X and Z Axis Homing

Hi everyone,

I finally got my Ormerod running and good temperature but i'm facing a new problem :/
i will first show you my homing files and then i will explain you my problem:

homez.g

M120 ; Push - save the current feedrate and relative/absolute move status
G91 ; set movements relative
G1 Z5 F200 ; move upwards 5mm at 200 mm/min to make sure we don't hit anything
G90 ; set movements absolute
G1 X55 Y0 ; Move to the X, Y point at which to probe the bed over the foil
G30 ; Move down until the probe is triggered (i.e. move down until the IR voltage is 656, which automatically sets Z = 1.8mm).
G1 Z0 F200 ; Move down to Z=0 (i.e. move down the last 1.8mm)
M121 ; Pop - restore the feedrate and relative/absolute move status

homex.g

G91
G1 Z5 F200
G90
G1 X55 Y0 S1
G92 X0
G91
G1 Z-5 F200
G90

homeall.g

G91 ; set movements relative
G1 Z5 F200 ; move upwards 5mm at 200 mm/min to make sure we don't hit anything
G90 ; set movements absolute
G1 X10 F2000 S1
G92 X0
G1 X3 F200
G1 X50 S1
G92 X0
G1 X20 F2000
G92 Y0
G1 Y250 F2000 S1
G92 Y200
G1 Y197 F200
G1 Y250 S1
G92 Y200
G1 Y0 F2000
G30
G1 Z5 F200
G1 X0 Y0
G1 Z0

The Y homing is working perfectly.

So here is my problem, when i want to home X, it just goes further to 55mm instead to position itself to X55 Y0, From here we could say there is an X Origin problem but even if i set G92 X0 to the beginning of the X Axis it works when it is at the beginning but it's not working when it's somewhere else :/

The problem appears as well when i want to home Z because we need that particular position for the IR sensor.

Thanks all per advance for your help !

Do you have an Ormerod 1 or an Ormerod 2?

You appear to have added "Y0" to the homing line in homex.g. Why? That probably explains your problem.

I suggest you restore the homex.g file to the version appropriate for the machine you have and the firmware version you are running.

---

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].

I have an ormerod 1

I will try your suggestion as soon as I'm next to the printer

If i don't add Y0 to homex.g that's no big deal but for homez.g I surely need it but it just keep going further 55 instead to position to X55 Y0

On startup your printer has no idea where the axis are; they could be anywhere so they are set to 0. You have to move them to a known point. In case of the y axis it moves way out to possition 220 until it reaches an endstop. Which it does encounter because the Y-axis is only 200mm long.

This is done with the line

G1 Y220 F2000 S1 ; move to position Y 220 or until endstop
G92 Y200 ; define endstop position as Y 200
G1 Y0 ; go to position Y 0

you have to use this during your x-homing, too

G1 X-240 F2000 S1 ; move to position -240 or until endstop
G92 X0 ; define this position as 0

See the negative value of the X-Axis movement? This is due to the fact of the endstop beeing at position 0. In case of your printhead beeing at the front of the arm, you have to move the whole length back to the endstop position.

Your code moves 55mm forewards or until it reaches an endstop. there is no endstop at the max value of the x-axis.

Controlled moves like Y0 X55 are only correctly possible when your axis are homed.

I have restored the files by the origin ones and it worked once and then after when i home X and Y, they go both in the mounting, i always have to shutdown the power to stop it :/

Have you checked your wiring? Are the motors turning the way they are supposed to turn? What is your Z-Probe value?

I'm pretty sure about my wiring i checked many many times and all axis homing worked once and then not anymore

My Z-Probe value is 681

Your Z probe value is quite high - it's best to aim for 600, rather than 700. The same value is used as the trigger for the X axis homing, and if it is too high, the X home position will not be seen. If X axis homing is not working, make sure you have placed a white reflector (white paper, adhesive label or Tippex) on the bar that sticks out of the x-motor-mount; this triggers the sensor. The commissioning instructions say to do this. If the sensor misses the bar, it can push the housing off the pins of the sensor - check this is still sitting on the sensor, or it will mess up the Z homing.

Ian
RepRapPro tech support

Indeed i've missed this sentence:

To ensure reliable X homing, you will need to add a piece of paper or adhesive label (like that used on the bed) to the top of the bar for the sensor to work consistently.

Does it mean i have to put it on the Z Axis but at the level of the X Axis ? (Sorry i'm not English native)

I will try your suggestions out tonight

You have to put it where the red circle is.

Hmm... I think I'll have to add a picture to the commissioning instructions. Sorry it's not clearer!

Ian
RepRapPro tech support

Many Thanks to all !

All my Axis homing are perfect now !

Just by adding a piece of paper as DasBasti said and decreasing a bit my Z-probe