Galoots,

I stopped to take a few pictures of my Work In Progress.
It isn't my design, and isn't what I would build for myself,
but it is what my friend wanted.

I tried to load the photos on the groups.io site, but when
one tries to acquire a link to the individual pictures you
get really strange looking URLs. So I just included the
link to my album. You'll have to dig up the pictures and
try and match them to my words.

Here you go...
https://groups.io/g/oldtools/album?id=267353

I decided to use a 10 degree wedge for the tusk tenons.
that seems to be small enough to stick and large enough
to unstick without having to hammer the heck out of it.

I've made this kind of thing before, so I rummaged around
for the 10 degree paring block I recall having made.
There it was, along with the sample wedges. 10, 11, and
12 degree wedge blanks, but only the 10 degree paring
block. 'Cause that's what I ended up using last time.

I dunno why, intuition or inspiration, but something moved
me to stick the wedge against the block and slide a square
up against them. Not square. Out came the protractor.
The wedge is a neat 10 degrees, but the paring block
was 12. Despite having "10" literally written all over it.

Should I switch to 12 or start a fight with the tools to
fix this thing? I could hear you all out there chanting 'fight!
fight! fight!', so I pulled out some really precise tools and
set about adjusting the paring block to match the
numbers on it. That end grain red oak is tough but
it behaves quite nicely, so I soon had an actual 10
degree paring block. yay.

So.
What was I doing?
Right, wedge mortises.

I set a double square to make the layout easy
and proceeded to make a sample out of an offcut.
I used a very nice #8 auger bit to clear the bulk
of the waste from the mortise, then pared it square.
The paring block was clamped on to guide the final
cut.

The sample was really good, so I proceeded to
botch the cutting of the first real mortise. Luckily,
the wedges I made up (neanderbuddy work, not
shown here) are big enough to do the job even on
the mis-cut mortise.

Once I figured out which way was UP, the layout
and cutting of the rest of the mortises was quick
and easy. The shelf unit is mostly done now, apart
for some finish. That will probably be orange shellac.

Darrell
uh oh, now I have to start on that lying press.

-- 
Oakville ON
Wood Hoarder, Blade Sharpener, and Occasional Tool User

Darrell asks about wedge angles:

====
I decided to use a 10 degree wedge for the tusk tenons.
that seems to be small enough to stick and large enough
to unstick without having to hammer the heck out of it.
====

Degrees work pretty well in math class, but for woodworking I have found that
"rise and run" ratios are easier to use. For Krenov-style plane wedges I was
taught to use a ratio of 1:10, which works well for me. YMMV.

Here are some ratios that cover a reasonable range for wedges and their
equivalents in degrees:

1:4 is about 14 degrees
1:5 is about 11.3 degrees
1:6 is about 9.5 degrees
1.7 is about 8.1 degrees
1:8 is about 7.1 degrees
1:9 is about 6.3 degrees
1:10 is about 5.7 degrees
1:11 is about 5.2 degrees
1:12 is about 4.4 degrees

I find that ratios are easier to mark out and reproduce consistently. YMMV.

Cheers,
Chuck Taylor
north of Seattle USA

On Sat., Nov. 26, 2022, 8:36 p.m. Chuck Taylor,  wrote:

> Darrell asks about wedge angles:
>
>
> Here are some ratios that cover a reasonable range for wedges and their
> equivalents in degrees:
>
> 1:4 is about 14 degrees
> 1:5 is about 11.3 degrees
> 1:6 is about 9.5 degrees
> 1.7 is about 8.1 degrees
> 1:8 is about 7.1 degrees
> 1:9 is about 6.3 degrees
> 1:10 is about 5.7 degrees
> 1:11 is about 5.2 degrees
> 1:12 is about 4.4 degrees
>
> I find that ratios are easier to mark out and reproduce consistently. YMMV.
>
> Cheers,
> Chuck Taylor
> north of Seattle USA
>

Thanks Chuck
I'm going to print this out and stick it on the shop wall


-- wood hoarder, blade sharpener, and occasional tool user

If you need this information and have access to a calculator with trig
functions, you can use the arc tangent to get this angle. This varies
according to the calculator, but you enter the number, then press the
1/X function key, then (usually) you press the INV key followed by the
TAN key. 

