The Z-Probe ran fine but impact with my glass when print!

fanofcc

Hello! I want to use Repetier Firmware for my new 3D printer, but i faced a problem with the Z-probe function.

Here is my Probe system:

- I use a aluminum hot bed, solded a wire between the hotbed and connect it to GND on my Ramps.

- I use an other wire to connect the extruder with Z-min Pin on my Ramps. So when the extruder touch the hotbed, this system act as a mechanic switch and can be use for Z-probe.

Here is my config: https://drive.google.com/file/d/0B3jY5m-ty2usUzdpWnQ2SXBYOGs/view?usp=sharing

- I use Z endstop on top of my machine and config it in Repetier firmware (0.92.8) as Max Z endstop. Also i disable the min Z min endstop and Z-min pin on Ramps.

- I use the Z-min pin on my Ramps for Z-probe.

What i want to do:

- I want to Z-probe and save on eeprom so i don't need to auto leveling every time use the machine to print.

- I want to have a LCD menu that i can use to do the Z-probe when i need.

- When Z-probing i will remove the glass (so the extruder and the aluminum hotbed can touch together) and will put it back when i print. The glass thickness is 4mm so i want the Machine offset this thickness when print.

The problem are:

- The default LCD menu don't have Z-probe function so i have use Repetier Host to do this.

- On Repetier Host i use "G32 S2" to start the Z-probe. The machine z-probe ran smooth and completed.

- I set the Z_PROBE_Z_OFFSET to 4mm (the glass thickness), set the Z_PROBE_HEIGHT to 0 mm (the extruder touch the hotbed when triggers).

- But when put back the glass and print, the extruder go down and impact with the glass.

Please help me:

- How to fix this problem and get a correct config?

- How to put a LCD command to do the Z-probe?

I'm not the coder so please tell me simple!

Thanks you!

RAyWB

Hi,

as the level after mounting the glass panel is 4mm higher as the level you probed before you have to set
Z_PROBE_Z_OFFSET 0 and Z_PROBE_HEIGHT to - 4mm.(the probed level is lower than the glass surface which should be 0 ).
I tested it on my printer with G29 S2 , works well.

best regards,

RAyWB

fanofcc

Great, it worked like a charm :)

Anyway, how to add a command enu on the LCD? Could you help me more?

Thanks!

RAyWB

Sorry, not at the moment. I´m working on this but i´m low on spare time

RAyWB

just a question to your probe setup..
do jou have an optocoupler installed on your probe pin?
just for the case your heating nozzle will break and the +12V or 24V have contact to extruders nozzle
you will toast your controller....

unfortunately I´m very experienced in this special case... i killed 2 DUE´s that way

what type of controller do you use? are there buttons for free use?
it would be easier for me to assign the zprobe function to a button without displaying it.
I´m not shure to get the UIMenu done.

best regards

fanofcc

Oh thanks :)

My probe mechanic is very simple:

- The nozzle is connected with Probe pin (i use Zmin pin for probe).

- The hotbed connected with the GND pin.

- When the nozzle touch on the hotbed, they act like a simple mechanic switch (close the GND pin and the probe pin and change the logic on the probe pin).

I use RAMPS 1.4 controller.

Can you tell me more about use a button to start the probe?

Thanks you again :)

osnwt

I think that is the answer to your question: http://forum.repetier.com/discussion/1808/a-guide-to-add-a-simple-menu<br/>The example shows exactly the menu you need.

Repetier

The bed coating trick did not work because the correction of z length was missing (assuming you home z max). I have fixed that now. So now it should think it is 4mm lower preventing the crash.

fanofcc

@Repetier:

Oh i did some tweak when probing and it work:

- First, i reset all setting (factory eeprom)

- Second, i set the bed coating value back to 0mm

- Third, run G32 S2 (probe)

- Fourth, set bed coating go to 4mm

And then save all setting.

It worked very good!