anyone using spiral bits?

[betacrash]

Is anyone using 1/8" and/or 3/8" spiral bits as an alternative to the straight cutting and straight - jointing bits? Im thinking about getting a couple from pricecutters.com and just wanted to know anyone elses experiences. I guess I would go with down spiral.

[pkunk]

They'll work fine within the parameters of less cutting depth. Use the upcut spiral though.

[betacrash]

what is the reason for recommending the upcut instead of down? thanks -shawn

[edzbaker]

Shawn, the Machine does cutouts in several passes, with each pass a little deeper than the previous one, and raising the bit at specific intervals to leave the tabs. If you used a DownCut bit, the bit would try to force the chips against the bottom of the cut, instead of out the top of the cut.

[John]

It is better to use down cut spirals. They are commonly used on large cnc routers for two reasons. They do not lift the work off the spoil board like upcut spirals do, and they avoid the tear out problem on the top surface. Cnc 's where the operator has full control will have a downcut spiral ramp into the work. The CW takes such shallow cuts on each pass it is not necessary, although when cutting an oval or circle the CW firmware does ramp into the cut. The only time I would use an upcut is when I am drilling holes the same size as the bit to a significant depth.