This is just a short intro as to how I went about building CNC plotter. most of this is built using old printer and scanner parts or parts that can be easily found at a hardware store.If I left anything out just leave a comment. I built this for my final year project in college and looking back i really should have documented a lot more.
All of the code is available on my GitHub (username: brsc2909) as well as well as the files for manufacturing the pcb. as well as a more detailed report which you can download. you could build this on breadboard or strip board but a PCB is prettier. I'd love to see somebody build on this and turn it into a fully fledged CNC or 3d printer.
Step 1: Building the Actual Machine (the Hard Hardware)
I'm not a mechanical engineer so if your slightly squeamish look away now... there are better ways to build a cnc machine and this is probably a shoddy attempt at best but with a BOM of under 50 euro and being made from parts and scrap its not actually that bad.
the main frame:
this is made out of 1" steel box section, I created a jig with screws on a piece of plywood to hold everything in place while welding and it actually worked pretty well. I made the frame in two "H" sections first and then joined them together.
Step 2: X-axis
the x axis runs on drawer sliders and consists of a crude "H" section made out of 1x1 1/2 " timber. a 10mm layer of mdf creates a bed or base to draw on .i later added another layer of mdf with a hardened Formica top and used a bolt at each corner to level the bed. the pulley system was taken from a office laser printer that I mcGuyver'd together
the thread on all the axis's is M8*1.25mm so one revolution of the stepper motor moves the axis 1.25mm. couple this with 200 steps per revolution gives us 1.25/200 = 0.00625mm per step.
Step 3: The Z-axis
the most annoying part of the build for me anyways. as this was a "build with what i can get my hands on" type build it took quit a lot of reworking and re-do's to get this right. basically its a square in the middle that runs up and down the frame on roller blade bearing. a M8 nut fitted to middle on either side and two threaded bars connected to a stepper motor at the top of the machine provides the movement. the y-axis is also housed in this unit. in the end it proved to be steady and worked quit well.
Step 4: Y-axis
the pictures here can describe more than i can. i used rep-reap style timing belt to couple the motors with the threaded bar as well as rep-rap style pulleys.
Step 5: Intel Galileo Cnc Shield Controller
it would take me a week to explain every detail of this so i will include the schematic here. I made a pcb but you don't have to.
note: this will also work with an arduino but there are already better more complete arduino solutions out there.
Step 6: Galileo Cnc Windows Application + Controller Software
like the controller board i wont go through each detail but by all means if you have a question leave a comment. the
windows application is written in c and the the controller software is written in a mixture of arduino and c. you can get the code on my GitHub galileo-cnc . I would also advise you to have a look at the project report for more details. hope i have educated at least some of you and hope so see somebody repeat this and hopefully make it better.