Originally Posted by
Ivan-Ivanov
Hi All
I'd like to build a metalworking CNC router for materials such as: hard and mild steels, high-quality steels, stainless steels, and others of the sort. The easiest route for me is to build the machine out of bosch rexroth aluminum profiles, but I'm worried about flexing and vibrations.
My question is: before I throw the effort to research and calculate the base, gantry etc..., is it at all possible to have a dissent metalworking CNC router built out of aluminum profiles?
the work volume is 500x400x250mm, while the machine dimensions would be in order of 1500x1500x1500mm (large spacings between bearings to mitigate the moments created by the cutting action). I'll work steel plates no thicker than 15mm. I'll use end mills of 8mm max. I'll use 6.5kW spindle.
4mm and 6mm end mills would be the typical tools, the 8mm and 10mm end mills would be for facing operations only, not deeper than 0.5-1mm.
If I use beefy 80x80mm rexroth profiles and 80x160mm in more critical areas; If I maximize the distance between the linear bearings to 1.5 or even 2 times the z axis travel or more, and put intermediate bearings, or even additional rails/bearings per side would that mitigate the fact that I use aluminum profiles.
I plan to build a really beefy base, gantry and plunger, with many cross beams and reinforcing beams where possible. My budget is quite large...
Also I don't pursue fast and efficient process. Having the machine work for 6-8 hours on a piece is fine with me. (I mean the machine would not endure the thick chip load, professional machines usually do).
I'm going to put two pre-loaded nuts per screw to get rid of back-lash, also tightened linear bearings, and pre-loaded cone-ball bearings for the screws.
I also consider the possibility of building the machine out of reinforced foam-concrete. I heard it has great vibration dampening properties. But that is considerably more difficult option for me.
Thanks a lot, in advance.