Improving ABS adhesion on hotbed

[stienman]

I finally installed the heated bed, then put glass on top with kapton tape on the glass. Unfortunately ABS is still having a hard time adhering.

I'm running the extruder at 230C, and the bed at temperatures from 70C to 110C (ive tried several configurations, assuming that theres a magic temperature...) and I'm finding that the first layer isn't sticking as well as I need it to for some prints. The calibration cubes are fine, for instance, but when I print a snake it tries to print several smaller unconnected features, and the little pieces start sliding all around as the head attempts to print near them or on the next layer above them.

If the first layer is one unbroken line, or bounded by an unbroken line then things seem to go better. I'm using slic3r right now, would a different slicer generate a more suitable path that will better secure the first layer? I'd like to keep using Keaton on glass, but should I be looking at other bed materials instead?

This is for ABS. I have some PLA, but I'd have to switch over to the 1.75 nozzle, and while it's not particularly hard to change the filament dismeter on this machine I'd like to be able to run ABS easily in the long run anyway.

[Racer]

I use 3M Scoth-Blue #2090 and it is working good for me. I have tried all other 3m numbers and this is the only one that works. The only trouble I have is removing the print.

[xojins]

I was having the same issue. I ended up putting my scrap abs test pieces in a glass bell jar and added some acetone to dissolve the abs. Use a paint brush and paint the abs goo onto the bed when it's cold.

The abs sticks really well to it when it's heated up. Just have to let it cool down and use a razor to remove it.

[steveeverson]

Im using a heated aluminium bed with a layer of Kapton tape which works well. Best results so far are when I clean the Kapton with some tissue dipped in Nail polish remover first. (has acetone in it and is cheap and easy to get hold of)
Im running the Bed at about 80deg C and the Hot end about 220 deg C using black ABS filament.
Cheers
Steve

[stienman]

Thanks for the tips!

I cleaned it with alcohol (50%) and used a thermocouple to check the bed and extruder temps, and found the bed was ok, but the extruder was off by over 25C at the high end. So I'll need to fiddle with the calibration tables in the firmware, but for now I extrude at 250C for ABS, which actually ends up being between 200 and 210.

With clean kapton and correct temperatures the prints are sticking very well.

[johnoly99]

I was just getting ready to say steinman, check your temps. The thermistors tend to "creep" it seems from when they're new till after a few hours. First installed, I get them dialed in, then after a while I recheck and recalibrate, and they seem to be good to go then. I thinnk it's prob more to do with heat cycles in the wiring than the thermsitors.