How to face aluminum plate stock?

[Birdpath]

Hi folks: complete beginner here. I have a bridgeport 2J mill I am enjoying learning to use. I am using aluminum stock to make jigs in tandem with 8020 extrusion. I have some 3/4" aluminum plate ranging from 6 x 10" to 4 x 12". The face of some pieces has scratches and shallow dings. For my smaller pieces of bar stock, I have been using my largest end mill (2 flute 3/4 diameter) to square them up. To face these smaller pieces, I have just been running the end mill back and forth, making multiple passes. Probably not the best procedure, but better than the belt sander I might have used previously.

I have been reading about fly cutters (cheaper, may harm bearings, better finish, larger working area, slower) and face mills (increased expense, smaller, harder to set up, take off more stock).

If I were a novice in your shop and wanted to just clean up the surface/face of some larger pieces of aluminum, how would you tell me to do it? I don't have to do it in just one pass; within reason more $ is okay if it is a tool I can use for a while to come.

Thanks for any input! Daniel

 

[wawoodman]

I would say fly cutter, for the very reasons you mentioned (except I've never heard of them damaging bearings.)

 

[Dave Paine]

Fly cutters work. I think most milling machines can handle the load without issues.

I do not yet have a fly cutter so have been making many passes with my 1in end mill when I have to clean a surface.

I have been looking at indexable end mills. Not expensive and a more balanced load on the mill. An example of a 2in RB shank from Shars. Many versions on the market. Look at the cost of the inserts before you decide.

http://www.shars.com/r8-shank-2-carbide-indexable-end-mill

 

[mikey]

I have a bridgeport 2J mill I am enjoying learning to use.

I have been reading about fly cutters (cheaper, may harm bearings, better finish, larger working area, slower) and face mills (increased expense, smaller, harder to set up, take off more stock).

If I were a novice in your shop and wanted to just clean up the surface/face of some larger pieces of aluminum, how would you tell me to do it? I don't have to do it in just one pass; within reason more $ is okay if it is a tool I can use for a while to come.

Daniel, I agree with Mike and Dave - a fly cutter is the right tool for this job. It will give you a very flat surface quickly and that surface will not have the multiple tracks and end mill leaves. Finish is very good (near mirror finish) and modern inserted tip fly cutters can do pretty impressive stock removal. Fly cutters also cut with only one or sometimes two cutting edges; this requires far less horsepower than a fully decked out face mill needs. A typical fly cutter can cut a swath 2 - 6" in diameter; imagine the power a 6" face mill would require.

Almost all projects you do on the mill will require surface prep and squaring before you start working the piece. A fly cutter will serve you well for this job. Have a look at the Tormach Superfly, the Suburban fly cutter and the B-52. I only have experience with the Superfly and can recommend it.

 

[kd4gij]

Both work well. If you have a lathe a fly cutter would be a fun easy project to make.

 

[Birdpath]

You guys are great !!! Thanks for the informative, specific suggestions to help me on my way. Love this forum. Wish me luck. Daniel