Hi all,
I am looking to build my first CNC router/mill, and am looking for some general thoughts!
My machine needs to be quite large, with a cutting area around 3-4ft x 4-5ft. For the most part it will be cutting reasonably soft materials (I'm actually building the machine to cut prototype bodypanels and plugs from foam for a car I'm designing) however I'd also like it to be able to cut softish ally in smaller parts as well. Realistically 3ft x 5ft isn't quite large enough, but I can do some panels in 2 parts and join them on the chassis, but I'd obviously like to keep this to a minimum
Going on the above I dont really want to build it from MDF, but was looking at Aluminium extrusions. I have a large crosscut saw which runs on an ally "I" beam and was considering making the 2 longer sides in a similar way, with the bearings clamping around the top of each "I". I would then use 2 further I beams to create the end panels, and weld some triangulation in for extra rigidity. How's it sound so far? over the top or not beefy enough?!
Next problem is drive. I have all the electronics and motors (shafts are a bit smaller than I'd have liked so I might swap those out) but I need to transfer that to the various axis. I've been told that for the majority of this kind of work screw threads such as these threaded spindles with some home made anti-backlash nuts. I'm thinking though that at 5ft long I'm either going to need a rediculously over-size diameter or some sort of additional support?
Any and all thoughts and suggestions much appreciated.