Quote Originally Posted by TopJimmyCooks View Post
Working on another i3v - Identical to my 8" except it's a 10", bought at the same time last summer. We were having problems with the G29 not working. When you run the g28, homes all axes normally. when running g29 directly after g28 using the pronterface terminal:

*x axis moves into position, but y axis stays at home position (Y0, where the probe points are at y50, 100 and 150 for a 9x9 grid in the firmware).
*probes the 3 X coordinates given in the firmware but the y axis never moves. So it probes 9 times moving back and forth in a line at y0.
*at that point the nozzle is still at y0 geographically but thinks it is at y150 per the LCD, where it would normally be at completion of successful ABL

Comments:
*This firmware works correctly on my 8".
* i checked the wiring, everything is identical. endstops are on the same ends, set up to home at the back right corner just like mine. bone stock i3V basically except the servo upgrade.
*the 10" printer works fine and prints with fixed z endstop and stock firmware when flashed.
*everything moves around fine under pronterface control.

We're stumped and appreciate any ideas. Thanks.
Been there. Done that. Un-comment this line:

Code:
//#define DISABLE_MAX_ENDSTOPS
I struggled through the same issue a couple of days ago on a new i3 built with a leftover frame from my i3v upgrade and cheap eBay electronics. The default config on the beckdac fork has the max endstops enabled, but without pullups enabled or anything connected to the pins, they're just floating, apparently picking up ground noise from the motors. I spent a lot of time debugging and figured out that the firmware is reading a max endstop trigger during the move away from home, usually on Y. The homing routines don't check for this, and just assume everything is fine.

I submitted a pull request to the beckdac repo to disable the max endstops by default.