Can;t get ABS to stick to heated bed

[awander]

I am using an aluminum sheet bed heated to anywhere between 180-240 degrees F. The ABS won;t stick to it.

What should I check?

Andy

[guanu]

I found the best way to get prints to stick to a heated bed is by covering the bed with polymide tape (kapton tape)... then the prints stick so well I have to wait for the bed to cool to remove them.

Guanu

[awander]

Hi Guanu:

I forgot to mention, mine is covered with Kapton tape.

What temp do you use on the bed?

[guanu]

i have the glass around 210 F as tested from the top of the bed... I just need to replace the glass.. ( I had a glass company cut me a 7/7.5" sheet of 1/4" glass..) it cracked the other day, but still works since its just one diagonal crack and the tape holds it together...

Guanu

[michaellatif]

I use Kapton tape and run the bed (surface) at ~110-120C. Once in a while (every 2-3 prints) I will wipe the Kapton tape down with rubbing alcohol when it is warm. The prints stick so well that like Guanu, I have to wait till the bed cools to free the prints.

One other thing to keep in mind is that the first layer needs to be squished to the surface, this also helps the print stick. I use the business card trick (the card should be able to pass/catch a little when run through the gap of the nozzle/bed) that John uses to set the height of the Z axis.

[awander]

I'm not familiar with John's business card trick. But I set the Z height using a height-setting routine that lowers the Z axis until it hits a grounded metal plate, then sets Z to the value of the plate thickness.

So I am reasonably sure when I say Z=0, the nozzle will touch the bed.

Should I be doing it some other way?

[Dave_Sohlstrom]

I am having the same problem Andy is. I am trying to print a part that is 2.5X4.75x1" . My first layer squish is good and seems to stick well but by the time I am 2 to 3mm high the corners are starting to lift off. The table is running at around 100C with Kapton tape. I am starting to think that my hot end is running to hot so I am getting a lot of shrink in the ABS. I am going to dial back the temp on the next print and see what I get.

[Polygonhell]

How old is the Kapton, the first thing I try when I start to get peeling corners is to replace the Kapton (which I thoroughly hate doing), it seems to wear out very quickly. I've been told that PET tape is better if your printing ABS as much because it's more resilient and sticks better.
The other thing you can try with ABS is to wipe down the Kapton with Acetone before the print.
If that doesn't work there is always ABS juice, dissolve a small mount of filament in some acetone and wipe it on the bed.
If all else fails use Skeinforge and print a raft.

[Dave_Sohlstrom]

After reading the replies here I tryed the ABS and acetone mix. I made my mix fairly thick and used a paint brush to put down a layer on a hot table. I've been printing now for 3 hrs I'm18.5mm high out of 25 and not lift at the corners. Do not know how hard it is going to be to get it off the table. I expect the tape will come off with the part.
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