MakerBot
Cupcake
Redux

The inspiration

The Cupcake CNC was my first 3D printer. I could never get decent prints but I had spent so many hours buiding it that I never had the heart to throw it away.

Ten years later, the pandemic-induced boredom during the summer of 2020 gave me the opportunity to give it a complete overhaul.

The prints are much better although no match for my other printers, a Luzbot Mini and a Prusa Mk3S. But like restoring a classic car, the journey was worth it!

Heated Bed

The Cupcake CNC used an acrylic build surface that was bolted onto a wooden build platform. I kept the original build platform but replaced the acrylic surface with a heated bed. The heated bed features a 5-pin connector for heating element and the thermistor.

To mate the heated bed with the original build platform I fashioned an adapter (STL) that attaches to the top of the original build platform with M3 bolts. The bolts of the heated bed slip through corner holes in the adapter.

I trimmed and cut a 12 cm square piece of an Overture print surface and stuck it on the heated bed. This surface provides good adhesion for PLA but make sure it wipe it with alcohol in between prints.

Heater (Top view)

Heater (Bottom view)

Adapter

Adapter on original bed

Final heated bed assembly

A New Extruder

Replacing the "plastruder" with the piggy-back controller board was the next obvious step. I picked up an inexpensive Geeetech MK8 extruder on eBay, fashioned a couple of mounts (motor-side STL, fan-side STL), and attached it to the original Z-platform.

The new exruder is controlled by a new main board so the original controller board mounted atop the movable Z-platform is no longer necessary.

This was also a good time to add a spool holder. I printed a couple of arms (STL) and inserted a 1/8" square rod into the grooves.

MK8 Extruder

Motor-side mount

Fan-side mount

Extruder on Z-platform

Spool holder arm

Spool holder

All New Electronics

The additon of the heated bed and the extruder replacement necessitated a new main board. The RepRap MiniRambo was the perfect fit, and is fully supported by the Marlin firmware.

I also replaced the original power supply with a 350W Mean Well PSU. Probably overkill for this setup but provides plenty of room for future experiments.

The motors and belts still held up after all these years but I could never get the bed to be perfectly level and required adjustments before almost every print. Picked up a BLTouch sensor and attached it to the Z platform right in front of the extruder using a mount (STL).

Thanks to "jwg3" for detailed instructions on wiring the BLTouch and configuring Marlin. I've include a picture of where the two connectors from the BLTouch go into the MiniRambo. Notice I had to switch the brown and red wires.

Changes to the Marlin 2.0.x firmware to support Cupcake Redux are here.