If you are designing an extremely high quality CNC router specifically to be mass produced and sold to others, consider cast iron for your frame. There is significant upfront engineering cost to produce the required molds, but once you have molds the per-unit cost of casting can be cost competitive. The casting process does not leave you with precision surfaces, so surface machining will be required on any parts that must be within a specified tolerance.
Cast parts generally need to be sand blasted and painted to survive industrial environments. Other disadvantages are that cast iron parts can easily rust in open air or corrode if attacked with solvents. It is prohibitively expensive and difficult for most hobbyists, but it produces some of the finest CNC machines that can be produced. This technique requires a tremendous amount of pre-planning, experience, and access to a metal foundry. Mills and lathes very often have frames made of cast iron for its superior vibration damping, extreme rigidity, and reduced part count by combining many parts together into a single casting. Still, it is a very popular choice because it is the cheapest, easiest way to produce a machine capable of hitting tolerances and producing great surface finishes. The main disadvantages of 8020 are that it is more costly than extruded aluminum tube and that it isn't as rigid as steel. Some providers can even mill precision surfaces onto your extrusion, allowing it to play double duty as a structural member and a linear guide. The main advantages are that you get the rigidity of metal-on-metal joints and the infinite reworkability of a lego set without the difficulty of more traditional metalworking. If you have a miter saw you can easily cut it to length yourself to produce whatever design you like. The ease of working with 8020 cannot be overstated. The extruded profiles can be ordered in many dimensions and some providers like Misumi will not only cut them to length for you, they will drill and countersink holes, they will tap ends, and perform many other operations for you right in their factory. Extruded Aluminum aka 8020Ī very popular choice for router frames is aluminum 8020. If you are a woodworker used to table saws and pencil-drawn lines, tolerances that tight are fantastic and either a wooden frame or mostly printed frame will likely exceed your needs. I should mention that "low-precision" for a CNC router might mean give or take 30 thousandths of an inch. This limits the usefulness to hobby and art projects.
Extruded metal is not a precision surface so any surface imperfections in the metal will translate to imperfections in the finished work. Another common weakness in these designs is to use the extruded metal surface as the linear guide. Their primary weakness is that 3D printed parts aren't very rigid, so the precision, repeatability, and surface finish of parts created on these machines is limited. Given the ubiquity of 3D printers nowadays, these designs are extremely accessible, maybe moreso than wooden designs.
Many of these designs don't require metalworking skills of any kind except to cut metal tubes to length. The Mostly Printed CNC and others like it make use of cheap extruded metal tube to serve as bones and 3D printed parts to serve as joints. You should use the most rigid material you are able to work with. The frame is the main body of your machine.
#Craigslist desktop cnc router generator
Those motors are controlled by a pulse generator attached to a gcode intepreter, which gets its commands from a gcode sender.
You actuate that movement with belts or screws, whose rotation is powered by motors. On top of the frame you attach linear guides which allow your axes to move. The foundation of a CNC router is some sort of rigid frame.
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