Things aren't sticking!

Hi All,

I've been printing with my mendel for a few weeks now. I recently developed a heated build platform. I'm using a 120V heater pad connected to a solid aluminium build surface all controlled by a thermocouple and pid.

I have been printing using the Silver PLA plastic from Ultimachine. The issue I'm having is that I can't get the material to stick and in all cases experience warping on large parts.

I have tried kapton, aluminium, masking tape all at room temperature and temperatures up to 150 degrees C. But it just wont stick!

Any advice regarding my problem would be greatly appreciated.

- makerswamp

Try glass at 150C. It works well for natural PLA.

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[www.hydraraptor.blogspot.com]

Also try try cleaning the build platform with rubbing alcohol between prints.

I dont know if the colour of PLA is important, but I have used red, kawasaki green and blue, and they all stick like sh1t to a blanket to kopton brand polyimide tape with a heated bed. Im not sure exactly the temp, but I think im using around 65 deg. I can touch it for a while without burning my fingers. I'm heating my techzone bed (thin alu plate) with a travel iron which fits nicely under the build platform with a couple of printed supports.

Makerswamp, is your Z calibrated correctly? I use PLA as well on a heated bed with no issues at all... I do use blue painters tape though.. Maybe try that? I can say when my z was not close enough I had problems....

Question for you.... I too am using a 120v heating pad / thermocouple on a 5 mill cast bed,, how are you controlling your heater?
If its through software can you send me your firmware? I am using a thermocouple for the extruder and want to use another to control the bed through the extruder and am having some "frustrations" with the coding.....
Right now I have to manually turn the bed on and off......

Edited 1 time(s). Last edit at 10/07/2010 10:57AM by DanielG.

I'm using a PID and thermocouple switched with a solid state relay. That way, my arduino can only worry about motor control and not heating the bed.

Nophead. Thanks for the advice about glass, I tried to print PLA onto a 4x6 inch piece of glass from a photo frame, however again, it didn't stick. I set my bed to 150 degrees c. Would you recommend wiping the surface with isopropyl or something?

I'll keep trying tonight, but I did order some black ABS from makerbot and am keen to get some PET from mcmastercarr

[www.mcmaster.com]

Nophead, your feedback on the above link would be greatly appreciated.

-makerswamp

If the surface is greasy then isopropyl will make it stick better. Here is my work on PLA on glass [hydraraptor.blogspot.com] and here on copper [hydraraptor.blogspot.com].

I have some black ABS that doesn't stick to kapton so maybe sliver PLA doesn't stick to anything. Has anybody used it?

The PET tape doesn't look high enough temperature rating for ABS.

Edited 1 time(s). Last edit at 10/07/2010 04:32PM by nophead.

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[www.hydraraptor.blogspot.com]

I've had good results (so far) with 4042D natural PLA on dibond fr + 1mm aluminium + PET tape, and no heated bed.
Wash down the tape with some alcohol, heat it a bit with a heat gun (hairdryer?), start the print with the head low to squish the filament a bit, then continue to heat sparingly during the first layer to make sure you get a good adhesion.
I use this cheap PET tape: [www.dealextreme.com] ( wider version available, but I haven't tried it: [www.dealextreme.com] )

I used lightly sanded kapton directly on the dibond before, but larger parts warped even if I used the heat gun.

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-Nudel
Blog with RepRap Comic

The silver sticks fine here, but I print on blue painters tape and don't use a heated bed.

Ok. I found a way around this.

I'm using PET on a heated bed at around 80 degrees c. Before each build, I wipe down the surface with acetone. Prints now seems to stick pretty well.

My new problem is OOZing with the silver PLA. My prints get very messy when starting and stopping the extruder. (But that's a question for another post on the forum!)

Thanks for all the help,

-Makerswamp