Fuzzy cuts

[sevendale]

Hi. I just cut some practice curves in alder 4/4 wood. I got some very fuzzy patches. I know alder is one of the fuzzier woods but I got similar results in yellow pine.
1/4" spiral upcut running 1.25"/s at 13,000rpm
taking just a 1/4" per pass.
Too slow? Too bad?

Thanks!

[Gary Campbell]

Rob...
Alder is one of the tough ones to make look good. Your speed & feed are very close to what I would try. If you have a test piece try changing both speed and RPMs up and down on a straight cut snd look for small improvements. IF no changes are apparent, change the bit geometry. My go to bit is usually a single O flute from Belin or Onsrud. The single flute allows a slower move speed while maintaining chipload.
Hope this helps, Gary

[gene]

Rob
Try a straight cutter and boost the travel speed to 2.75 to 3 ips and leave the spindle at 13000. you will see a better cut . also make sure that the bit is sharp

[knight_toolworks]

a downcut bit will help a lot. rpms does not seem to matter much on clean cut in solid woods from what I have tried. the bit made more of a difference.
so far on maple and poplar and tropicals I find a downcut bit cuts cleaner and more accurately then any other bit. though straight bits are second to them.

[sevendale]

Gary, I'll try a single O on some southern yellow pine which is readily available here: alder is a 50 mile drive.
Gene, the straight cutter yes, but I'm scared to run this old machine fast........ok I'll take a dare... the bits are all new I just got started.
Steve, I'll try the downcut too.
And I'll make the drive to get some maple which is the wood I need for this project anyway.
Thanks guys

[rcnewcomb]

I've found that the cut speeds for hard maple are much slower than for pine. When I prototyped in pine and then tried to use the same toolpath file and speed on hard maple -- well, let's just say I learned a lot that day.

With pine I was moving at about 5IPS to keep the pitch from building up on the bit.

I cut hard maple at about 1.5-2 IPS at 13KRPM.

Maple will not get the fuzzies like pine or alder, but is more sensitive to climb vs. conventional cutting. One direction will have a perfect edge and the other will look really rough.

What type of cuts are you doing: through-cuts or pocketing? Steve is right, the downspiral bits really help minimize tear-out.

Will you also be doing v-carving, 3D carving?

[jseiler]

I was making a frame for light panels that was going to be painted, so I picked alder because it was relatively cheap. I ended up blowing out corners, splitting edges along grain, etc. All sorts of problems. I ended up buying more to finish the project. For all the money I spent on scrapping wood, I could have bought maple which usually machines quite nicely without such hassles.

[sevendale]

Randall, yes, I intend to carve some lettering for my own signs, 3D is the goal, ArtCam a distant vision beyond my wallet by a long country mile....... right now I'm cutting jigs for gluing up projects (stools, birdhouses, simple practice work)so I'm cutting rabbets dadoes and through cuts with some curves holes and area clears in 8/4 pine dressed to 1 1/4", alder 4/4 I had left over, and plywood because it's cheap and stable and stacked all over the place. Today: comparison cuts as suggested above.
Thanx

[rcnewcomb]

Hard maple is wonderful for carving once you get your speeds dialed in. Here is a project I did recently - just as it came off the 'Bot. Note that even though the bow and string are very thin, and the depth of the carving inside the bow is nearly 1/2" deep, there is surprisingly little tearout. This was a VerctorArt3D design and machined with 3D Machinist.

5098

[sevendale]

Randall, awesome. And crisp too, what bit did you use and did you have to sharpen it twice?
Do you think I could do that with this ol pre-millenium bot running on dos? Probably not; another software away.....
Keep doing that, it makes the world a better place.

[rcnewcomb]

- though I prefer the bits from Gary Beckwith...

Hard maple piece: 9"x9"
rough pass: 0.250" Onsrud downspiral at 2.0/1.0 at 16K RPM (20 minutes) (31,588 lines of code)
finish pass: 0.125 ballnose from MSC Direct at 3.0/2.0 at 16K RPM (80 minutes) 8% stepover (152,552 lines of code)

You would need to run the 3D machinst software on a Windows system. But the toolpath files would probably fit on your machine.

[sevendale]

Thank you!
I'm saving that (right here) for reference.