Best Bit?
-
- Vectric Apprentice
- Posts: 78
- Joined: Tue Jun 24, 2014 3:58 pm
- Model of CNC Machine: Laguna IQ
Best Bit?
While doing 3D, I typically use a 1/4 ball nose for roughing and finishing. I have my feed rate at 60 and plunge rate at 40. My step over is 10%. Is there a better bit or way to make my final cut show more detail?
- Rcnewcomb
- Vectric Archimage
- Posts: 5887
- Joined: Fri Nov 04, 2005 5:54 am
- Model of CNC Machine: 24x36 GCnC/WinCNC with ATC
- Location: San Jose, California, USA
- Contact:
Re: Best Bit?
For finishing preview it with a 1/8" or a 1/16" ballnose. If it is noticeably better then you may need to use a smaller bit for the finish toolpath.Is there a better bit or way to make my final cut show more detail?
The nice thing about the preview is you can try it with various bits and then decide which bit is best for your project.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop
10 fingers in, 10 fingers out, another good day in the shop
-
- Vectric Craftsman
- Posts: 107
- Joined: Thu Nov 28, 2019 6:12 am
- Model of CNC Machine: Onefinity X-50 Woodworker
- Location: Fresno, CA
Re: Best Bit?
I typically use a 1/4" ball nose for roughing with the feed set to around 120-150 and haf that for plunge rate and a stepover of 40-60%. For the finish path I will typically use a 1/8" tapered ball nose adjusting the feed rate to get a good chip load (again around 120 - 150 ipm) and, more critically, reduce the stepover to 8-10%.. If I need better detail I will go to a 1/16" tapered ballnose
-
- Vectric Apprentice
- Posts: 78
- Joined: Tue Jun 24, 2014 3:58 pm
- Model of CNC Machine: Laguna IQ
Re: Best Bit?
Thanks for the tips.
- ohiolyons
- Vectric Wizard
- Posts: 1702
- Joined: Wed May 27, 2009 7:16 pm
- Model of CNC Machine: Laguna IQ
- Location: Kettering, Ohio
Re: Best Bit?
It also depends on the size of your carving.
1/4" EM and BN will not yield a good looking results on a 3"x3" carving, but could deliver excellent results on a 24"x24" carving.
Design and Make use to have guidance on bit sizing for their files, but has sense been taken it down.
Their models were optimized around 1/8" BN for finishing.
If you enlarged the model you might (depending on the level of detail) get away with a larger finishing bit.
If you reduced the model you might (depending on the level of detail) you might need a smaller finishing bit.
It mostly depends on how intricate your model is and how big of cusps are you willing to put up with.
Don't forget you love of sanding too.
1/4" EM and BN will not yield a good looking results on a 3"x3" carving, but could deliver excellent results on a 24"x24" carving.
Design and Make use to have guidance on bit sizing for their files, but has sense been taken it down.
Their models were optimized around 1/8" BN for finishing.
If you enlarged the model you might (depending on the level of detail) get away with a larger finishing bit.
If you reduced the model you might (depending on the level of detail) you might need a smaller finishing bit.
It mostly depends on how intricate your model is and how big of cusps are you willing to put up with.
Don't forget you love of sanding too.
John Lyons
CNC in Kettering, Ohio
CNC in Kettering, Ohio
- adze_cnc
- Vectric Wizard
- Posts: 4331
- Joined: Sat Jul 27, 2013 10:08 pm
- Model of CNC Machine: AXYZ 4008
- Location: Vancouver, BC, Canada
Re: Best Bit?
"Best bit” and “how long is a piece of string” are pretty comparable.
A 1/4” ball nose cutter on a very samil project (say 3” x 3”) might be acceptable if that proejct is just a simple dome or dish shape. It would be less than useful if that project was an elaborate Chinese dragon and flower model. Then a tapered ball nose with a small (0.25mm R ?) tip might be more appropriate.
Whenever I hear the term “best practices” used I like to say “there are no best practices only alternatives”. We could extend that to choosing the cutters we use for projects.
My one suggestion though is to consider, as ohiolyons alluded to, using an end mill as a roughing tool rather than a ball nose bit.
A 1/4” ball nose cutter on a very samil project (say 3” x 3”) might be acceptable if that proejct is just a simple dome or dish shape. It would be less than useful if that project was an elaborate Chinese dragon and flower model. Then a tapered ball nose with a small (0.25mm R ?) tip might be more appropriate.
Whenever I hear the term “best practices” used I like to say “there are no best practices only alternatives”. We could extend that to choosing the cutters we use for projects.
My one suggestion though is to consider, as ohiolyons alluded to, using an end mill as a roughing tool rather than a ball nose bit.