jj

15/01/2007 2:52 PM

TS Cutting not quite flat bottoms

Folks,

I'm cutting a double tenon on the TS, with about 0.17 between tenons.
Using a shop-made tenon jig to cut the space between the tenons I wind
up with an inverted V shape on the bottom, sticking up maybe 0.010"
(that's a guestimate).

Tried two blades: a Freud 80 toother, and a Freud 50 tooth combination
blade.

Any ideas why this wouldn't be flat? The 80 tooth blade is only a year
old and hasn't seen too much wood.

Thanks,
Jack


This topic has 7 replies

Mi

"Mike in Arkansas"

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 3:10 PM


[email protected] wrote:
> Folks,
>
> I'm cutting a double tenon on the TS, with about 0.17 between tenons.
> Using a shop-made tenon jig to cut the space between the tenons I wind
> up with an inverted V shape on the bottom, sticking up maybe 0.010"
> (that's a guestimate).
I believe that would be because your blades are Alternate top bevel
blades. To get a flat bottom you will need a blade with a flaat topl
tooth grind.

Mb

"MB"

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 4:58 PM

What about using a rip blade? Don't those have flat teeth?

LB

Larry Blanchard

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 8:22 PM

MB wrote:

> What about using a rip blade? Don't those have flat teeth?
>

And there are ATBR blades out there (ATBRaker).

--
It's turtles, all the way down

MD

"Morris Dovey"

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 5:08 PM

[email protected] wrote:
| Folks,
|
| I'm cutting a double tenon on the TS, with about 0.17 between
| tenons. Using a shop-made tenon jig to cut the space between the
| tenons I wind up with an inverted V shape on the bottom, sticking
| up maybe 0.010" (that's a guestimate).
|
| Tried two blades: a Freud 80 toother, and a Freud 50 tooth
| combination blade.
|
| Any ideas why this wouldn't be flat? The 80 tooth blade is only a
| year old and hasn't seen too much wood.

I'm not familiar with those two blades; but most are ATB (alternate
tooth bevel). Take a really close look at the blades and you'll see
that the teeth aren't flat on top.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

JC

"J. Clarke"

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 11:30 PM

On Mon, 15 Jan 2007 14:52:59 -0800, [email protected] wrote:

> Folks,
>
> I'm cutting a double tenon on the TS, with about 0.17 between tenons.
> Using a shop-made tenon jig to cut the space between the tenons I wind
> up with an inverted V shape on the bottom, sticking up maybe 0.010"
> (that's a guestimate).
>
> Tried two blades: a Freud 80 toother, and a Freud 50 tooth combination
> blade.
>
> Any ideas why this wouldn't be flat? The 80 tooth blade is only a year
> old and hasn't seen too much wood.

Examine the blade closely and you should find that there are no flat teeth,
they are set to either the left or to the right--this is called an
"Alternate Top Bevel" grind and it is the most commonly encountered.

Not a function of the age or sharpness of the blade, but of the design.

If you need a flat bottom you need a special grind on the
blade. Forrest has custom grinds on the Woodworker II blade for various
purposes--<http://www.forrestblades.com/woodworker_2.htm>. The
WW10401125 is probably what you need but you may want to call them and
explain what you are trying to do and ask for a recommendation.

--

--John

to email, dial "usenet" and validate

(was jclarke at eye bee em dot net)

Wf

"WoodButcher"

in reply to "[email protected]" on 15/01/2007 2:52 PM

15/01/2007 4:30 PM

Others have identified the cause of your problem and a couple
have provided some not so inexpensive solutions.
If it were me I'd just use a file on edge to scrape the ridge from
between the tenons, or use a chisel to lower the bridge between
the mortises till it clears the tenon ridge.

Art

<[email protected]> wrote in message
news:[email protected]...
> Folks,
>
> I'm cutting a double tenon on the TS, with about 0.17 between tenons.
> Using a shop-made tenon jig to cut the space between the tenons I wind
> up with an inverted V shape on the bottom, sticking up maybe 0.010"
> (that's a guestimate).
>
> Tried two blades: a Freud 80 toother, and a Freud 50 tooth combination
> blade.
>
> Any ideas why this wouldn't be flat? The 80 tooth blade is only a year
> old and hasn't seen too much wood.
>
> Thanks,
> Jack
>

LH

Lew Hodgett

in reply to "[email protected]" on 15/01/2007 2:52 PM

16/01/2007 12:13 AM

[email protected] wrote:
<snip>

> Tried two blades: a Freud 80 toother, and a Freud 50 tooth combination
> blade.
>
> Any ideas why this wouldn't be flat? The 80 tooth blade is only a year
> old and hasn't seen too much wood.

You can't get there from here with either of those blades (I have both
of them), time to add the Freud dado set to your arsenal if you want a
flat bottom.

Lew


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