MultiBot CNC by reality_boy

Last crawled date: 3 years, 3 months ago

**** Note, there is a new version of this project.
https://www.thingiverse.com/thing:4645791
This is a mostly 3D printed CNC Router that was heavily inspired by Nikodem Bartnik's DIY Dremel CNC, however all parts are original designs by me.
https://www.instructables.com/id/DIY-3D-Printed-Dremel-CNC/
The goal was to make a low cost CNC machine that used only easily obtainable parts. I tried to make it modular as well so there is plenty of flexibility in the design.
There are many options for assembly:

The base can be made out of wood or you can use 8020 aluminum profiles. A wooden base would save a bit on the cost, if you have the tools to make it strong.


The Y axis can use single or dual smooth rods, dual rods will help reduce deflection and rotation in the X direction but it adds a bit of height and some more expense.


There are optional standoffs for the stepper motors that when combined with a longer lead screw and a pair of bearings can be used to tension the lead screw to add support and reduce whip along with helping reduce the load on the stepper motor bearings.


The size can easily be adjusted up or down by increasing or shrinking the length of the rods and lead screws. A larger build volume is always nice but there is a linear relationship between build volume and flex (smaller build volume is more solid).

You can use any controller and stepper drivers however I am using a low cost CNC shield on an Arduino UNO with GRBL v1.1j and TMC2208 drivers to reduce the noise. Going with DRV8825 or A4988 would probably better if your focus is on machining wood. I highly recommend fitting a cooling fan to the drivers, they can handle a lot more current with active cooling than without.
Materials:
2 600 mm x 12 mm smooth rods for y axis
2 400 mm x 12 mm smooth rods for the x axis
2 200 mm)x 12 mm smooth rods for the z axis
2 600 mm x 8 mm 8 mm lead (2 mm pitch, 4 starts) lead screw for the y axis
1 450 mm x 8 mm, 8 mm lead (2 mm pitch, 4 starts) lead screw for the x axis
1 200 mm x 8 mm, 8 mm lead (2 mm pitch, 4 starts) lead screw for the z axis
6 LM12LUU linear bearings
4 48 mm Nema 17 stepper motors, 2 A, 1.8 degree step
8 608ZZ skateboard bearings to help support the lead screws
1 UNO + CNC Shield + 4 TMC2208 drivers to control the stepper motors
1 24v 3A power supply for the CNC shield
1 500 W spindle, if you want to machine wood
26 M5 x 12 mm hex cap screws
100 M3 x 12 mm hex cap screws
Optional 8020 base frame:
2 600 mm 8020 aluminum extrusions
5 400 mm 8020 aluminum extrusions
56 M5 x 12 mm hex cap screws
56 M5 T-nuts
Misc optional:
4 8 mm to 5 mm aluminum couplers to attach the steppers to the lead screws. A model for a 3D printed clamp is provided as an alternative
4 8 mm anti backlash nuts to reduce play on the lead screws. The nuts that come with the lead screws work just fine, but this can tighten things up and reduce a small bit of backlash
2 600 mm x 12 mm smooth rods for y axis, this doubles the number of smooth rods on the y axis
2 LM12LUU linear bearings for the y axis to go with the smooth rods
Fusion 360 Files:
clamp 8MM https://a360.co/3j9rC2Q
control box https://a360.co/3j6oa92
corner bracket 25 mm https://a360.co/3laRGME
corner bracket 40 mm https://a360.co/32izrwj
coupler 5 mm to 8 mm https://a360.co/2YuzyUd
rail clamp https://a360.co/3hpC3if
spindle controller left https://a360.co/3hpgtKI
spindle controler right https://a360.co/2YrdMRt
x carriage https://a360.co/2EcwAgt
y carriage https://a360.co/3grzB9s
y clamp https://a360.co/3l5Tvue
servo standoff https://a360.co/3gjJbuZ
Y Dual Rod:
y carriage dual axis https://a360.co/2YveNHY
y clamp dual axis https://a360.co/3gw9kHn
Z Carriage Version 1:
drag knife holder https://a360.co/3hpgGO0
pen holder https://a360.co/31oy8fK
z carriage https://a360.co/2Qj6aMf
z carriage motor https://a360.co/3j9EaHq
Z Carriage Version 2:
pen holder v2 https://a360.co/34ssBGY
z carriage v2 https://a360.co/2YoQRpK
z carriage v2 motor clamp https://a360.co/2CSk2Ki
Printer settings
Print with PLA at 20% infill 0.4 mm line width, 0.2 mm layer height, 1.2 mm wall thickness and 1.0 mm top/bottom thickness. All parts are oriented for optimal printing already. And all are designed to print without a brim, raft, or support.
Change List
2020/08/24, re-exported the files to correct some issues.
2020/08/25, finalized v2 clamp system