What would it take to make a gantry router/mill

[LessPaul]

I am thinking about putting together an 80/20 based router. Though the majority of what I would do would be wood, there are times when I'd like to be able to work with metal.

I am planning a Bosch Colt for the router, but I understand its RPMs are far too high. I also doubt the bearings etc would stand the stress of cutting metal, but this is only a hunch. If you know otherwise, please correct me!

As a bit of a newbie, I don't know a lot about what it would take to accomplish this task. Would I be better off with a moving table? Would modifying the Bosch to give it lower speeds be an option? What about interchangeable spindles?

I'm curious what others have learned, both good and bad. Thanks much! Paul

[jalessi]

Aluminum can be milled with ease at 16,000 rpm, see attached video.

"http://www.youtube.com/watch?v=p5uHu09vyZo"]YouTube- T2CNC - V3.0 - Lady Alu Milling

Welcome to the Zone,

Jeff...

[DIYaholic]

LessPaul,
I don't know anything about the Bosch Colt, so I will leave that question for others to answer. I do believe though, there are specialty bits designed for routing aluminium at higher speeds.
As for the moving table design question. For milling aluminium, you want rigidity. A properly designed & built, moving table machine lends itself to a much more ridgid machine. The catch is "Properly Designed & Built"!!! A superiorly designed & built moving gantry machine will out perform a poorly designed & built moving table machine.

Randy,

[stevespo]

Aluminum can be milled with ease at 16,000 rpm, see attached video.

As DIYaholic mentioned, it's going to depend on the rigidity or the machine, the quality of the build components, etc. The machine in the video looks like a commercial unit with very nice components. Heavy, solid AL, quality linear rails, perhaps even ground ballscrews, etc. The spindle alone costs more than many of us spent on our entire machines.

So, I do agree that aluminum can be milled at high RPMs with proper tooling and feed rates (I do it occasionally). However, the results will depend largely on the design of the machine, quality of the spindle, etc, etc. There are many nice 8020 examples on the CNCzone, some of which are used for heavy duty work in a variety of materials.

IMO, the Colt is a nice, light duty router (maybe somewhat closer to a laminate trimmer). I wouldn't expect it to hold up all that well cutting aluminum. Even on a CNC, dedicated to wood cutting, it's lifespan is going to be shortened due to the long duty cycles, potentially faster feedrates, etc. Many people are unhappy with the short life of their 1617 series routers when mounted on a CNC, and those are larger, much more powerful routers.

It will work, but keep your expectations reasonable.

Steve My own 8020 build

[LazyMan]

This guys diy machine seems to cut aluminum quite nice

"http://www.youtube.com/watch?v=KioGEEqIXu8&feature=related"]YouTube- Aluminium work