Built Delta reprap, but unable to get it working

Hi,

i built my own Delta bot, based on a kossel design, but i am not able to get it print "right"
i stiffened the frame, removed backslash as far as possible from any moving part.
i configured it, followed a few howtos like [minow.blogspot.co.at] , leveled the printbed .......

now it slowly started to work and produced a print like in the attatchment.
the part should be a cube 20x20x20, but for some reason he puts the layers not exactly over each other, instead he is more likely to build the cube in an about 45° angle
So i tryed to boost the stepper current to the max
... now he prints louder ... but not better :/
now he prints the part again each layer not exactly over the other, but now he also seems to not move the nozzle up the right amount, now he prints the 4. layer directly "within" the 3. Layer, and the nozzle scrapes on the cooled plastic :/, this effect seems to stack up layer by layer, and at the 4th layer it is enough to crash with the 3. layer :/

but realy all i changed was the motor current :/

The first thing that you will need to do is set the stepper motor current correctly, and that requires the use of a multimeter. Too much current supposedly also causes missed micro-steps. Follow the directions for whatever stepper drivers you have, and try to get them as close as reasonably possible to each other. Using A4988's on my printer, I managed to get the three towers all between 0.41V and 0.43V after several iterations.....

okay i have ordered new drivers now, cause at the moment i am using 1,5 A max stepsticks for my 1,7A rated motors.
i thought it would not be a problem due to the fact that i am using a delta with bowden setup.

Edited 1 time(s). Last edit at 06/23/2014 12:35AM by mantus.

You might also want to look at calibrating steps per mm on each axis.

steps per mm seems to be finde
i calculated it with [calculator.josefprusa.cz]
and i also measured the distance the 3 axis move when i tell them to move 100mm, no problems detected

Edited 1 time(s). Last edit at 06/24/2014 10:20AM by mantus.

i tigthend the belts, changed my drivers, and set the current as good as possible.

but nothing got any better as you can see in the photos, the print ist "drifting" away from the Z colum.
it is also nearly exactly 20x20, but it is only 8mm high instead of 10mm :/ any further suggestions?

Hi have you checked that the drive shafts are not slipping, also couldbe your layer thickness settings in sli3er or your z axis is not right, try printing slower see what that does, everybody wants to print so fast , whats the rush do it once do it right ) hope it helps

Check your steps per mm in the firmware, all axis should be the same.

If those match, then unless your printer leans worse than the Tower of Pisa, you either do not have enough current, far too much current, or you have some loose pulleys.