saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom hole.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

-MIKE- wrote in :

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom hole.

I'm curious why you would need a totally flat bottomed hole.

On 3/29/2016 6:12 AM, Doug Miller wrote:
-MIKE- wrote in :

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom hole.

I'm curious why you would need a totally flat bottomed hole.



If you are using a bolt/nut/screw and flat washer in that hole the
washer makes better contact with the bottom of the hole.

On 3/29/2016 9:40 AM, Leon wrote:
On 3/29/2016 6:12 AM, Doug Miller wrote:
-MIKE- wrote in :

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit.
Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom hole.

I'm curious why you would need a totally flat bottomed hole.



If you are using a bolt/nut/screw and flat washer in that hole the
washer makes better contact with the bottom of the hole.

But the emphasis (as I read it) was why a TOTALLY flat bottomed hole? I
understand what you're saying, Leon, but if I'm using ANY Forstner bit
to drill say, a 1" hole in a board so I can insert a small fender washer
and a bolt or screw what difference will that slight pip in the dead
center make? If it's a screw the pilot hole will be there, if it's a
bolt, there will be a hole rather than the pip.

On Tuesday, March 29, 2016 at 10:40:57 AM UTC-4, Leon wrote:
On 3/29/2016 6:12 AM, Doug Miller wrote:
-MIKE- wrote in :

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom hole.

I'm curious why you would need a totally flat bottomed hole.



If you are using a bolt/nut/screw and flat washer in that hole the
washer makes better contact with the bottom of the hole.

....or a thrust bearing. BTDT

http://www.vxb.com/v/vspfiles/photos/F3-8-2.jpg

There's one at the bottom of the steering shaft for this
Soap Box Derby car:

http://tinyurl.com/DerbySteer

Full Link

http://i440.photobucket.com/albums/q...psi9pjxbgv.jpg

However, I think we have a slight disconnect here. Doug used the word
"totally" in his post. Your flat washer (and my bearing) will both work
in the hole created by a Fortsner bit with a center point, which does not
create a totally flat hole. (I believe that that is what EC is actually
asking about)

The only reason I can think of for a totally flat bottomed hole would be
for decorative purposes.

On 3/29/16 6:12 AM, Doug Miller wrote:
-MIKE- wrote in
:

On 3/28/16 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet
wrote:
saw flat bottom forstner bits advertised and first thing i
thought of was all forstner bits are flat bottom but i wonder
if that is true

It's not true. I would guess that most Forstner bits are *not*
flat bottomed, as shown here. The center brad is used to get the
bit started without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2
Forstner bits to get a flat bottom hole. Grind the center brad
off of one bit. Start the hole with the center brad of the "full"
bit and when the hole gets deep enough to hold the other one
centered, switch bits and finish the hole.


That's exactly what I've done when I need a totally flat bottom
hole.

I'm curious why you would need a totally flat bottomed hole.


I'm letting some coffee work on my brain to fire up the correct synapses
in order to recollect the past projects I've needed them.

However, on a recent cabinet rehab, the client wanted cup hinges on her
existing doors which were abnormally thin. Not only did I have to scour
the globe/google to find euro-hinges with the shallowest cups, but I had
to grind off the pilot point on my 35mm forstner to keep it from
piercing the outer edge of the cabinet.

Yes, it was a butt-pucker job as there was less than 1/16" outer veneer
left after the cup holes were drilled. Client wants, client gets. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 3/28/2016 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


Actually a true Forster bit has no saw teeth and does not require a
center brad point to guide it. I have drilled numerous quarter circle
holes with only 1/4 of the bit cutting into the wood. The perimeter of
the bit does the guiding. This is all done however with a DP, not a
hand held drill.

On Tuesday, March 29, 2016 at 12:09:23 AM UTC-4, Leon wrote:
On 3/28/2016 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


Actually a true Forster bit has no saw teeth and does not require a
center brad point to guide it. I have drilled numerous quarter circle
holes with only 1/4 of the bit cutting into the wood. The perimeter of
the bit does the guiding. This is all done however with a DP, not a
hand held drill.

Like this one...no center point.

http://www.jamestowndistributors.com...=Forstner+Bits

On Tue, 29 Mar 2016 07:13:30 -0700, DerbyDad03 wrote:

On Tuesday, March 29, 2016 at 12:09:23 AM UTC-4, Leon wrote:

Actually a true Forster bit has no saw teeth and does not require a
center brad point to guide it. I have drilled numerous quarter circle
holes with only 1/4 of the bit cutting into the wood. The perimeter of
the bit does the guiding. This is all done however with a DP, not a
hand held drill.

