I just posted on Github my design files and documentation for the new CNC router I completed it in December. It took me a while to get the model cleaned up, and all the documentation in order so it matched my As-Built final assembly. Model files were natively designed in Solidworks 2018, but I also exported and converted into many other 3D formats (Fusion360, Step, Iges, X_T, 3d-pdf). I also generated dimensioned prints for all fabricated parts and exploded view assemblies (pdf, dxf, and dwg).
I have included a detailed BOM and all documentation and manuals I utilized are uploaded as well. Pretty much everything is modeled in, down to every bolt, washer, etc. Hopefully these files and documentation can be useful to others in their projects.
Incredible detail in the Fusion file. I’m thinking of upgrading my MPCNC frame and belt system. Reusing all the servos, drivers, controller, computer, wiring. Add linear rails and ball screws which are shockingly cost effective compared to aluminum extrusion.
Been pricing out all that 1000mm extrusion and it’s crazy expensive. Cheapest I could find a 80 x 120 x 1000 gantry bridge was just over $200 with shipping. A large corporate like Grainger wants $500+ which is insane for 25 lbs of aluminum. It’s priced like gold or platinum precious metal. The rest of the 40 x 120 and 40 x 80 would be maybe another $800. So maybe $1000-$1200 for the bottom frame extrusion total. Which seems like A LOT for just the material of a machine frame; essentially the material of a small utility table WITHOUT LEGS. Considering a fine woodworking table piece the same size with mixed exotic woods, drawers and inlays from a custom builder would be less. I could use my MPCNC to cut the aluminum gantry sides and source the 13mm sheet locally for maybe $500.
All in for the frame upgrade is maybe $1600 to $2000 which seems like a lot for just structural elements. Adding 1000mm ball screw and linear track rails would only be another $400.
Why is Aluminum extrusion so expensive? Is it the tariffs? Seems like DOUBLE what it should be. Why is the stuff not made locally in the USA? Aluminum is the most abundant metal on the Earth’s surface and more abundant than iron by 1.6x by weight.
I’m just not sure if it’s worth it for the rigidity upgrade. The aluminum extrusion is really expensive, way more than I would’ve imagined.
I suppose I could reengineer the lower frame and forgo the convenience of T slot extrusion for steel box section. 3D print joints and rail interfaces bolt and epoxy everything together. Then I have to drill and tap dozens of holes for the linear rails. ASA-GF is dimensionally stable, stiff, and inexpensive in 3kg bulk. I wouldn’t try to weld up a lower frame with all the heat distortion and my cheapo stick welder, and then try to flame straighten it back. I’d chase my tail for days and end up with a potato chip frame. I’d need a giant flat welding table that I don’t have.
Maybe keep the gantry bridge and tower design in aluminum because of the weight savings. Maybe redo the side towers in ASA-GF and epoxy steel plate in instead of the aluminum plate. Would be about 1kg of ASA-GF and some extra time cutting steel and mixing epoxy, but it’d probably be just as stiff, just more bulky. Could use my MPCNC to pilot drill the holes in steel plate, then finish off with a hand drill and cut with a grinder, then epoxy it in and conceal it with a plastic vanity cover.
I guess I was thinking to upgrade from belt drives to ball screws and linear rails would be a HUGE upgrade. But then to see the prices to upgrade the frame and gantry as and additional 4x to 5x ON TOP of the screws and rails seems insane to me.
ans: Aluminum is expensive in the US today due to increased U.S. import tariffs on foreign aluminum, which raise the cost of the metal, and the shortage of competitively priced electricity needed for domestic aluminum production, making it difficult to meet demand. High shipping costs, port congestion, and reduced domestic production capacity due to smelter closures further contribute to higher prices for American consumers and businesses.
I just checked my usual (German) supplier, and the price per meter for this is around $130, not including shipping (which is usually around $30). So it does look as if the US price is somewhat higher than the European one.
