Woodturner's Resource
Woodturner's Resource  
  • Featured Artist    • Websites   Support Wr
Tutorials, Projects & Tips   • Event Calendar   • Tool and Book Store
  Home Page Forum HelpSearch Map TPT Resources LoginRegister
 
Page Index Toggle Pages: 1
Send Topic Print
Sharpening forstner bits (Read 199 times)
 
Jennifer Hasan
Active Member
***
Offline


WR Rocks!

Posts: 191

Beacon, ny, New York, USA
Beacon, ny
New York
USA

Sharpening forstner bits
Sep 12th, 2017 at 7:26pm
 
Does anyone have a technique to sharpen forstner bits which maintain the center point?

I've tried all sorts of ways to sharpen them but nothing maintains an edge better than the cbn wheel, but I destroy the center position not and the rim of the bit.

Thanks,

Jenn
Back to top
  
 
IP Logged
 
Register To Remove Ads
Ed Weber
WR Global Moderator
WR Patron
*****
Offline



Posts: 4,784

Wilton, California, USA
Wilton
California
USA

Gender: male

JET 1642
Grizzly G0584
Re: Sharpening forstner bits
Reply #1 - Sep 12th, 2017 at 9:16pm
 
Jennifer Hasan wrote on Sep 12th, 2017 at 7:26pm:
Does anyone have a technique to sharpen forstner bits which maintain the center point?


This is pretty much the same way I do it. There is no need to touch the center point.
This can also be done with hand files.
Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register

Back to top
  
 
IP Logged
 
Steve Arnold
Active Member
***
Offline


WR Rocks!

Posts: 135

Burbank, California, USA
Burbank
California
USA

Gender: male

Jet 1640EVS
Re: Sharpening forstner bits
Reply #2 - Sep 13th, 2017 at 10:42am
 
This is the method I use.

Forstner bit segment begins at 0:50

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
Back to top
  
 
IP Logged
 
Ed Weber
WR Global Moderator
WR Patron
*****
Offline



Posts: 4,784

Wilton, California, USA
Wilton
California
USA

Gender: male

JET 1642
Grizzly G0584
Re: Sharpening forstner bits
Reply #3 - Sep 13th, 2017 at 2:42pm
 
Steve Arnold wrote on Sep 13th, 2017 at 10:42am:
This is the method I use.

Forstner bit segment begins at 0:50

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register


This is NOT sharpening.
This is honing the back flat.
This is no different than trying to sharpen a bench chisel by only honing the back. or by sharpening a gouge byonly honing the flute. You are trying to remove too much material in the wrong area.
While it may remove a few burrs, it is not addressing the grind which creates the cutting edge.

On forstener bits, If you sharpen the bevel (the ground cutting edge) you are not changing the profile of the bit, which is some peoples concern.
If you leave the center point and perimeter alone, the bit will always cut straight no matter the condition of the cutters.
You might as well try to sharpen the area that actually does the cutting.

(this is not to be done on router bits)
I will add that on router bits, the same thing applies. You aren't actually sharpening anything, just cleaning up and/or honing the back. Any attempt to sharpen a router bit changes the diameter (because you are removing material from the perimeter).
You can hone the back once or twice but once the edge is gone you can not bring it back, period.
Back to top
  
 
IP Logged
 
Jennifer Hasan
Active Member
***
Offline


WR Rocks!

Posts: 191

Beacon, ny, New York, USA
Beacon, ny
New York
USA

Re: Sharpening forstner bits
Reply #4 - Sep 13th, 2017 at 4:55pm
 
Is this how it should be done?

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register
Back to top
  
 
IP Logged
 
Ed Weber
WR Global Moderator
WR Patron
*****
Offline



Posts: 4,784

Wilton, California, USA
Wilton
California
USA

Gender: male

JET 1642
Grizzly G0584
Re: Sharpening forstner bits
Reply #5 - Sep 13th, 2017 at 6:14pm
 
Jennifer Hasan wrote on Sep 13th, 2017 at 4:55pm:
Is this how it should be done?

Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register


IMO, no (I stand by my 2 previous posts)
That's the same video Steve linked to. While it won't hurt, it won't really help.
Back to top
  
 
IP Logged
 
Ed Weber
WR Global Moderator
WR Patron
*****
Offline



Posts: 4,784

Wilton, California, USA
Wilton
California
USA

Gender: male

JET 1642
Grizzly G0584
Re: Sharpening forstner bits
Reply #6 - Sep 14th, 2017 at 9:48am
 
Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to Login or Register

"If the chippers on your Forstner bit are also dull, they can be sharpened by filing and
stoning  the  throat  face  and  lightly  stoning  the  bevel.  To  file  the  throat  face,  you
should use an auger bit file or a small hand file. Always maintain the original angles.
This means that you must file exactly parallel to the throat and stone parallel to the
throat. Similarly when you are stoning the bevel, maintain your stone parallel to the
original bevel grind."
Back to top
  
 
IP Logged
 
Jennifer Hasan
Active Member
***
Offline


WR Rocks!

Posts: 191

Beacon, ny, New York, USA
Beacon, ny
New York
USA

Re: Sharpening forstner bits
Reply #7 - Sep 14th, 2017 at 11:57am
 
Thank you, Ed. This is great.
Back to top
  
 
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print