You're right, Leon. But I would add one caution. If you're drilling a
full round hole, the force of the bit is equal in all directions. If
you're drilling half a hole, the force is all in one direction. If you
don't have the work secured, the bit can pull the work (and your hand)
into it - DAMHIKT!


Like this one...no center point.

http://www.jamestowndistributors.com...ow_product.do?
pid=12353&familyName=Forstner+Bits

They're really fond of those bits aren't they? Four times or more the
price of a Freud or Bosch with a center point!


--
Nobody expects the Spanish Inquisition!

On 2016-03-29, Trenbidia wrote:

They're really fond of those bits aren't they? Four times or more the
price of a Freud or Bosch with a center point!

.....and to what advantage!?

So, a center point leaves a little dimple at the bottom of the cut.
How is this detrimental to the flat bottom? I could see the added
expense of pointless bits if the bit point left a protruding dimple on
the bottom, but it does not. A flat washer will lay jes as flat with
a negative dimple under it as without. Or am I missing something?

nb

On 3/29/2016 11:22 AM, Trenbidia wrote:
On Tue, 29 Mar 2016 07:13:30 -0700, DerbyDad03 wrote:

On Tuesday, March 29, 2016 at 12:09:23 AM UTC-4, Leon wrote:

Actually a true Forster bit has no saw teeth and does not require a
center brad point to guide it. I have drilled numerous quarter circle
holes with only 1/4 of the bit cutting into the wood. The perimeter of
the bit does the guiding. This is all done however with a DP, not a
hand held drill.

You're right, Leon. But I would add one caution. If you're drilling a
full round hole, the force of the bit is equal in all directions. If
you're drilling half a hole, the force is all in one direction. If you
don't have the work secured, the bit can pull the work (and your hand)
into it - DAMHIKT!

Yes! and why I mentioned doing this on a DP. ;~)







Like this one...no center point.

http://www.jamestowndistributors.com...ow_product.do?
pid=12353&familyName=Forstner+Bits

They're really fond of those bits aren't they? Four times or more the
price of a Freud or Bosch with a center point!



Good Forstner bits are not cheap. Cheap Forstner bits can be cheap.

With out a center spur the bit has to be well made and sharpened to keep
it on track. FWIW I would choose a Fuller bit over a Bosch or Freud if
I needed to accomplish an excellent result repeatedly hundreds of times.

On 3/29/2016 9:13 AM, DerbyDad03 wrote:
On Tuesday, March 29, 2016 at 12:09:23 AM UTC-4, Leon wrote:
On 3/28/2016 8:16 PM, DerbyDad03 wrote:
On Monday, March 28, 2016 at 7:24:38 PM UTC-4, Electric Comet wrote:
saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder if that is true

It's not true. I would guess that most Forstner bits are *not* flat
bottomed, as shown here. The center brad is used to get the bit started
without wandering.

https://www.pennstateind.com/graphic...x/PKFB2732.jpg

I have heard of (but never seen) the technique of using 2 Forstner bits
to get a flat bottom hole. Grind the center brad off of one bit. Start the
hole with the center brad of the "full" bit and when the hole gets deep
enough to hold the other one centered, switch bits and finish the hole.


Actually a true Forster bit has no saw teeth and does not require a
center brad point to guide it. I have drilled numerous quarter circle
holes with only 1/4 of the bit cutting into the wood. The perimeter of
the bit does the guiding. This is all done however with a DP, not a
hand held drill.

Like this one...no center point.

http://www.jamestowndistributors.com...=Forstner+Bits


BUT not even that bit creates a "totally" flat bottom hole, it still
creates an indentation around the perimeter of the bottom of the hole,
and typically about as deep as the spur center on those that have them.

The Forstner bit requires the perimeter of the hole to be cut first,
like a brad point bit and then the flutes cutting edges cut out the
center and leave a flat surface.

Electric Comet wrote:

saw flat bottom forstner bits advertised and first thing i thought of
was all forstner bits are flat bottom but i wonder

Yes true Forster bits drill flat bottom holes. They also leave a small
dimple and often an indention around the perimeter of the bottom of the
hole, but the bottom is flat.