A30 downgrade from GT32Pro to GT2560 v3.0 and Marlin 1.1.9 installation

[Seriogal]

Hi All,

just to inform that it is possible!

For me it was forced decision. I tried to slightly adjust Extruder motor current and managed to burn out my A30 main board. As long as after 3 months of use I was quite tired about amount of bugs in official Geeetech firmware... I didn't wanted to restore the same configuration anymore. Big hardware modification was not an option for me as well (I wanted something where I could just plug existing wires and that's it). After quick investigation, I decided to give a try and upgrade my A30 with GT2560 v3.0 board used in A10 printer. I can confirm that all cables from A30 fits to this mainboard with minor exceptions - 2nd Z axis cable should be plugged to E1 connector instead of E2 connector in original GT32, filament runout sensor and 2x BL-touch cables 2pin and 3pin should be slightly modified (pinout is the same, but GT2560 have a bit different type connectors onboard, with longer distance between pins). As as original Geeetech display is not an open source, it was disconnected and left as it is to close hole in the case. As display/control point I selected TFT35 touchscreen/serial G-Gode controller (to connect it You will need to solder TX3/RX3/5V/GND connector to GT2560 board). Micro SD reader on the controller case was left unconnected as well, it is not needed when you use TFT35 who has USB and SD interfaces onboard.

I've attached modified version of A10 Marlin 1.1.9 firmware (to fit upgraded A30) and picture with connected cables for those who want to try doing this by themselves. Please do not expect any support from my side, I'm not often guest in this Forum.

PS I don't use BL-touch and Filament runout sensors. If you have them, you'll need to modify attached firmware accordingly!

Regards, Sergejus.

[William]

Hi, thanks for your feedback.

[TheG]

Given the issues that the Geeetech home-brew firmware has (like lacking important command, e.g. PID-autotune), I'd actually consider going back to a GT2560 with Marlin an upgrade, not a downgrade...

IMHO it would be wise by Geeetech to drop their self-made firmware and rely on Marlin, actively helping to develop that instead of yet-another-firmware-solution. If I had paid attention and noticed that the A30 is using a custom firmware, I would've chosen a product from another manufacturer.

Why re-invent the wheel, anyway?

[Seriogal]

Ahhh . Forgot . As long as Autotune function is up and running in my case... Please find below by settings for A30. Hope this helps :

Hotend:

#define DEFAULT_Kp 34.42
#define DEFAULT_Ki 4.77
#define DEFAULT_Kd 62.03

Hotbed:

#define DEFAULT_bedKp 192.15
#define DEFAULT_bedKi 37.83
#define DEFAULT_bedKd 243.98

[TheG]

Wow. You're a genius, why didn't I think about asking for the values! That might be super-handy, I'll modify my A30's values when I come home from work and do some test prints. Great thinking there!

Edit: You have the version with the 24V PSU, right? Looks like it from the picture, but better to make sure...

Edit 2: Those values are a LOT different from the original values set by Geeetech, I just hope their goofy firmware doesn't do some weird blackbox-math or the likes

[TheG]

Hi!

For your information: I've tested these values and they can not be used with the Geeetech default firmware. Good thinking there, but unfortunately the PID values appear to be interpreted differently by Marlin and this firmware Using these values, you get a dirty sinus wave where e.g. the extruder is set to 215°C and the temperature will scale from 205 to 225°C, while the heatbed set to 65°C will heat too aggressively and often be above the set temperature.

KR