z-motor running too much - kossel 2020

Hi all,

I just built mechanically a Kossel 2020

Still have a few questions as the printer is nearly working but not really.

1-
x and y move 10mm when we see 10mm on the LCD screen
z moves 65mm instead of 2mm as shown on the LCD screen
Why is the z axis moving 32.5x more than it should? is the stepper motor defective?
I see that if I go in control-->motion--> zstep is 2500steps/mm and x and y are 85steps/mm

2- what position is the carriage supposed to be at when set to 0mm?

3- the limit switches don't stop the motors. When I do autohome, the carriage goes all the way to the limit switch, hits it and keeps hitting until it runs out of motion. It does not stop the stepper motors! I do see the red LED light up when I press on the limit switch, but nothing is stopped. I have them connected to the x+, y+, z+ connectors.

4- The same goes for the z-probe, the probe gets close to the board, the light is on, but it lights up brighter when the probe gets close to the bed, but again, the stepper motors are still going.

Those sound mostly like firmware configuration issues to me. I think the firmware is configured for a Cartesian printer instead of a delta. Tell us what electronics and firmware you are using, and someone with experience of that combination will probably be able to help you.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

85 steps/mm is unusual. You seem to have 17 tooth on the pulleys?
But z-steps on a delta have to be the same. (2500/85=29.xxxx) roughly the same ratio of what you found.

Can´t help you with your endstop problem, don´t know what hardware the Kossel delta 2020 has.

-Olaf

Thanks for the replies guys.

I noticed the firmware version shown on the LCD screen said Mendel. I have a Ramps 1.4 board and Arduino 2560 (coincidentally same number as the z steps per mm... suspicious...)

I've gone and uploaded the firmware found on the Kossel google drive, When it was done uploading, I saw the LCD screen said Kossel Mini, which is also not what I have as its a 2020.
The pin assignments seem wrong when I compare them with a Arduino Mega --> Ramps board. Now, it seems when I move on x,y axis, things are actually moving horizontally, and z is moving up and down...

I would need to upload the right version of firmware, with proper pin assignments to be able to run this again.

The stepper motors are Kossel Kit XYZ = 2.6kg/cm motors
The website says NEMA 17 stepper motors.

It seems the Ramps was loaded with the wrong firmware this whole time. I'm now able to move the head straight up, down, left right. And the limit switches are working as it stops the motors.

Only part that is still not working is the z-probe which didnt stop the motors when the head whent crashing into the board!

Edited 2 time(s). Last edit at 09/06/2015 03:13PM by djtrance2.