Removal of PLA if glass is permanently fixed to printer

Greetings,

I have a question regarding use of PLA. I mostly use ABS, for its higher thermal tolerance, but do use PLA some too. I use ABS juice to get good adhestion, and have no trouble getting ABS to release once the glass above the heated bed cools. When using PLA, I use the purple gluestick for adhesion and this works well. But to get the print to release, I remove the glass and set it in the sink in a shallow pool of water to solubilize the glue. So, to the question… I have read where some use thermal compound between the heatbed and glass. This would seem to make the glass a permanent part of the heat bed. In this case, what is the best way to remove PLA prints without having to separate the glass from the heated bed.

Thanks,
David

Simply dont use any glue at all, just make sure the surface is clean and the nozzle very close to the surface, i calibrate with the thickness of 4 layers of aluminium foil

Works like a charm for me every time, the print almost snaps off by itself when it has cooled down completely

Many thanks, Tides. I will certainly try the clean glass approach.

David

I use hair spray and mounted a fan 80mm on the frame.
When the print is done the bed moves to that position and I turn the fan on to cool the bed faster and it pops off on it’s own.

Thanks for the tip, WrongWay! I may give that a try too. I have several old 92mm case fans scavenged from PCs that would be easy to mount to the frame. For PLA use only, I suppose. I like to let ABS cool slowly.

David

I should also mention that I use a separate power supply for the fan.

Thanks. Actually, I run off of three power supplies; the 15V one that came came with the printer, a 24V/15A PS for the heat bed (controlled by a reprap power expander), and a separate Meanwell 100W 12V PS for the E3D-V6 fan and some LED lighting. The 12V PS should have plenty to spare for another fan.

I’m still not pleased with the non-uniformity of the heatbed (but at least getting to 110C for ABS is no longer an issue. I might try a 3mm aluminum plate between the HB and glass for more even heat distribution, though I’m not sure how to get accurate temps with the NTC with that mod.

[quote=“dwmccaul”]Thanks. Actually, I run off of three power supplies; the 15V one that came came with the printer, a 24V/15A PS for the heat bed (controlled by a reprap power expander), and a separate Meanwell 100W 12V PS for the E3D-V6 fan and some LED lighting. The 12V PS should have plenty to spare for another fan.

I’m still not pleased with the non-uniformity of the heatbed (but at least getting to 110C for ABS is no longer an issue. I might try a 3mm aluminum plate between the HB and glass for more even heat distribution, though I’m not sure how to get accurate temps with the NTC with that mod.[/quote]

Consider putting thermal compound between glass and heatbed PCB. Thet helps a lot.

cheers,

Christian

Thanks Christian,

Your suggestion is actually the genesis of this thread. I was wondering how to remove PLA if the glass is permanently fixed to the PCB, since I have been using the purple gluestick for PLA adhesion. I tried WrongWay’s suggestion last night of just using clean glass and it worked nicely, provided that first layer was strong. So, I do now plan to place thermal compound between the HB and glass. Any suggestions on the “best” one to use? I have a small tube of Arctic Silver 5 (though not sure it’s enough for 400cm2).

David

[quote=“dwmccaul”]Thanks Christian,

Your suggestion is actually the genesis of this thread. I was wondering how to remove PLA if the glass is permanently fixed to the PCB, since I have been using the purple gluestick for PLA adhesion. I tried WrongWay’s suggestion last night of just using clean glass and it worked nicely, provided that first layer was strong. So, I do now plan to place thermal compound between the HB and glass. Any suggestions on the “best” one to use? I have a small tube of Arctic Silver 5 (though not sure it’s enough for 400cm2).

David[/quote]

The cheapest type will do, i think.
It should only make the heat distribute more evenly.
I used a no name brand that came in tubes of 20g i think. Cost me about 8€ for 2.

cheers,

Christian

Hi ,
I’m told that using freeze spray around the base of the model after its printed causes it to momentarily shrink enough that it just pops of by itself.
Neil.

Hey all.

I have the PCB mounted track side up with layers of cardboard underneath for insulation.
Also, thermal tape/thermal compound between PCB and glass.
I use diluted PVA on the glass for added insurance against the PLA lifting off the bed.
After the bed cools the print lifts off effortlessly.

Something I’ll try soon is to use thermal tape only on the PCB and put a layer of aluminium foil over the thermal tape.
This will allow easy removal of the glass - glass off/glass on for the next print (allowing time for the fresh glass to soak up some heat of course).