Geeetech

Printer is Acrylic Prusia I3.
ABS plastic.
Default setting in RepetierGEEEtech 0_90D_2, .2mm, 19x15, ABS 1.75mm.
Printed at 260-265C, bed - 110C.

240 degrees for extruder and 95 degree for bed are enough for ABS.
I think you'd better tighten the x belt a bit, not too much.
You'd better give me your slicer settings, give me some pictures, I think your slicer settings are not so good.
Please tell me your nozzle diameter.

I think 240C for my plastic is not enough - small pellets formed and layers do not adhere good.

Nozzle: 0.3
Filament diameter 1.75, multiplier 0.6
Temperature first layer: 255, other: 250, bed 120.

You can try with my setting. Now that you think 260 degrees is better, then you can keep 250 degrees.
And from the first layer you print, I think you can lower the distance between hotend and hot bed to about 0.2mm.
Sorry, we have to keep approval system, because there will be more spams, which will spend us more them replying people who really need help. Please understand. When we are on duty, we will approval system once per minute, and we will reply you as fast as possible, unless the problem is really hard to solve that we have to assemble our technique support to get a best solution.

My setting is based on your setting except speed (my lower) and temperature.

There is 1 sheet of paper between hotend and hot bed .

Why did this happen?

Could you please send me your stl files? I want to find out the problem with my experience. Thank you.

Attached.

Now I am printing with stl file, I think I should also print with g-code file with your settings. Please send me the g-code files.

This is the model I print. I think you'd better smear a layer of glue on hot bed.

I print with 240 degrees for extruder and 95 degrees for hotbed.