Prints Impossible to Remove

Hi everyone,

I have been following this forum for some time now and I thought I may as well post because I am actually having an issue which I think you could help with.

I have a generic (locally made) i3 printer with an aluminium heated bed. I have managed to fine tune the printer to achieve beautifully smooth prints along with almost perfect first layers however my issue is more with the fact that once the prints are done, they are almost impossible to remove from the bed without damaging either the bed or the print itself. I have printed with a raft and I can remove the print fine but the raft then sticks too much.
This occurs with both PLA (Hotend: 210deg; Bed: 65deg) and ABS (Hotend: 230deg; Bed: 105deg). The prints are difficult to remove regardless of the temperature of the bed. I have left prints to cool overnight, I have tried removing them right away and I have tried removing them when the bed is at around 60deg for ABS and 40deg for PLA. No luck. I eventually have to resort to either brute force or using a razor blade to get under the print and try lever it off the bed. This works sometimes for the smaller prints but no luck for the larger prints. I have also damaged my bed due to this.

The upside to this issue is that I get perfect adhesion! I am currently printing on a super-thin layer of ABS juice which has been evenly sprayed over the heatbed. Oddly enough, I also print PLA directly onto this juice and it sticks wonderfully. The reason that I don't use Blue Tape is that due to this sticking issue, the tape sticks to the parts and cannot be removed. The other day I resorted to printing PLA on Kaptom Tape just to make the part a little easier to remove as I did not want to damage it due to fragility issues.

Its great that my prints are sticking so well but they are sticking TOO well. Could this be due to the fact that I keep the heatbed just above the glass transition temperature?
I use an inductive probe for my bed leveling and am thinking of purchasing a PEI Sheet but am afraid that the probe wont activate with the sheet on; am I wrong here?
I use Simplify3D as a slicer.

Thanks all!

Nice problem to have. There are lots of ways you can reduce adhesion; reduce the extruder temperature for the first layer, print the first layer faster, increase the z0 height, reduce the first layer width, partly cover the print surface with a tape that doesn't adhere well to the first layer.

Don't put too much hope in PEI. I've swapped it with PrintBite because of too much adhesion (broke a chip from the PEI sheet when removing a part). Printbite is perfect for ABS. Good adhesion when hot, part pops when cooled. PLA is so so, PET-G so-so in removability

Edited 1 time(s). Last edit at 03/01/2017 05:05PM by sigxcpu.

Thanks for the replies!

I realised that one of my major issues was probably a stupid mistake that I did without thinking. Before almost each ABS print, I sprayed MORE ABS juice which led to layer upon layer being deposited onto the plate leading to basically one massive brim. I am cleaning off my plate now and will try again later once it is clean, will keep you all updated