Gamma axis moving backwards only during prints

(mlapaglia_SW) #1

smoothieboard 4x configured for a delta printer
Here’s a quick pic: mattlapaglia dot com /wp-content/uploads/2015/02/IMG_20150208_223541 (dot) jpg

The three towers home correctly towards the max end stops. Moving the effector around manually works as expected. When I try to print an object the gamma axis always jams upwards while the other two axis perform normally.

I’ve switched the end stops and motors around to make sure it wasn’t anything with those particular components.

Here is some gcode from Cura, set with the “hardware center at 0, 0” checked in the config:

M190 S70.000000
M109 S230.000000
;Sliced at: Thu 18-06-2015 15:31:36
;Basic settings: Layer height: 0.2 Walls: 1 Fill: 10
;Print time: 2 hours 30 minutes
;Filament used: 3.527m 27.0g
;Filament cost: None
;M190 S70 ;Uncomment to add your own bed temperature line
;M109 S230 ;Uncomment to add your own temperature line
G21        ;metric values
G90        ;absolute positioning
M107       ;start with the fan off
G28   ;move to endstops
G92 E0                  ;zero the extruded length
G1 F200 E3              ;extrude 3mm of feed stock
G92 E0                  ;zero the extruded length again
G1 F9000
;Put printing message on LCD screen
M117 Printing...

;Layer count: 201
G0 F9000 X22.208 Y-17.235 Z0.300
G1 F1200 X22.719 Y-16.569 E0.01974

If I execute the G0 command manually, it performs as expected. When I execute the actual gcode file though, the gamma axis pushes up into the end stop, forcing me to shut off the machine.

I upgraded to the latest stable firmware and started from a fresh config file for the delta style printers.

Any help would be appreciated!

Imported from wikidot

(mlapaglia_SW) #2

Figured out this is (another) hardware issue. The dir pin on the stepper randomly switches, making “up” commands go down and vice versa.

This is the third smoothieboard I’ve had. The first one had a dead stepper, the second one randomly resets, and this one has another bad stepper.

I’m returning all of these and going with another controller next time. The lack of QC on these boards is horrible. I’ve had two RAMPS and one RAMBO for over a year without issues.