trouble cutting Baltic Birch

[carguy327]

Hello All,

I'm milling out some panels out of baltic birch and it's looking pretty bad. I'm using a relatively new 4 flute up spiral 0.5" Tialn coated bit. I'm getting fuzzy edges and very bad chipping when cutting across the grain. Should I be using a straight flute?
Any other suggestions? Feeds ( mechanical holdowns ) speeds?

Gerald
www.imperium-design.com

[ger21]

Use a spiral bit for wood, not metal. If the material is thick enough, use a compression spiral. That's the only way to not get fuzzy edges. Depending on the thickness, with a carbide spiral for wood, try 15,000 rpm and 150ipm.

[carguy327]

Use a spiral bit for wood, not metal.

I didn't realize that there's a difference. What is the difference?

My feed/speed seem to be close at 130/16000

Since my first post, I went and bought a couple new bits. They are certainly meant for metal. A little better but still alot of chipping.

Cheers,

Gerald

[ger21]

If you only need one face clean, either use a downcut spiral face up, or an upcut spiral face down. If you need both, use a compression spiral. Plywood is very hard on bits. Keep them clean if you see buildup forming on them, and go as fast as you can to maximize tool life, but not at the expense of cut quality. Generally, with wood, go as fast as you can and still get an acceptable quality cut. Faster is better for tool life, but too fast is bad for cut quality. Provided you have enough HP to go really fast.

The difference between wood and metal bits is the cutting geometries. The cutting edges on wood bits can be thinner and slice better, because they don't need the durability you'd need cutting metal. Wood bits also can have larger flutes to remove the material at the much faster rates. Another difference, and a big one, is that wood spiral bits are much more expensive than metal cutting endmills.

Check out some of these. http://www.amanatool.com/spiralbits.html

If this is for a commercial application, I'd recommend www.vortextool.com They are the only bits we use. They give a 30% price break when you buy 3 or 4 1/2" bits, or 6-7 1/4" bits.

If you're not cutting a lot of this , you can get decent results with very sharp (new) carbide tipped straight router bits. But they will give fuzzing when cutting across the grain, but it can be easily sanded out. You shouldn't be getting chipping at all.

[carguy327]

Thanks Gerry,

Great info,

Gerald