Well there were at least two reasons that lead to this project. I was playing with different kind of GRBL controllers based on STMF1 Blue Pill and ESP32 and i wanted some hardware to easily test them. On the other hand i was cleaning up the workshop in the basement from former CNC projects and found some leftover linear guides, trapezoidal spindles, NEMA 17 and 23 Steppers etc…

After drawing down some ideas i ordered some aluminum extrusions matching the 300 and 250mm rails i had laying around. With the profiles ordered to the matching length i finalized the drawing of the small Milly CNC with a footprint a bit bigger than an A4 paper.

The Plan is to fit all needed electronics into the base of the CNC. This means the power supply for motors and spindle as well as the full CNC controller. I guess it will the the GRBL ESP32 with SD-card and Webinterface/Wifi, which makes this machine completely self contained.

Front and back, flanges and some other parts were milled out of 8mm HPL. The Working plate is build out of 2080 and 2060 profiles which hold the MGN15 rails of the X-Axis. After trying to build the portal with 6040 extrusion and 8×8 trapezoidal rods, i changed that to 4080U extrusion which has enough space to run an SFU1204 Ballscrew inside the profile and still have enough room to fit the MGN12 rails of the Y-Axis.

All Electronics were mounted on the back side. 36V 7A PSU on the left and a printed mountplate with ESP32 + grbl Shield, 5V regulator and a FET to control the spindle on the right side. On the front there is the main power switch on the left, GRBL buttons for reset, hold, start on the left.

Frame

• HPL High Pressure Laminate 8mm for front/back/side-plates
• https://www.motedis.com 30€ incl Shipping
  • 1x Aluminum Extrusion 60×40 I-Typ Nut 5 252 mm
  • 2x Aluminum Extrusion 20×80 I-Typ Nut 5 300 mm
  • 1x Aluminum Extrusion 20×60 I-Typ Nut 5 300 mm
  • 2x Aluminum Extrusion 20×20 B-Typ Nut 6 300 mm
  • 21x Nutenstein Glatt I-Typ Nut 5 [M5]

Linear Guides

• MGN15 300mm MGN15H 2x $13
• MGW15 150mm MGW15H $26
• MGN12 250mm MGN12H 2x $9
• 20x M3 Slot Nut for 2020 Slot 5 profile 3x $3

Trapeziodal spindels

• T8x2 Lead Srew with nut 300mm 2x $6.5
• Shaft Coupler 5mm 8mm 2x $2
• KFL08 bearing block 8mm 2x $1.5

or

Ballscrew spindles

• SFU1204 350mm $13
• SFU1204 300mm $13
• Shaft Coupler 5mm 10mm 2x $2
• KFL08 bearing block 8mm 2x $1.5

Electronics

• NEMA 17 Stepper Motor 48mm for X and Y 2x $12
• ACT 16hsl3404 Linear Stepper Motor for Z Axis 15€
• 36V 7A 250W Switching Power Supply 14€
• Arduino Uno + NC Shield + 4x DRV8825 drivers
• Micro switches
• 12mm push button 3x
• 16mm latching push button

test-running both axis with TR8x8 spindles