best edge quality for cut aluminum

Hi all

whats the best method for cutting aluminum plate and getting a clean edge. I've tried water jet but the edge looks sand blasted (because it kind is) .
Saw some examples of a laser but the edge was rough with slag on bottom edge, bad laser cut??

Had some stainless cut on laser and the edge is great(see image..top is stainless bottom is aluminum water jet)

what about plasma cutting?
CNC router looks nice but some of my parts are small with lots of detail ...hold down might be a problem

thanks
Ter.

I'll admit the stainless looks pretty good for laser cut. Your laser house must have primo equipment and know what they are doing. For aluminum however, I doubt you will be able to achieve it. If you really need the surface finish you will probably have to waterjet a little bit bigger size and set up a sacrificial plate fixture and buzz around the profile with an endmill. One thing you could try is to set up a drum sander with a non-woven unitized abrasive wheel like Norton makes. You can get them as wheels or spindle mounted styles in many different blending and polishing grits.

They are a bit pricey, but we use them to take the tabs and burs off of aluminum parts off the waterjet and they can produce a pretty amazing finish just by freehanding.

If quantity justified, it would be straightforward to make a pressure plate fixture for your Al parts, to hold the parts down for cleaning up in a VMC. The pressure plate has the same cutouts as your part + .02" or so, and this plate holds the part down on a fixture that has some holes out at the periphery strategically placed to allow removable pins to locate the blank accurately.

Don't know what you're paying for waterjet, but the pictured part might actually be cheaper milled straightaway. First pass does all the inside work on a square piece of stock, then a pressure plate fixture to finish the outside. They would come out of the machine with shiny edges, and edge breaks .

Regards.

Mike