Pancake Flipper

An upside-down toolchanger printer with belted Z axis

Made by: @tmshader (GitHub)
Repository: https://github.com/tmshader/pancake-flipper
Total hours so far: 44

I have a 3D printer or will be getting one before March 21st

Log

Day 0 - Big research day

(2025. 03. 06.)
Hours: 10

Started planning out the printer (a bit late for Infill tbh 😅). Done a lot of research today and some CAD work.

The current plan is the following:

Upside-down design
Fits into filament box (200 x 200 x 70)
2 extruders with toolchanger
- mechanical or electrical toolchanger <- to be decided, but mechanical is preferred
2020 and 1020 aluminium extrusions for structural rigidity and stability
3 linear rails for precise motion on all axes
1 belt for X and Y axes and 1 belt for Z axis
Positron-style XY kinematics
Positron hotend
Eddy current bed leveling
BTT SKR Pico v1.0 controller
Rasberry Pi Zero 2 W main board
Integrated power supply
Enclosure
- Fitting into the same filament box is preferred, but might not be possible
- Not 100% planned out yet
- Might not be included in final design

Day 1 - First mockup of mechanical components

(2025. 03. 07.)
Hours: 5

Found models for the linear rails, steppers and extrusions. After putting together a quick model I realised that the 1020 extrusion option is not viable for this printer, so I’m going to be using all 2020 extrusions.

Working on the placement of the Z stepper and the two extruder steppers. Tough problem. I need to make it fit into the filament box, but also have 5 steppers, 2 control boards and a power supply in the foot of the printer. I’ll continue working on it tomorrow, it’s gonna be a fun problem to solve.

Day 2 - Iterate, iterate, iterate

(2025. 03. 08.)
Hours: 9

Switched to two 1030 extrusions for the Y and Z axis as they are flatter but also fit my original idea, which the 1020 extrusion did not.

Changed out the linear rails for 3 different types instead of using the same type for all axes. This makes the printer stronger and more precise.

I’m having a hard time designing the Z axis belt stepper and the two extruder steppers. It is hard to fit them all into the base, so I’m trying to put the extruder steppers on the Z axis but that also introduces problems.

Day 3 - Bye bye Z belt

(2025. 03. 09.)
Hours: 10

I spent the whole day researching printers, searching for parts and trying out different configurations for the Z axis belt. Sadly the solutions I came up with were either too expensive or did not fit into the volume that I want for the printer.

Because of this I’m switching to a lead screw for the Z axis.

RIP
Z axis belt
(2025 - 2025)

Day 4 - Powersupply and motion system shenanigans

(2025. 03. 10.)
Hours: 6

I chose the powersupply to be included in the printer. I picked a 300W 24V one so I have enough headroom even for the two hotends. It will possibly require a little modification to fit the printer, but not something that cannot be done with tools anyone building a 3D printer should have.

I split the Y axis extrusion into two 100mm parts so that the cables can pass through the 50mm gap left between them. The cables are for the power supply and one extruder and it’s hotend.

I started planning out the specifics of the hotend and the toolchanger and I think I’m going to have just the one part cooling fan and attach the hotend to that somehow. I do need to have two toolhead PCBs because that way I can pre-heat the hotend before changing and the downtime will be way lower. The part cooling fan will have it’s own wire and PCB which will contain any components that are required on the toolhead but not specific to the hotend, such as bed leveling sensors or possible LEDs.

I’m currently designing the belt path and the tensioner for it. It’s quite fun routing and modeling the belt and picking out the different bearings, pulleys and idlers.

Day 5 - Belt, idler, pulley… belt, idler, pulley…

(2025. 03. 11.)
Hours: 4

The belt path for the printer has been adjusted and tweaked and I think it is now close to done. I might have to make slight adjustments once I get to the modeling part of the planning phase, but for now I’m satisfied with how it looks and behaves.

I changed and modified the position of most pulleys and idlers. This way the assembly should be easier and less parts are needed, which makes the printer cheaper in return.