My first Print - but printing on back of bed!

Hi all,

Well the big moment arrived for me yesterday when I finally had the opportunity to load my cube gcode file into Pronterface and hit the "Print" Button for my first time. I was really excited on how well my cube came out in the end (for a first print), but as you can see from the photo it almost fell off the back of my print bed. X axis was perfectly centered, but obviously not my Y.

I have been scouring my settings in the Marlin configuration.h file, Slic3r (0.9.8), and within Pronterface itself. I am stuck as to what I might be missing and would appreciate any thoughts. I have an 8x8 bed (essentially 200x200). I have included information from the spots I am aware of (Newb - first build). Here are they are...

From configuration.h

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1

#define min_software_endstops false //If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops true //If true, axis won't move to coordinates greater than the defined lengths below.
#define X_MAX_LENGTH 180
#define Y_MAX_LENGTH 180
#define Z_MAX_LENGTH 100

// The position of the homing switches. Use MAX_LENGTH * -0.5 if the center should be 0, 0, 0
#define X_HOME_POS 0
#define Y_HOME_POS 0
#define Z_HOME_POS 0

Settings in Pronterface Defaults - build_dimensions 200x200x100+0+0+0

Slic3r - Printer Settings
Bed Size x:200 y:200
Print Center x:100 y:100

If this is relevant, I did notice that I can Home my X and Z axis just fine within Pronterface. (moves along, bumps, and then stops) However, when I try to home the Y axis, it move about 10mm and stops. (in the right direction towards the end stop) Also I am using my E-Stop instead of my Y-Stop (in case that might be part of the problem) on my Printrboard Rev D.

I appreciate your consideration.

Can you enter some g code interactively to see what you get?

Enter G1 Y0 F3000 and it should move to the front edge of the bed

Change the y value to 200 and it should move to the rear of the bed. This should give you a hint about the accuracy of the y axis calibration.

You might want to lift the print head a bit before trying the commands: G1 Z20 F1200

Thanks jbernardis,

I appreciate the reply and I am totally with where you are going with this. I did put the bed on the back edge and then sent the gcode. My bed went all the way up to the front edge - back and forth, all good to go. I thought I had been fanatical with the calibration of my axis, so after my first print I went back and checked my firmware and then did actual commands and measurements. 10 mm in Pronterface went 10mm on the bed, 25, 50, 100, etc. all good. (my cube was even perfectly square in the X and Y axis)

I did just retry the Home buttons on Pronterface. Once again X and Z were great, but my Y only moves 10mm forward at a time - Hit Home - 10mm more, and so on and so on.

Is there a way to set home positions within Pronterface? I haven't seen a lot of places to do much of any changing, but the one in default settings that I had posted.

Thanks for listening (reading).

The home buttons are what tell it to move to home. The actual underlying command is g28, and basically says "move until you hit the end stop and set that position to home."

The g92 command basically says "set the current location to home". It takes one or more axes, such as g92 x0 y0, and I don't know what happens if the numeric value is nonzero. It probably just set the current axis location to be that value.

Your description sounds as if you might be having trouble with the end stops. Once you hit the home button, the only thing that should make it stop is running into the end stop. Command m119 can be used to query the end stop status.

Brilliant Jbernardis!

I had a second before I ran off to work for the day and I sent the query for my end stops. Here is what I got....

SENDING:M119
x_min:L y_min:H z_min:L

I tried depressing the Y endstop and it still gives a High feedback. So I guess I have a bad endstop switch. When I get back tonight I will have to order a few (get some back ups).

I am going to call this mystery solved.

Thanks so much for helping out a rookie printer!