Kossel 2020 delta printer - auto Z probe tuning

Hi guys,

I'm nearly there. I'm using the Z probe to automatically measure distances to the heat bed. I find at the moment that G29 z-0.8 seems to get the nozzle passing the paper test at the center of the heat bed.

However, when I move to X = 60mm, the nozzle is a bit lifted off the bed, maybe 0.4mm above
Then I go to X = -30mm Y = 52mm, the nozzle is a bit down on the bed, at 0.1mm under
At X = -30mm Y = -52mm, the nozzle is again maybe 0.5mm above the bed.

What parameters would I need to play with to get this working?

There is a calibration procedure for deltas.
But depending on the firmware, you have other options to set the endstop positions (M666) or set rod lengths and delta radius ( M665 )
Then setting z-zero offset with M428.
IMHO it doesn´t make sense to use G29 before you haven´t dialed in the basic variables
-Olaf

Thanks for the link. This is very good procedure. However, there is one part that seems a bit difficult:
1- it seems we need to adjust for the tower endstops manually using the screws that fasten the endstops to the extrusion aluminium. I can see 0.3mm adjustments to be very difficult to do by hand, are there setinngs in the firmware to adjust those distances instead?

Quote
djtrance2
Thanks for the link. This is very good procedure. However, there is one part that seems a bit difficult:
1- it seems we need to adjust for the tower endstops manually using the screws that fasten the endstops to the extrusion aluminium. I can see 0.3mm adjustments to be very difficult to do by hand, are there setinngs in the firmware to adjust those distances instead?

You can use "M666" to adjust the endstops.

[www.youtube.com]

Thanks so much! best video ever!!!!! (for this purpose)

In this video, the Gcode command used is M665.

I am using the Kossel Mini firmware.
These commands (M665 and M666) don't seem to be in the command list in the MarlinMain.cpp. Any way I can add them or use other commands? Or perhaps use another firmware.

I've tried using that command as M665 z200 instead of the default 315mm that the head is over the print surface. I follow with m500 tosave the command in EEPROM. When doing g28, it seems to reset the zmax to 315mm. I dont feel the M665 command is affecting the calibration at all. Is there something I am doing wrong?

Should I be using M666 instead?

Edited 1 time(s). Last edit at 09/20/2015 11:56AM by djtrance2.

Quote
djtrance2
In this video, the Gcode command used is M665.

I am using the Kossel Mini firmware.
These commands (M665 and M666) don't seem to be in the command list in the MarlinMain.cpp. Any way I can add them or use other commands? Or perhaps use another firmware.

I've tried using that command as M665 z200 instead of the default 315mm that the head is over the print surface. I follow with m500 tosave the command in EEPROM. When doing g28, it seems to reset the zmax to 315mm. I dont feel the M665 command is affecting the calibration at all. Is there something I am doing wrong?

Should I be using M666 instead?

The Folger firmware is based on an older version that they added the autoprob routines into, hence no M665.

Grab the Release Branch from [github.com] and carefully merge in the Folger Configuration.h and Configuration_adv.h values to the newer release.

Rick

Thanks,

I did just that, merged the defines that were from the old version into the new code.

G28 takes us to the right place.
then M665 z300 and M500, and G28. I still get z315. I think it should be showing 300 at this point.

I saw in the code that M665 sets a few parameters, but it does not include Zmax.

I added some code in M665
case 665: // M665 set delta configurations L R S
if(code_seen('L')) {
delta_diagonal_rod= code_value();
}
if(code_seen('R')) {
delta_radius= code_value();
}

if (code_seen('Z')) {// set the maxZ
ZMaxPos = code_value();
}

However, this still does not show the right values when I do g28 and check M666 L, I get Z (Height) is still 315 instead of the 300 I set.
I can see however that before the G28, the Z(height) was indeed 300. The M500 probably recorded it but didnt load it right, or vice versa.

Additionally, the UI on the LCD doesn't show anything.

Edited 1 time(s). Last edit at 09/21/2015 03:27AM by djtrance2.

I noticed thathe code I was adding actually does the same thing as m666 h300 for example as that sets the max_pos[Z_AXIS] so I will just be using m666.

After saving M500, and g28, M666 L displays the values and shows that the M666 H300 call actually did its job.