CNC Build #2. Mechanical Build
The first thing with a design like this is to produce a model so you know what you’re building, DS Mechanical is a perfect candidate to do this and this is the design I came up with.
It is 1500mm x 1500mm nominally and parts where sourced from many different suppliers. Fundamentally this is an OpenBuilds style CNC router and is built around the V Rail T Slot extrusions, the profile looks like this:-
The above diagram shows a 20x20, 40x20, 60x20 and finally an 80x20, they are available in many lengths and as I wanted to be able to use a half sheet of plywood for the work area (4'x4') I went with 1500mm long extrusions. These are all based on a metric system and are precision made so there able to be the bearing surfaces for wheel based linear motion.
I chose to use what are called extreme wheels to add life and accuracy to the solution, here is one being mounted onto an X gantry plate.
Pretty much all of the parts are designed to follow a 10mm grid so they will fit together with minimal fuss.
The basic frame is pretty obvious from the pictures above but for additional detail, here are closer views of the Y gantry plate construction.
And the X plate construction, my extrusion is much longer (12") than the design (6" maybe?)
The clamp shown holding the router is a temporary measure, I have now designed and printed another one more suitable, it took about 25Hrs to actually print. I used 8 layer walls and a 50% fill to give it plenty of strength and I also added fixture holes and increased the height to 40mm which is the combined height of the two being used in the above picture. I will take you through the design of the mount in a separate video, for now here is what the new design mount looks like in DS Mechanical tool... much nicer
You can buy these mounts separately if you want and they run about $30 or more but you have to ensure it is suitable for your router and design. As I had a 3D printer I chose to roll my own in PLA.
Without further delay, here is the video of the frame build