ABS doesn't stick anymore !?

[KFix]

Hi printrbot owners !

I would like to have some opinions about my experience on printing ABS on PrintrBot Simple metal with X-Axis and HeatedBed upgrade.

So last week I received my first ABS spools (From OPtimus ABS). And i have to say that I was impressed by the stickiness of the first layer on my kapton sheet at 100°C.

That, was at the beginning…

I let the spool on the printrbot for a few days, and then now, no matter what I can’t get a proper first layer.

Each time the filament is extruded, it simply doesn’t stick to the kapton. After a few cm movement the ABS sticks, but each time there’s a retraction, the starting point of the extrusion

doesn’t stick.

As absolutly no parameters changed in the weekend, I thought it would be related to the humidity. It was rainy, even if I didn’t let the windows open maybe it has affected my filament ?

My second spool was in a box (unsealed) and I have the same problem…maybe slightly less important.

Is ABS as sensitive to humidity as that ?

I work with PLA the same way for over a year now, and I had no such problems.

I bought plastic sealing bags, put my 2 spools in, along with big silica gel bags, and I’ll try it again in 2-3 days.

Thanks for sharing !

[ProtoPrynt]

Keep your ABS dry!!! Always remove from the printer and put in your bags or containers immediately after use. Otherwise you will get steam bubbles in your prints…

now for for that adhesion issue, have you cleaned your kapton tape after touching it? The tiniest amount of finger grease will ruin your adhesion, use acetone or rubbing alcohol to clean your tape between prints. Also I do not like to use this as it usually causes too much adhesion but as a last resort melt some abs in acetone and paint your cold bed with a very thin layer and allow to dry before heating your bed

[KFix]

Thanks !

I rubbed my kapton sheet with alcohol when bed was cold, and the first layer is sticky again

However it seems I have some infill overlap problem, still on the first layer (unwanted gaps when I try to print extruded numbers for example).

Here are my settings :

Hotend : 240°C constant

Bed : 105°C for first layer - 100°C for 2nd - 90°C for others

Overlap : 15%

First layer width : 140%

Thanky you

[MonkeyRobot22]

Another thing not addressed here . . . very often if you are not adhering your first layer it’s because the bed is too far away from the extruder. On the first layer you should get a nice, even “squishy” layer that is just flattened by the space between the extruder and bed. You should always re-level the bed if you are getting these kinds of issues. If you are still just too far away and your bed is not heated, you can add an extra layer of tape to get the bed just that much closer and get ideal “squish”.