetti monster instead of seeing the progress I expected. The bottom disconnected from the print bed and my dear printer printed for 1.5 hours into the air producing a nice plastic tumbleweed. So I’ve restarted the print and won’t touch the temp for the bed for now :smiley:

Uh… sorry. It works well for me with ABS. I usually start at 105C, then drop to 100C at the 1mm (layers would vary depending layer height), then after 50mm drop to 80C.

If you want to try again, maybe lower your endstop a tad to increase adhesion. I like the Z-offset option in slicing software for tweaking. My Z-endstop is set so that a small print adheres pretty well, and I’ll use .1 on the offset for larger objects which I know will stick too well.

Ah that is a good idea, yeah I haven’t played too much with my Z-endstop yet cause I thought I had it in a good spot after calibrating it the first time with the screw. I didn’t know that there is more on the software side to fine tune it - got to play around with that some more. Thanks for the insight!