So, on my calculator, the ratio of 1:9 gives me
6.3401917459099093959941376648275 degrees. Not that the fraction
matters. 

YMMV. Void where prohibited by natural law or the imprecision inherent
in a pencil line.

Gary Katsanis
Albion New York, USA
with thanks to Chuck Taylor for suggesting this eminently practical
approach

	-----------------------------------------From: "Darrell" 
To: "Chuck Taylor"
Cc: "oldtools@g..."
Sent: Sunday November 27 2022 5:56:15PM
Subject: Re: [oldtools] knockdown shelf project continues to entertain
me

 On Sat., Nov. 26, 2022, 8:36 p.m. Chuck Taylor,  wrote:

 > Darrell asks about wedge angles:
 >
 >
 > Here are some ratios that cover a reasonable range for wedges and
their
 > equivalents in degrees:
 >
 > 1:4 is about 14 degrees
 > 1:5 is about 11.3 degrees
 > 1:6 is about 9.5 degrees
 > 1.7 is about 8.1 degrees
 > 1:8 is about 7.1 degrees
 > 1:9 is about 6.3 degrees
 > 1:10 is about 5.7 degrees
 > 1:11 is about 5.2 degrees
 > 1:12 is about 4.4 degrees
 >
 > I find that ratios are easier to mark out and reproduce
consistently. YMMV.
 >
 > Cheers,
 > Chuck Taylor
 > north of Seattle USA
 >

 Thanks Chuck
 I'm going to print this out and stick it on the shop wall

 -- wood hoarder, blade sharpener, and occasional tool user

 >

 



Links:
------
[1] https://groups.io/g/oldtools/unsub

Oh dear...
I know Gary knows this, but others may not. The trigonometry functions in
some calculators use radians rather than degrees (so instead of dividing a
circle into 360 degrees, circles are divided into 2pi radians, or about
6.283 radians.) So if you tried this on your calculator and got 0.1106 yada
yada, and might be wondering what you or Gary did wrong, then you have your
answer.
Some calculators let you specify units up front. You can also ask google to
do the work for you: if you enter "arctan(1/9) in degrees" without the
quotes, you'll get the answer in degrees as Gary suggests. If you're not
near google or really love your calculator, you can convert radians to
degrees by multiplying by (360/6.2832) or 57.295 to get the right answer..
And if that don't do it for ya, Lost Art Press sells something that I think
is called a Bevel Monkey that will help you set your bevel gauge to
specific angles. It is helpfully labeled in degrees.

When I first reads Chuck’s note with the table I was sure that geometry was the
basis.  But I spent two days trying to figure out what, but the arc tangent
never came out right.  I double checked that I had the correct numerator and
denominator, but it wasn’t even close!!

I finally realized that my calculator was set to do angles in radians - Duh!!

—Scott
Who accepts that occaionally doing something stupid is good for the soul (and
the ego).

On Dec 1, 2022, at 2:55 PM, gtgrouch via groups.io<http://groups.io>
mailto:gtgrouch=rochester.rr.com@g...>> wrote:

If you need this information and have access to a calculator with trig
functions, you can use the arc tangent to get this angle. This varies
according to the calculator, but you enter the number, then press the
1/X function key, then (usually) you press the INV key followed by the
TAN key.

So, on my calculator, the ratio of 1:9 gives me
6.3401917459099093959941376648275 degrees. Not that the fraction
matters.

YMMV. Void where prohibited by natural law or the imprecision inherent
in a pencil line.

