Klipper on Formbot T-Rex 3

Almost finished: Klipper on my T-Rex 3

With dual Z independent drive. I had TMC2209 UART running, but some short circuit costed me a printer board, 8 TMC2209 and LC display :frowning:

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Hi, since there are no new firmwares for the new Marlin 2.0.x from Formbot, I am also looking at installing Klipper. Did you make any progress?

Yes, it runs fine.
You can get it here:

You can ask me if you need more information. Here or on the Klipper discourse

Thanks for your quick reply! How is your experience so far? Is it worth the effort?

I switched to Klipper, because of missing steps/layer shifts during complex prints and the resulting high workload of the printer MCU.
The only effort was to find the correct pins for the controls. The Marlins sources are somehow misleading.

I needed a bit to find a good motor current, but the prints are all fine.

Once a profile is made, it's not quite the effort:
Just installing Klipper to the Pi running OctoPi/OctoPrint. Uploading the driver firmware to the printer and the the printer profile to OctoPrint.

You can run the T-Rex as it is with the TMC2208,
or you can upgrade to TMC2209 with UART (it's more ease with that to set the motor current) -> requires 6 new stepper drivers, some soldering and two wire looms for the UART,
or add an additional stepper driver for the 2nd z-axis. All with the original printer board (vivedino 1.1) -> requires a wire loom from the EXP1 port of the LCD

Hi Ewald!
Thanks for the detailed desciption. I think will give it a try after I built my first Voron which should give me some experience with Klipper anyway. Since I already upgraded to the 2209s I will also try out UART.

Thanks gain!

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Question I have the formbot t-rex 3, with the upgrade from formbot to the the T-REX 3+ that comes with the TMC2209 drivers, will your klipper UART setup work without having to solder or connect any jumpers??

Hello @Dres76 !

For I don't know the specifications of the new board, I can't tell.
I've collected my information from different sources. One of them was a source file of the Marlin firmware of the T-Rex 3.
Maybe you get a source file for the T-Rex 3+ to get the information for the appropriate ports for that board.

The board is the same board as the T-Rex 3, the + upgrade includes 6 2209 drivers and new wires for the heated bead.

I see, but if it uses UART, I don't know what ports are used.