[didado]

Can I ask a question to the fellow BF20 or similar owners? Hoss what kind of results do you get with side milling? when I use any size 2 flute end mill on Alum or brass or mild steel I get wavey results... Is this a limitation to the machine? or can you recomend some things to try to get rid of this?

I have both the BF30 (not the Optimum BF30 but Weis-like BF-30) and the BF20. I've had the BF20 since 2005. (they've been around here in Europe for quite some time) The results you're talking about are normal.

Like Hoss said use a four flute for side millling. Generally I take the side cut and then leave the settings as is and reverse ( not the spindle) the cut so it does a finishing climb milling cut. You'll notice that the cutter has deflected during your first cut because it takes off another couple of hundreds of mm when you move the bed back. Even if you run the cutter back and forth several times side cutting with the same setting it keeps cutting a tiny bit because of deflection. This is not necessarily the result of the machine but for a large part caused by the deflection of the cutter itself. The result is often much better. I also use this trick when I really need accurate dimensions and I'm off some hundreds of mm. Generally, I also use the biggest diameter cutter that fits in my machine for sidecutting. The bigger the cutter, the more rigid it is.

On Aluminum you want flood or at least a generous amount of WD40 to get a relative smooth side cutting finish. Aluminum is sticky and tends to stick to the flutes and get in the way while cutting, resulting in a poor finish. Blowing the chips with air is also a great help. Don't however, expect the finish you get with flycutting. It's going to be somewhat wavy. Just except it to a degree.

David