Sensorless Homing on a CoreXY

djstephenson1

Howdy all,

I hope y'all are doing better than my beloved Texas is fairing in this pandemic.

I am writing because I have just setup my Duet 2 Wifi to run latest version of RRF3 on my Two Trees Sapphire CoreXY. I am having some interesting issues with the homing.

First off, I want to use sensorless, because I like to use stall detection. The trouble I am having is that, I have never set up a CoreXY before, and I really cannot find much documentation regarding the Duet's sensorless homing and CoreXY.

I understand that the longer belts means that it is more difficult for the drivers to interpret stalls, but surely, sensorless homing can at least work.

I have the same home.g (includes all, x, y, and z) files that I have on my CR-10, which works flawlessly. I have my stalld-homing.g macro setup to reduce motor current and everything. (Inlcuding stalld-printing.g at the end of home files).

Do I need to have my print carriage move significantly quicker than on a cartesian machine? No homing file has any move with a F parameter lower than 3600.

Thanks,

Jordan.

oliof

@djstephenson1 sensorless homing on corexy works just fine. Look for the railcore blog where they have a sample homex.g/homey.g for sensorless homing. I used that as a basis for my vcore pro. My machine is off at the moment or I'd have linked to my files.

zapta

@oliof said in Sensorless Homing on a CoreXY:

... sensorless homing on corexy works just fine ...

What kind of stops do you get at the ends, soft quiet ones or more bumpy that sounds like a minor car crash?

I get a soft one on the X and a louder one on the Y, maybe because there is more mass moving (?).

My M915 is in line 54 here https://github.com/zapta/misc/blob/master/hevo/duet3/sys/config.g and the homing procedure is here https://github.com/zapta/misc/blob/master/hevo/duet3/sys/homeall.g .

macguyver

I use sensorless homing on my machine for now. The homing macros turn down the speeds and sensitivity so that it does not slam into the side. Usually it is nice and soft. That said I am going to install a homing switch eventually as they can be more accurate when using stall detection.

oliof

@zapta soft bumps on both.

djstephenson1

@oliof I am getting the full on car crash sound movement...

macguyver

@djstephenson1 Do you have an M913 in your homing file to reduce the voltage?

https://duet3d.dozuki.com/Wiki/Gcode#Section_M913_Set_motor_percentage_of_normal_current

Phaedrux

@djstephenson1 said in Sensorless Homing on a CoreXY:

@oliof I am getting the full on car crash sound movement...

Share your configs.

oliof

Here are mine

https://gist.github.com/oliof/53817f9214af0721b61722d8ea6c392c

X and Y are equipped with .9° 46Ncm 2A Nema17 steppers by OMC.

djstephenson1

@Phaedrux I will share shortly.

djstephenson1

@macguyver yes, I do

djstephenson1

This post is deleted!

zapta

@oliof, thanks for the config. I think I have same steppers. I increased the x/y homing speed from F2000 to F4000 and it seems to be gentler touch.