1/2" end mill vs. 1/2" core box bit

[Chuck Keysor]

Hello Shopbot experts/helpful friends:

Can anyone tell me if there is any advantage to using a 1/2" core box bit (two straight cutters) versus a 1/2" ball nose end mill with two spiral flutes for 3d finishing? (I'm using Aspire.)

I will be doing 3d finishing of a couple of wooden (pine) house decorations that are about 2 feet by 1 foot. (I'm using a 1/2" flat end mill for the 3d roughing.)

I have only done 3d cutting on one project, (maybe 5 3d parts were involved) and I had used a core box cutter and it seemed to work fine. But that project had long straight sections, and this project has lots of curves.

I don't want to just go ahead and buy the more expensive (about double) ball nose end mill without first getting a recommendation that it will do anything better than the core box bit.

Are there any differences in the speeds and feeds between these types of cutters? What would the ball park speeds and feeds be for each type?

Thank you, Chuck

[Brady Watson]

The ball end mill will result in a smoother finish since most core box bits are split right at the tip. However, since you are machining pine, it probably won't matter either way.

Invest in good tooling. It makes a difference. For pine it won't matter - but when you get some nice lumber and want to show it off, it's worth it. Besides, that solid carbide ball will outlast that core box bit by a factor of at least 3X. Buy tools on value, not price.

-B

[Chuck Keysor]

Thank you Brady. I appreciate your assistance and willingness to offer your time and insight. I do have another project coming where appearance will be more critical, so I'll probably buy the ball nose end mill. Thanks again, Chuck