Sharing an experience.
I was cutting some circular table tops and using a router with a jig
to make the circles accurate after cutting the blanks with a band saw.
I had done this before using a solid carbide 1/4" onsrud style bit and
broke the darn bit. I thought a straight cut bit would not be as
fragile, and broke one of them as well. Instead of running out and
buying a new bit I used a 3/8' bit which took another 1/16" off the
radius - which I can live with. This time however I went halfway
through the top, and made 2 slow passes. I still have that bit in the
router and learned a lesson. Trying to save time lost me 2 bits and
not the 25 cent variety either.

I would move to 1/2" bits if at all possible. Those 1/4"
bits are very fragil and not really up to the job you
are giving them.

Norbert wrote:

Sharing an experience.
I was cutting some circular table tops and using a router with a jig
to make the circles accurate after cutting the blanks with a band saw.
I had done this before using a solid carbide 1/4" onsrud style bit and
broke the darn bit. I thought a straight cut bit would not be as
fragile, and broke one of them as well. Instead of running out and
buying a new bit I used a 3/8' bit which took another 1/16" off the
radius - which I can live with. This time however I went halfway
through the top, and made 2 slow passes. I still have that bit in the
router and learned a lesson. Trying to save time lost me 2 bits and
not the 25 cent variety either.

Pat Barber wrote:
I would move to 1/2" bits if at all possible. Those 1/4"
bits are very fragil and not really up to the job you
are giving them.

How much material were you trying to take off? Were you just a hair
from the pencil line on the bandsaw, so you were just smoothing the
edge, or were you taking off a more significant 3/16 or something like
that?
For a tiny bit, I would have thought the carbide spiral bit would be a
good choice, but for any thickness or depth, I like a 3/4" or 1" dia
straight bit.
Andy

Pat Barber wrote:

I would move to 1/2" bits if at all possible. Those 1/4"
bits are very fragil and not really up to the job you
are giving them.

Absolutely.

I have a 1/2" shank, 3/4" dia, 3" lg, 2 flute bit barbide bit complete
with a bottom bearing that gets used for this kind of work.

The cabinet shop that makes the round MDF tables for department store
window displays uses same package but without bearing.

Lew




Lew

Being that carbide is a brittle material I've never thought solid
carbide bits especially 1/4" shank were a good idea. Was the second bit
solid carbide also
Joe

Norbert wrote:
Sharing an experience.
I was cutting some circular table tops and using a router with a jig
to make the circles accurate after cutting the blanks with a band saw.
I had done this before using a solid carbide 1/4" onsrud style bit and
broke the darn bit. I thought a straight cut bit would not be as
fragile, and broke one of them as well. Instead of running out and
buying a new bit I used a 3/8' bit which took another 1/16" off the
radius - which I can live with. This time however I went halfway
through the top, and made 2 slow passes. I still have that bit in the
router and learned a lesson. Trying to save time lost me 2 bits and
not the 25 cent variety either.

The solid carbide bit was broken trying to do the complete job without
the bandsaw to do the major roughing. The second bit was a 1/4 inch
straight carbide not solid. I thought the steel shank might be
stronger. I was removing 1/8 inch or so of 3/4 thick ash. Next time
I will use a 1/2 inch shank bit and adjust my jig to compensate for
the size of the bit. I realize now I was pushing the 1/4 inchers too
far, and probably going too fast
The 1/2 inch shank is good advice, and since I'm removing material
from the outside only the bit diameter isn't a problem.
Thanks for the feedback everyone.

On 27 Jun 2006 13:07:03 -0700, wrote:

Being that carbide is a brittle material I've never thought solid
carbide bits especially 1/4" shank were a good idea. Was the second bit
solid carbide also
Joe

Norbert wrote:
Sharing an experience.
I was cutting some circular table tops and using a router with a jig
to make the circles accurate after cutting the blanks with a band saw.
I had done this before using a solid carbide 1/4" onsrud style bit and
broke the darn bit. I thought a straight cut bit would not be as
fragile, and broke one of them as well. Instead of running out and
buying a new bit I used a 3/8' bit which took another 1/16" off the
radius - which I can live with. This time however I went halfway
through the top, and made 2 slow passes. I still have that bit in the
router and learned a lesson. Trying to save time lost me 2 bits and
not the 25 cent variety either.

I have a circle jig that is calibrated for 1/4" bits. I have cut through 3/4
oak on a number of occasions with no problem using both spiral and two flute
bits. Feedrate is key and keeping the slot clean.
"Norbert" wrote in message
...
The solid carbide bit was broken trying to do the complete job without
the bandsaw to do the major roughing. The second bit was a 1/4 inch
straight carbide not solid. I thought the steel shank might be
stronger. I was removing 1/8 inch or so of 3/4 thick ash. Next time
I will use a 1/2 inch shank bit and adjust my jig to compensate for
the size of the bit. I realize now I was pushing the 1/4 inchers too
far, and probably going too fast
The 1/2 inch shank is good advice, and since I'm removing material
from the outside only the bit diameter isn't a problem.
Thanks for the feedback everyone.

On 27 Jun 2006 13:07:03 -0700, wrote:

Being that carbide is a brittle material I've never thought solid
carbide bits especially 1/4" shank were a good idea. Was the second bit
solid carbide also
Joe

Norbert wrote:
Sharing an experience.
I was cutting some circular table tops and using a router with a jig
to make the circles accurate after cutting the blanks with a band saw.
I had done this before using a solid carbide 1/4" onsrud style bit and
broke the darn bit. I thought a straight cut bit would not be as
fragile, and broke one of them as well. Instead of running out and
buying a new bit I used a 3/8' bit which took another 1/16" off the
radius - which I can live with. This time however I went halfway
through the top, and made 2 slow passes. I still have that bit in the
router and learned a lesson. Trying to save time lost me 2 bits and
not the 25 cent variety either.