Having some weird issues over here...

Hi, I'm trying to properly set up a 3D printer, and... well, you can see the results of a bullseye callibration by itself. There was even MORE excess material on the perimeter, but I had to remove that one so it wouldn't get burnt with the noozle.

This is a Geeetech G2S pro, and I'm pretty sure I messed up big time somewhere, because only the center is somewhere near enough to the noozle for it to actually stick to the base. The rest is a mess, I've seen most of the perimeter be like 5 mm away from the base.

It's like that 16 point grid calibration before each print calculates where the base is wrong, and the result is it thinks the base is like a bowl when it's actually flat? I need some help, I'm quite lost on this... I even tried changing some lines in the firmware that deal with concave/convex base calculations...

Anyone has any help? It'd be very appreciated.

Didn't the printer came with the firmware already set? Did you modify something in the printer? Can you be more specific about the bullseye calibration and what did you change in the firmware?

Usually is the other way around, the firmware assume a flat surface when in reality you have a bowed bed.

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ggherbaz
Didn't the printer came with the firmware already set? Did you modify something in the printer? Can you be more specific about the bullseye calibration and what did you change in the firmware?

Usually is the other way around, the firmware assume a flat surface when in reality you have a bowed bed.

This printer was a "build it yourself" kind of printer, and there were instructions about modifying that part of the firmware (it was changing just one number to make it concave or convex). The concave-convex part doesn't seem to do much though, as the problem seems to stay even if I change it or not.
the bullseye calibration is a model I downloaded to identify the problem easily (Not provided by the printer, found it on my own). On small centered prints, the surface can stick easily, but on bigger ones, the sides simply don't touch the base.
And the printer does the 16 point calibration before each print, using the probe (Has nothing to do with the bullseye callibration, just to make sure), maybe that could have something to do with it?

Oh, forgot to mention, this uses 3 motors, instead of the usual X and Y. This is the model [www.geeetech.com]

Edited 1 time(s). Last edit at 10/11/2016 04:16AM by Printston.

Have a look in the delta printer section.
Bed alignment is more complex than XY machines as it involves having the correct arm lengths and tower positions. You will find similar issues there.

Looks like it is a bed adhesion issue, because nozzle is dragging the filament.

Try some glue on the bed. a simple "paper glue" will do, like scotch glue stick.

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Veesta
Looks like it is a bed adhesion issue, because nozzle is dragging the filament.

Try some glue on the bed. a simple "paper glue" will do, like scotch glue stick.

8076126_1200x1200.jpg

Oh that is not the issue, I already used some nice sticky stuff and it does wonders (before that, it was EVEN worse)... However, the sides are simply too far from the ground to even touch it. I'll have a look at MCcarman's suggestion, delta alligment seems to be the problem in my case, since it's what the instructions seemed to ask me to tweak before.

Thanks for the help!

Hrmm, that's an interesting design. There are no vertical supports, looks like they rely on the smooth rod. I wouldn't think that'd be rigid.

Either way, things to check:

1. Those vertical rods are 90 degrees to the bed. Center of bed, base of smooth rod, some distance up the smooth rod would be your triangle points

2. Hopefully none of your towers are rotated. Take the tower closest to you, measure from the base of the smooth rod on the right to the base of it's closest smooth rod the tower to the right, then do the same with the left rod. Do the same for all the towers. They should be equal, or at least really close. You'll do the same thing for the top. If not, something may be off with the build, companies have been known to put holes in the wrong places in acrylic parts.

3. Measure that your arms are all equally long. Measured from the the center of the balls in the ends. Those being different than each other will cause a problem. This is also your DELTA_DIAGONAL_ROD length, this should be the value in your firmware.

4. Make sure the tubes from the extruders aren't pulling on the effector as it reaches the edge of the bed. They may be preventing it from going down.

5. Make sure the distance between the balls at the effector are equal, and then make sure the distance between the balls at the carriages are equal to that.

6. If you're confident the hardware is good, some things can be calibrated out in software. DC42's Delta Calculator will help. http://escher3d.com/pages/wizards/wizarddelta.php

Edited 1 time(s). Last edit at 10/12/2016 11:32AM by FA-MAS.