How to get my printer to home


#1

Hi I am new to octoprint I have set up the raspberry pi 3. I have octoprint up and running but I cant get the printer to home by tapping on the home buttons when I tap on the home button the x/y and z just go back to the stop switches and stop and don't go to the home spot. but if I put G28 code in it homes spot no . is there anyone who can help ne please


#2

What does your printer do if you send it G28 X0 Y0? I believe that's the line OctoPrint sends when you hit the main "Home X/Y" button.


#3

hi if I put G28 code in it homes as it should if I try to home xz axis the home tab it dose not move at all if I hit the in the middle of the x and y it just hits the stops and that's it


#4

Sorry to repeat the question, but what does your printer do if you put G28 X0 Y0 instead of just G28? I'm trying to differentiate if OctoPrint is sending a different command than you expect or if your printer is handling the expected command differently than you expect.

Also, what kind of printer do you have?


#5

ok sorry not doe that I have just put G28 I will boot it up and give it a go and get back to you


#6

have just put in G29 x0 y0 and it just hits the stops and stays there I all so put in G29 XO YO and G29 in upper and lower case but they just hit the stops and stay put


#7

When you say you put in G29 x0 y0, did you mean G28 x0 y0? If so, and your printer reacted the same way as it does when you hit the home button, that means that OctoPrint is sending the expected command, but your printer is interpreting it differently than might be expected.

What kind of printer do you have?

Are you using the OEM controller and firmware or have you changed to something else?


#8

hi I have a tronxy p802ma and yes I put in G28 AND NOT G29 SORRY I have been using repetier with no probs ii have just updated to raspberry pi with octoprint every thing seems to work apart from the home tabs. sorry I do not know what you mean by OEM the firmware I use is marlin hope this is some help thanks


#9

It looks like there was some discussion around G28 X0 Y0 Z0 and G28 with Marlin and Repetier a while back:


https://github.com/repetier/Repetier-Host/issues/105

As far as I can tell, though, both of those are problems with the commands behaving as expected and hitting hardware limits of delta machines, which isn't really relevant here. G28 homes all of the axes at once. G28 X0 Y0 Z0 homes the axes one at a time, in the order presented. To complicate things further, this seems to be in contrast to older machining interpretations of G28 Xx Yy Zz, which would home all axes, passing through intermediate point (x, y, z) to avoid running into any features on the machined part.

OctoPrint sending G28 X0 Y0 is deliberate because that button is meant to home only the X and Y axes only. You say when you click the Z-axis home button that your machine doesn't do anything, even if the Z-axis isn't at the endstop or your configured home position?

What it sounds like to me is that your machine is applying a pre-configured homing offset on a plain G28, but that offset is not being applied if G28 is sent with axis parameters.

What happens if you send your printer G28 X Y?

So far as I can tell (I've never run Marlin), Marlin does not support axis coordinate parameters for G28, but instead treats the axis labels as flags. If that's the case, I would think it would just ignore the 0s, but I'm not sure.

http://marlinfw.org/docs/gcode/G028.html

Can you share the output of M503?

http://marlinfw.org/docs/gcode/M503.html

I'm particularly interested to know what the offsets are set to, as described in:

http://marlinfw.org/docs/gcode/M206.html

Also, can you share the values of your Z_SAFE_HOMING, QUICK_HOME and HOME_Y_BEFORE_X settings? These may be included in the M503 output, but I'm not sure.

We may need someone more familiar with Marlin to chime in on this thread.


#10

ok thanks I will have a look at the links and a good look at GitHub I have now found another prob as in I can pre heat the bed and nozzle but as soon as I put a print going the heat turns off and the print will not go


#11

What slicer are you using and what is your startup gcode block?


#12

HI I HAVE JUST STARTED USINN CURA 3.2.1 I am just about to try and use cura with a usb cable to see if it works as I have been using repetier . ihope this is what you mean by startup gcode G28 ; Home extruder
G29 ; auto level
G1 Z15 F{Z_TRAVEL_SPEED}
M107 ; Turn off fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
{IF_BED}M190 S{BED}
; Activate all used extruder
{IF_EXT0}M104 T0 S{TEMP0}
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
{IF_EXT0}M109 T0 S{TEMP0}


#13

I have got rid of {IF_EXT0}M109 T0 S{TEMP0} and it kept the bed and hot end up to temp when I put a print going but it started to print in the front left side of the bed part of the print was off the bed. R well I mite know what I am doing by the time I (sorry we) get it going as it should . lol


#14

Your startup gcode looks like bog-standard Cura, so that should be good. What does your Cura config look like? If removing the lines that set temperature in the startup routine makes things better, then Cura probably isn't configured properly for your bed and extruder.

With respect to printing off of the bed, there's probably somewhere in the settings to set the bed dimensions as well. When you home (G28) then send the head to the origin (G0 X0 Y0), where physically does the head go?


#15

when I home it .it goes about 150mm from the front to the back and about the same from the left to the right. I have set the bed dimensions in the printer settings I have been look at the settings in my repetier cura settings and the settings the cura 3.2.1 that I am using with octoprint I have not seen anything different yet