The more I read the more I learned to a point of information overload. I will build either a 4x4 or 4x8 Cnc. Mostly will be cutting MDF, melamine should I go Linear rail or belt. Not a fan of belts but will a 8 foot lead screw or linear flex in the middle ? If you build one Your experience would be very helpful Thank you
Belts are fine for cutting soft materials. The key is properly sizing the belt. For that kind of length I probably would not go less than a 15mm belt. Rack and pinion is a better option but is often well beyond the budget.
Rack and pinion is like rails and screws. Cheap to import directly up to 1500mm, then gets really expensive. Upside of rack is that you can cut or print an alignment tool to put two pieces together. Not so much with belt or screw. 4x4 is the way to go if you don't need the full sheet capability (though doubling machine size later on with these kinds of machines isn't really a big deal).
Ok that makes sense 1500 is just shy of 5 feet .I could drop 1/2 a sheet of MDF Rack and pinion Definitely spindle I want this machine to be entry level light commercial. Stepper motors, Use common one ?
You're probably gonna have to define what you mean by light commercial, because you can buy a 4x8 light commercial router direct from China for like, $5k. They're not expensive at all, because they're produced in such colossal volume. The same machine from Laguna or wherever is gonna be like $25k to account for import, storage, QC, warranty, support, etc etc. Light commercial typically means something along the lines of: 3-5kW spindle NEMA 34 4-8Nm Closed-loop steppers or servos driving axes 1/8-1/4" steel frame 15-20mm linear rail Mach 3/4 or LinuxCNC control Etc. Something you're gonna find in a cabinet shop, prop shop, or other prototyping or light manufacturing facility. You may find what you actually mean is more like "high-end hobbyist", especially if you're planning on using much extrusion (ie. V-Slot or T-Slot). I'm planning such a machine right now- starts out as high-end hobbyist, with the option to later convert into light commercial when I move somewhere more appropriate (ie. not a basement). That's more along the lines of: 1.5-3kW spindle 2Nm NEMA23 to 5Nm NEMA 34 open- or closed-loop steppers Aluminum mill-stock and extrusion frame 15-20mm linear rail Grbl, Mach 3/4, or LinuxCNC control Etc. I'm doing screws at 1500mm, personally, because I want to keep aluminum cutting and maybe some light steel on the table. Rack and pinion you really lose that because you're relying directly on motor torque. It's more for wood, plastic and foam. Entry-level hobbyist, by contrast, would be like what OpenBuilds offer off-the-shelf- wheels, router, etc. Good for dipping a toe in to learn, and can definitely make some good stuff, but is gonna struggle with any kind of meaningful daily volume.
If you seek light commercial buy light commercial. Attempting to morph hobby grade systems into commercial use is a recipe for disappointment (and at OpenBuilds we do our best to prevent users from setting themselves up for disappointment). Sure you can make money with hobby grade systems, it typically doesn't make for a good business model.
Some very valuable info guys thank You. Ok so my needs are definitely high end hobbyists Mostly right now making arcades, epoxy poor and Canadian military plaques and endless NHL stuff. I want to stay away from belts. I currently have. 800x1000 belt driven and I’m happy ish with it. Ok I will read more on stepper motor and frame thickness.. I’m sure it will generate more questions.
