Reinventing my 2010 MakerBot Cupcake CNC 3D printer for 2020 and beyond!
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.
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.
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.
The final assembly
Here are photos of the finished upgrade.