z axis crashing into bed

other post moved in here:

Quote
redblunt
now that i am ready to start my first print i zero z and run my setbed (who long does it take to finish? ran from the webserver it gets stuck did it manually then) so im set up to run ormaxis.g first the x axis move i think then the z axis sets down and crashes in the bed

Quote
dc42
If the z axis is crashing into the bed, it probably means that you don't have the right M558 command in config.g or your G31 parameters are incorrect. You may wish to comment the G28 homing commands out of ormaxis.g and home manually before printing.

Quote
redblunt
my config.g

; RepRapPro Ormerod
; Standard configuration G Codes
M111 S1;
Debug on
M550 POrmerod
;Set the machine's name

M551 Preprap;Set the password

M552 P192.168.178.55;Set the IP address

M553 P255.255.255.0; Set netmask

M554 P192.168.178.1;Set the gateway

M555 P2;Emulate Marlin USB output

M92 E420;Set extruder steps/mm

G21 ;Work in mm

G90 ;Absolute positioning

M83 ; Extrusions relative

M558 P1; Turn Z Probe on

G31 Z1.40 P684 ; Set Z probe height and threshold

M906 X800 Y800 Z800 E800 ;
Motor currents (mA)
T0 ;
Select extruder 0
M557 P0 X0 Y0

i homed manualy no success
i also recalibrated the zprobe no success

also tried printing from pronterface z crashes too.
i set G92 Z0 when the extruder was 5mm above the bed
also crashed - so it must be config or the sensor (says my mind)

when i start the print the z probe goes down fast (1 steps i guess)
when its nearly touching the bed it goes down slow (0.1 steps)
at this point its starts pusching down the bed and suddenly
z speeds up again to hit the bed witch (1step speed)

i know that the speed is messured differently still thats how it feels

---

Red Ormerod No. 281

Mods:
-My Bedsupport Mk2
-My upper z mount
-Davek0974s Aluminium X-Rib
-iamburnys Z Gears
-Form232-teks Cthulhu cooling ductg
-MasonStonehenges spring-loaded extruder

RepRapFirmware-0.78k-dc42,
web interface 0.99, Win7

Quote
redblunt
i set G92 Z0 when the extruder was 5mm above the bed
also crashed - so it must be config or the sensor (says my mind)

You have two choices:

1. Get z-homing using the IR sensor working reliably. It evidently isn't working reliably at present, because the G28 command in ormaxis.g is crashing the head.

2. Comment out the G28 command at line 24 of ormaxis.g, and then home X and Y and manually home Z before printing. To home Z manually, lower the head until it is just touching the bed, then send command G92 Z0.

Edited 1 time(s). Last edit at 03/31/2014 03:46AM by dc42.

---

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].

actually i want to go way 1. editing the z homing file; have to learn more about the scripting. is there something like if?


but i use method 2. at first:
test one deleted g21 still crashing
test two deleted g21 and g28 HE** YEAH printer is printing no bed crash *happy*

now its nap time :-) (smoke detector next to the ormerod)

thanks to dc42 - tomorrow ill continue with method 1 getting the z probe to work well