My Belt & Pinion Drive CNC Router

I have wanted to build my own CNC Router for quite awhile, and when I discovered OpenBuilds i decided to finally pull the trigger and see what I could come up with. I was very familiar with Arduino from my previous projects so I decided to employ GRBL for my G code interpreter as it seemed straightforward and easy to get started with. After looking around at other CNC builds, I decided to use the Routy CNC project as a basis for the design because i liked the idea of it's belt and pinion drive system over traditional machines that employ lead-screw or ball-screw driven axes. Kudos to Mark Carew for posting the Routy and inspiring me to finally build my own machine...

I have tried to document the progress of my build as best as possible and will share below a (somewhat) chronological progression of the construction thus far. I am finished with the mechanical portion of the build and am now working on the electronics wiring and testing, etc. I will continue to update this build and get things as organized as possible so that my pictures may serve as a reference for anyone wanting to replicate or modify a portion of my machine. I am currently compiling a detailed parts list, all of which are available from openbuildspartstore.com, and I will post it as soon as it is complete

XY Sub-Frame

The lower frame is entirely constructed from 20x80 V-Slot railing, with the Y-axis gantry support rails being made of 20x60 V-Slot railing. There are...

(2) 710mm 20x80 V-Slot Rails
(2) 400mm 20x80 V-Slot Rails
(2) 750mm 20x60 V-Slot Rails

The 710mm rails are inset 9cm from the edge of the 400mm rail, just as in the construction of the Routy CNC; this allows for the Y axis stepper motors to travel underneath the spoil board and be hidden from view during operation. They are all secured together using...

(8) 90° Double L-Brackets
(4) Cast Corner Brackets
(4) 3 Hole Joining Strip Plates
(44) Tee Nuts
(32) 8mm M5 Low Profile Screws
(12) 10mm M5 Low Profile Screws

Y Axis Gantry Plates


The Y axis gantry plates and belt and pinion drive train is exactly the same assembly as in the Routy CNC project. I realized afterward that I didn't take as many photos of this assembly process as I probably should have. However, the Routy page has a large amount of pictures that show in more detail the placing of the wheels, shims, spacers, etc., they were an enormous help to me in understanding the general assembly process and if you choose to build this machine i highly recommend taking a look at them.

Attaching & Squaring Gantry Frame

I opted to use 20x60 V-Slot railing for the vertical gantry arms rather than 20x40 for additional rigidity. I also extended their lengths to allow for raising the XZ axis assembly for odd or thicker than usual work pieces like ABS project boxes or any other overly thick items. I used a digital angle gauge, and a set of 1-2-3 machinist blocks to level and square the XZ axis crossmember, as well as to accurately space the lower mounted rail for electronics mounting. Just to note, the upper XZ axis crossmember is 418 mm in length, and the lower electronics mounting railing is 458 mm in length ( both 20x60 V-Slot )

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