Router bit question

[Randy Rose]

Forgive my ignorance but, can I expect less end grain tear-out and burning with a spiral up-cut bit (1/4 or 3/8ths dia.) when cutting circles than when using a straight fluted bit ?

Have an upcoming project requiring multiple circles 6" to 8" in diameter X 1.5" thick. ( NO, I`m not trying to do this cut in one pass)
Material will vary between poplar/B.Birch ply/maple/walnut.

( FWIW, most of my current cutters are Freud and Whiteside)

Thank you for your input.

[Peter Quinn]

Spiral up may tear top edge, spiral down may tear bottom edge, spirals in general tend to be more grabby IME and are not the panacea many seem to think. Are you doing the cutting with a router/trammel? I'd make circle templates out of mdf using....whatever bit you like, because mdf mills like cheese wiz. Then I'd cut as close as your eyes let you to be line, attach the templates and flush trim to the templates, this can be done with a spiral compression flush trim, or just a 2z shear bit, you can climb cut as necessary on the end grain.....you want to stay always on the down hill. The table saw can also be very effective for cutting circles, there are a a few good video tutorials on you tube on that.

[Mel Fulks]

Fastest thing is ONE FLUTE carbide bit 1/2 inch diameter . Some of them can vibrate a little but usually not until after a sharpening or two. MUCH faster than two flute. Haven't seen any with guide bearings on them.

[Kevin Gagne]

Just bought this jig http://www.circleperfecttools.com/#!...e-circle-guide and have been using it with a spiral up-cut bit and has been working great.

[Randy Rose]

Thank you gentlemen.