[3D-Print] Custom geeetech i3 printhead and some other stuff

This summer I bought a prusa i3 clone from geeetech, a cheap chinese printer manufacturer.
With 270€, including VAT and shipping, the DIY-kit is quite cheap and 8 hours later i had a prusa i3 clone that prints “quite okay”.

[more here]

This printer has a direct drive, bowdenless MK8-style extruder. While it prints really good, I wanted to have more flexibility.

So I started to design my own printhead with these constraints:

  • exchangeable modules for: E3D v6 hotend, dual E3D v6 hotend, E3D Cyclops, plotter, laser cutter (more), …
  • modules should be easy to change (no soldering, possibly no screws)
  • no rewiring when changing a module
  • lightweight design
  • easy to service

These lead me to a three-component setup:

a) The X-Axis carrier.
Into this thing go all the screws. The SC8UU housings for the LM8UU linear bearings get mounted there, the belt attachment and the other printhead parts are mounted onto it.


The X-Plate with a lot of holes for M4 screws in all variants

b) The thing I call “Baseplate”
It is the electrical connector that holds the printhead in place with magnetic force.


The Baseplate with Ingun pogo pins and neodymium magnets

The Baseplate holds up to 30 pogo pins “GKS-967” from Ingun and each two “Q-10-04-02-N” and “Q-15-15-03-N” neodymium magnets from supermagnete.de.
The layout of the connector is designed so printheads can be plugged in either of the two connectors, having the same pinout on both.


This EAGLE PCB was later redrawn in Altium by a friend who ordered a larger panel anyway

The pinout for every module has 9 “center” pins that are for the important lines – heater, thermistor and fan supply.
The “outer” pins are for optional (extruder) stepper motors and some spares for future use.
If i want to re-use my (clone)original MK8 extruder and hotend, i can simply put it into a proper adapter and plug it into the baseplate :)
Already made a proper mount for the original MK8 extruder that gets snapped into the base plate.

The pads you can see in the upper part of the PCB are the solder pads for the flexband I scraped from Audi/Volkswagen steering angle sensors.
One of the next steps is to use five flexbands and solder them onto the PCBs. I have the same PCB twice, one in the baseplate and one next to the printer’s main PCB.


No idea where to get such flexbands from officially – scrapyard?

c) The printhead modules
These – I only designed E3D v6 and Cyclops yet – are easy to unplug


One module – a classic E3D v6 – plugged into the baseplate


Two E3D v6 modules and a E3D Cyclops above them for size comparison


Here a video of the current status, feels quite stable thanks to PETG which I can absolutely recommend.


…more later when I finished mounting and soldering the whole thing.


[Update: 03.01.2017]
Here a (a bit too artistic) photo of the printhead with flex bands attached:

And here some of my printheads

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