Please help me with carpentry angle skills

[esarratt]

I have built two sawhorses using Jack Sobon's design.  I can't get the notch correct on the vertical 2x6 (bottom right on the 1st photo).  The notch seats on the bottom of the horizontal beam.

My notch seats well on the outer surface of the 2x6, but not well on the inside (my angle is wrong).  It is worse than my picture (see below) shows.  Most of the wood in my vertical 2x6 is not touching the bottom of the horizontal beam.

I'm not worried about the structural integrity of the sawhorses.  I just know that there is a better way to do this and I know I will run into similar problems as my build progresses.

Jack's design did not specify an angle for the notch.  Literally, the directions I have posted is all that there is for the design.

The picture with the dividers is for explanatory purposes.  That is the angle I need to figure out before building my next pair.

I have most of the timber frame tools Jim Rogers has on his list for measuring and cutting.

Thank you for your help!

Here are the pics:


 

 

 

 

 

 

 

[Den-Den]

The measurement you show with dividers calculates as 0.513" (based on the "2 x 6" being 1-1/2" thick).  Sin(20 deg) x 1.5  The rounded corners of standard lumber may complicate marking and cutting.

[Remle]

To add to Den-Den's reply.
The interior angles of a right triangle add up to 180°. So in this case you have a 90° angle and a 70° angle which added together = 160°. So 180° - 160° = 20° or the slope of the cut from one side to the other of the brace stock and why Den-Den used it for his calculation for the depth of the cut.
Now for the lazy mans way, lay out a 20° angle across the width of the stock and square the low end of the line back to the notch location and saw from the high side down the the low line at both edges of the notch and chisel out the notch. Do this on the square end of the stock before cutting the taper to fit the legs.

[esarratt]

Oh yeah.  Geometry.  I forgot about that.

Thanks to you both!  Your answers were very helpful.  I am starting on my second pair.

I have become aware how beneficial a basic carpentry course is to timber framing.

 

[Tom King]

Just use the dividers to scribe the line you need to cut to on the other side.  No Math required.

I'd also suggest a sharper pencil, for a finer line.  Aim small, miss small.  I use no. 3's, and 4's.  2's wear down too fast.

Even when I'm framing a house, I don't use carpenters pencils for anything, and I did that for a living, for decades.

I will admit that sometimes I cheat with a digital angle gauge.  That, a sliding bevel, and a Lee Valley setting gauge, along with a set of old Stanley angle dividers, will save all sorts of time.

I'll see if I can find a link to the setting gauge.  https://www.leevalley.com/en-us/shop/tools/hand-tools/marking-and-measuring/bevels/52403-veritas-bevel-setter

[esarratt]

I will admit that sometimes I cheat with a digital angle gauge.  That, a sliding bevel, and a Lee Valley setting gauge, along with a set of old Stanley angle dividers, will save all sorts of time.

I'll see if I can find a link to the setting gauge.  https://www.leevalley.com/en-us/shop/tools/hand-tools/marking-and-measuring/bevels/52403-veritas-bevel-setter

I realize it is a bit belated, but...

Is this what you meant by a digital angle gauge?


 
Is this what you meant by a sliding bevel?


 
Is this a Lee Valley setting gauge?


 
My background is not carpentry.  I am learning a lot as I go.

Thank you for your help.

[esarratt]

What is a good price for an old set of Stanley angle dividers?

I am seeing them for $100 to $150.

Or should I wait and watch for something to come along in the $30-$50 range?



 

[Tom King]

I saw your PM, but answered here in case it does anyone else any good.

Yes to first three questions.  My angle cube is a Wixey.  I use it to set the blade tilt on a table saw too.

I don't know of another angle divider.  I've probably had mine, just like that, for 45 years, but I wouldn't want to be without it.  That seems like a high price, but what isn't these days. I have no idea what I paid for mine new.  I don't know if there are knockoffs made now, but wouldn't be surprised.

Google angle divider, and see what you come up with.

[esarratt]

Thanks!