Gary Katsanis
Albion New York, USA
with thanks to Chuck Taylor for suggesting this eminently practical
approach

       -----------------------------------------From: "Darrell"
To: "Chuck Taylor"
Cc: "oldtools@g...<mailto:oldtools@g...>"
Sent: Sunday November 27 2022 5:56:15PM
Subject: Re: [oldtools] knockdown shelf project continues to entertain
me

On Sat., Nov. 26, 2022, 8:36 p.m. Chuck Taylor,  wrote:

Darrell asks about wedge angles:


Here are some ratios that cover a reasonable range for wedges and
their
equivalents in degrees:

1:4 is about 14 degrees
1:5 is about 11.3 degrees
1:6 is about 9.5 degrees
1.7 is about 8.1 degrees
1:8 is about 7.1 degrees
1:9 is about 6.3 degrees
1:10 is about 5.7 degrees
1:11 is about 5.2 degrees
1:12 is about 4.4 degrees

I find that ratios are easier to mark out and reproduce
consistently. YMMV.

Cheers,
Chuck Taylor
north of Seattle USA




---------------------------------------------------
Scott Stager
Columbia MO
573-474-5955 home
573-424-4764 cell
stagers@m...<mailto:stagers@m...>

Oh dear indeed. In suggesting the use of slopes instead of degrees, I
deliberately left out the gory details because it isn't necessary to deal with
gory details in order to make furniture. Yes, I did use trigonometry to
calculate the degree equivalents in order to illustrate that the results are
essentially the same, but it's much simpler not to deal with degrees at all. You
don't suppose that 18th-century galoots used degrees in marking out their
furniture, do you? It is much easier to set your adjustable bevel gauge using
slopes rather than degrees, and much more repeatable.

Another practical use of slopes is in evaluating bevel angles of chisels and
plane irons. If the width of the bevel is twice the thickness of the blade/iron,
then you have a 30-degree bevel. If it's more than 2:1, then you have a
shallower angle. If it's less, then you have a steeper angle.

For the curious, I used an HP48 calculator emulator on my smartphone (set to
calculate in degrees) to make that table, and I did indeed use the arctangent
function.

Cheers,
Chuck Taylor
north of Seattle USA

Well, for people who know all the angles, it's just a matter of
degree. 

*ducking and running away!*

	-----------------------------------------From: "Chuck Taylor" 
To: "gtgrouch@r...", "Curt Seeliger"
Cc: "Darrell", "oldtools@g..."
Sent: Thursday December 1 2022 5:21:44PM
Subject: Re: [oldtools] knockdown shelf project continues to entertain
me

 Oh dear indeed. In suggesting the use of slopes instead of degrees, I
deliberately left out the gory details because it isn't necessary to
deal with gory details in order to make furniture. Yes, I did use
trigonometry to calculate the degree equivalents in order to
illustrate that the results are essentially the same, but it's much
simpler not to deal with degrees at all. You don't suppose that
18th-century galoots used degrees in marking out their furniture, do
you? It is much easier to set your adjustable bevel gauge using slopes
rather than degrees, and much more repeatable. 

 Another practical use of slopes is in evaluating bevel angles of
chisels and plane irons. If the width of the bevel is twice the
thickness of the blade/iron, then you have a 30-degree bevel. If it's
more than 2:1, then you have a shallower angle. If it's less, then you
have a steeper angle.

 For the curious, I used an HP48 calculator emulator on my smartphone
(set to calculate in degrees) to make that table, and I did indeed use
the arctangent function.

 Cheers,
 Chuck Taylor
 north of Seattle USA

Chuck,

The 48GX was just released when I started school, one of the best $350 
purchases I have ever made. The emulator on my iPhone is my favorite 
app, works well and my phone actually fits in my pocket making it handy 
when I have to venture out on the shop floor at work.

There are several versions. My favorite is the i48 app by Daniel Parnell.
Of the versions I've tried it looks the best, works well, and is free. I 
believe it is also available for android.

Troy
RPN rules!

TrigoNOmitry, Humph. THAT was off-charter even back in high school when I
had to study it. Real Galoots cut by eye, and then do it over until it
fits. Trust me on this.

Phil E.