A simple and tough cnc frame made from low cost hardware store parts and affordable electronics
Two meters worth of 30x30mm tube has been hacksawed to four equal length parts. A 20cm long and 50x50mm wide sled is on top for reference. Maybe the sled length could be reduced, let's see. Below is a picture of the big brother of the Peoples CNC Machine.
I've ordered some SC8UU bushing blocks and mounts for 8mm pipe for the Z-axis. I'm also looking for well priced lead screw sets to move the drill plate. The sideways work area was reduced because the pipe guides are far apart from each other. I think its a necessary sacrifice, it also allowed me to flip the lower central sled up to reduce the height of the gantry. Thanks to everyone following the project, it's encouraging to see that there is interest in such an apparatus!
I've started with 30x30mm rails and 50x50mm sleds. The sleds allow for M8 screw ends to fit inside the square tube nicely. All the rails are 500mm long. The sleds might be too short or I could place the wheels closer to the their edges to prevent rocking. Maybe the 2 on top 1 on bottom wheel arrangement isn't stable enough, if it isn't, more wheels are in order. These are sketches not the final design, the design will transform as the project moves along.
At the Jyväskylä Hacklab here in Finland we've been building a large CNC machine for some months. The inspiration for the Peoples CNC Frame (PCF) comes from the successes and lessons that our lab machine has taught us. The elegance of the PCF comes from its simplicity, ruggedness and availability of parts and tools. Linear motion on the X and Y axis is achieved by using skateboard wheels and bearings. These can be ordered online for quite cheap. The rails are standard hardware store square pipe. Our hacklab version is based on 50x50mm rails, it uses lead screws and covers an area of 1x1m (cutting area is less). The machine is very sturdy and could easily be much larger without losing rigidity. Our hacklab version uses longboard wheels.
The People need a CNC machine for home. I often have a need to engrave a PCB quickly to test a circuit and I wish I had a CNC machine to do the job. I'm sure you have a need for a desktop CNC machine as well, so heck lets make one.
I've ordered some standard skateboard wheels and bearings. While I wait for them I'm going make a sketch of how the Peoples CNC Frame could look like, it'll be smaller than our hacklab version since we don't want to upset our partners, neighbors, pets or our personal zen.