Latest Firmaware Geeetech I 3 Pro C Dual Head GT2560 A+ with touch

[Al Kinnon]

Hello,

I have a home built Geetech I3 Pro C Dual extruder with various modifications to the extruder.
Software:
Repitier Host 2.1.6
Slicer 1.3.0
Arduiono IDE 1.8.13 (Win Store 1.8.42)

The newest firmware I could find was on the following page:
https://www.geeetech.com/forum/viewtopic.php?t=17046
the download preceded by ....
"6) Firmware for I3 pro C
Update:
Fixed the endstop error(Default endstop logic status is the"false")
2019/2/27
Marlin 1.1.8 for proC with GT2560VA/A+/2.0"

Without 3D touch my printer works well with very good results.

I'm using the provided configuration.h file for 3D Touch auto levelling, and can see the touch test option in the LCD menu. This does nothing on my printer. None of the M280 commands do anything.

Home for the X and Y work, however home for Z axis results in belt grinding, so I have to do an emergency stop.

The instructions geeetech published for 3d touch are quite old now and dont match up with the firmware described above.

Any idea what my issues might be?

Is there a config for the latest version of marlin or could someone advise what changes should be made and I'll have a go at the latest Marlin myself?
I would like to understand how marlin is configured to work on my printer so I can perform different updates.
Current stable Marlin version is 2.0.6.1 as of August 27, 2020

Thanks in advance for any help or suggestions.

[Ruffturn]

I recently replaced my controller board and loaded in the firmware on my three year old Pro C. I've got a BLTouch that I would like to install but I needed to make sure the printer worked with the new board. I'm interested in what you find out!

[Al Kinnon]

Quick follow up on this thread. I spent a lot of time at the end of March (2021) on this and achieved success.

I now have Marlin 2.0.7.2 running with a BLTouch clone sensor working on my Pro C Dual and getting decent results.
The process is not for the faint of heart, but is achievable.

Hardware
Ensure the wiring to your sensor is correct and all connections are tight. The geeetech guide on wiring is good, but you need to read it very carefully, there is soldering involved. Ignore the software configuration, its way outdated.
https://www.geeetech.com/wiki/index.php ... ing_Sensor

I wasnt happy with the position of the standard extruder bracket, so I made modifications, mounting the extruders lower down (I had to widen some holes to get the screws to fit). Take the clips off the corners of your printer bed when calibrating the height later on, otherwise you risk braking the sensor tip until you get your firmware settings correct.

I designed and printed my own mounting bracket for my touch sensor. My design allows the touch sensor height to be easily adjusted vertically in relation to the extruder heads.
https://www.thingiverse.com/thing:4906172

I recommend setting your sensor high to start with

Software
The old arduino software is useless for newer firmwares and full of bugs.
For the more modern firmware updates, use Visual Studio Code with PlatformIO.
https://marlinfw.org/docs/basics/instal ... scode.html

When setting up your PlatformIO environment (discussed in the above guide), I used ...

Code: Select all

default_envs = mega2560

I've attached my configuration.h file for examination. bare in mind my extruder head position is likely to be different to what you have, so take the time to learn the important settings; I take no repsonsibility for you messing up your printer.

NOZZLE_TO_PROBE_OFFSET is something you are going to want to pay particular attention to. I have mine set to:

Code: Select all

#define NOZZLE_TO_PROBE_OFFSET { 15, -70, -1.34 }

It took me a while to work out the z offset of -1.34, but this gives me a really good starting gap without poking paper under the nozzles.

Once you have uploaded your firmware successfully your z movement will be all wrong.
To fix this run the following gcodes:

Code: Select all

M92 Z400
M500

Your menus on your printer will now have lots of new options.
The z offset for your touch probe sensor can be tweaked to find the sweet spot in the menu Configuration->Z Probe Offset. Every time I made a change to this value, I would use the store option, then reset the printer and double check the new value was still there before trying to home the printer or running a test print.

Keep a close eye on it when your testing to avoid damage to your bed or sensor and make sure you have a way to stop it dead if something goes wrong.

Once the results were coming out consistantly decent, I removed the spring screws from all four corners and put in spacers and cable ties, and no longer have to worry about bed levelling.

Every so often I still have to ensure the horizontal bars which carry the extruder are level, as the z motors dont move at exactly the same speed. This is a minor adjustment that only takes a moment using a caliper.

I thought I should share, and hope this information is of use to someone.

Regards,
Al