EDIT1: uploaded a V2 version for Y belt 10mm from my original mod. Step file updated too
EDIT2: Tbgs Carriage is complete, the step file is avaible, the mod is on testing, after some tests the stls will be relased
IMPORTANT UPDATE (Update3): Added a version for better homing (Black Phantom X pass idler and motor). Also suitable with MK3s stock firmware and einsy board
This is a project i did to evolve my MK3s to Duet as an alternative upgrade, instead of the MK4, to get WebUI, Input Shaping, Accelerometer support, Preassure Advance, Macros & Plugin.
Some mods are designed by me, some remixed and modified.
Essentially i used the Mk4 Printed Parts and reworked to fit with 8mm rods of mk3s, and a Linear Rail 350mm 1x MGN12H Block.
The electronics are based on Duet 2 Wifi and PanelDue 5". You can get a nice clone from bigtreetech here. For 80Euros you will get the board, the wiring cables and the PanelDue 5".
https://s.click.aliexpress.com/e/_DelXQQd
Or You can buy the original one here(it is up to you)
https://www.duet3d.com/duetwifi
For the Y parts i used the linear rails, 2x330mm, and 3xMGN12H block, as described in the original mod. I reworked the rear parts for the square nuts easy fit.
For the Y belt, i modded the mk3s printable parts to use a 10mm GT2 belts. I did some tests with accelerometer and i noticed that the 10mm belts suffer less the bed mass increase while printing(typical on a bed slinger printer). That's helps to stay in to the Input Shaping working range(EI2 or 3 and ZVDD or ZVDDD are the best way to go here).
You can get some decent and not so expensive rails from RDBB here
https://s.click.aliexpress.com/e/_DCMvEiN
For the Extruder you can obviously use the stock MK3s extruder, and yes the filament sensor and the PINDA or SUPER PINDA are compatible with Duet.
Otherwise for a lightweight choice you can go with the Zorbiter(better the 2.0 edition), like the one i used for the Step file.
I STRONGLY suggest to swap the cooling fan, even if the 5v fans are still usable and compatible with Duet(Use the jumper to work in 5v mode). I would definetly go with something decent on 24V (like a Sunon https://s.click.aliexpress.com/e/_DDUdh85 ).
I also suggest to add 2x0.9° motors (i found a pretty nice solution that works well from trianglelab https://s.click.aliexpress.com/e/_Ddm11MH ). The top choice here is the LDO 0.9.
If you would go with the kit from Bigtreetech, 2x Trianglelab Motors the total costs is around 120-130euro for all the electronics upgrade.
The linear rail parts, the Zorbiter, and the 10mm belts are not mandatory, and you can obviously use the stock mk3s parts. Maybe just for a lightweight carriage i would consider the Zorbiter the most relevant of these “plus” with just 1x linear rail on X carriage to use the Mk4 printable parts mod i did with this pourpose(for an extra 100euro). I clearly (XD) did all these upgrades(at moment with BMG mod, but i will upgrade to zorbiter, i'm just waiting the Orbiter 2.0)

Just a couple of little considerations, the Y Linear rail mod is not really easy to assembly in the right way, and if you will end to assembly the rail not in line, well maybe It Is far way better to stay with the smooth rods.

For the Duet you will need to crimp at last the PSU and Bed cables. Follow the caribou tips for duet wiring(look the image or caribou site)

For accelerometer you will need an LIS3DH or LIS3DSH

https://s.click.aliexpress.com/e/_DlLx7A9

I will add later the configuration for duet, but you also can find an easy way thnks to Caribou
https://caribou3d.com/en/content/13-caribouduet-software

I will update this project when i will have some news