SBE Builders

Strong Built Establishments Builders

SBE Builders is a commercial and residential framing contractor located in Discovery Bay California. Dedicated to the art of Carpentery & Roof Framing. We are the professionals for the future of the craft of carpentry.

Hopper Miter Angle and Saw Blade Bevel Angle Settings Development

Hopper with 52° slope angle


Hopper Miter and Saw Bevel Angles Calculator

Hopper angles are the same angles that are use for cutting roof sheathing. The hopper miter angle is the same as the jack rafter side cut angle and the hopper saw blade bevel angle is the same as the hip rafter backing angle. The crown spring angle is measured on a vertical plane. The hopper slope angle is measured on a horizontal plane.

Hopper Slope Angle


Roof Pitch Angle = Hopper Slope Angle

Use any of these formulas to find the Hopper Miter Angle
Hopper Miter Angle = arccos( sin ( Plan Angle ) ÷ cos ( Hip Rafter Backing Angle ))
Hopper Miter Angle = arccos( sin ( Hip Rafter Angle ) ÷ sin ( Roof Pitch Angle ))
Hopper Miter Angle = arcsin ( cos ( Plan Angle ) × cos ( Hip Rafter Angle ))
Hopper Miter Angle = arcsin ( tan ( Hip Rafter Backing Angle ) ÷ tan ( Roof Pitch Angle ))
Hopper Miter Angle = arctan( cos ( Roof Pitch Angle ) ÷ tan ( Plan Angle ))
Hopper Miter Angle = arctan( sin ( Hip Rafter Backing Angle ) ÷ tan ( Hip Rafter Angle ))

Use any of these formulas to find the Hopper Saw Blade Bevel Angle
Hopper Saw Blade Bevel Angle = arccos( sin ( Plan Angle ) ÷ cos ( Jack Rafter Side Cut Angle ))
Hopper Saw Blade Bevel Angle = arccos( cos ( Roof Pitch Angle ) ÷ cos ( Hip Rafter Angle ))
Hopper Saw Blade Bevel Angle = arcsin ( sin ( Roof Pitch Angle ) × cos ( Plan Angle ))
Hopper Saw Blade Bevel Angle = arcsin ( tan ( Jack Rafter Side Cut Angle ) × tan ( Hip Rafter Angle ))
Hopper Saw Blade Bevel Angle = arctan( tan ( Roof Pitch Angle ) × sin ( Jack Rafter Side Cut Angle ))
Hopper Saw Blade Bevel Angle = arctan( sin ( Hip Rafter Angle ) ÷ tan ( Plan Angle ))


Hopper Miter Angle = arctan (cos(Roof Pitch Angle) ÷ tan (Plan Angle))
Hopper Saw Blade Bevel Angle = arctan( sin ( Hip Rafter Angle ) ÷ tan ( Plan Angle ))
example:
Roof Pitch Angle = 38°
Wall Angle = 90°
Plan Angle = 45°
Hip Rafter Angle = arctan( tan ( 38° ) × sin ( 45 )) = 28.91856°

Hopper Miter Angle = arctan (cos( 38° ) ÷ tan( 45° )) = 38.23849°
Hopper Saw Blade Bevel Angle = arctan( sin( 28.91856° ) ÷ tan( 45° )) = 25.80683°

or
Hopper Miter Angle = arctan (cos(Roof Pitch Angle) ÷ tan (Plan Angle))
Hopper Saw Blade Bevel Angle = arccos( sin ( Plan Angle ) ÷ cos ( Hopper Miter Angle ))
Hopper Miter Angle = arctan (cos( 38° ) ÷ tan( 45° )) = 38.23849°
Hopper Saw Blade Bevel Angle = arccos( sin( 45° ) ÷ cos( 38.23849° )) = 25.80683°


Polygon table with hopper base and IPE decking table top. All of the lumber used for this table were left overs from different jobs.

Polygon Hopper Table


Martindale's Bin and Hopper Angles Case Study 3
Bevel angles for three dimensional connections: Tapered bin, hopper & tower corner angles : hip and valley roof framing connections : analytic proof of ... of hip & valley bevel connection angles


Martindale's Bin and Hopper Angles Case Study PDF file

Side A

Side D

 


 

SIDE D
PITCH S = 8:12
S = 33.69007°
D1 = arctan(tan(S) ÷ tan(S)) = 45°
R1 = arctan(tan(S) * sin(D1)) = 25.23940°
P2 = arctan(cos(S) ÷ tan(D1)) = 39.76216°
C5 = arctan(sin(R1) ÷ tan(D1)) = 23.09347°

S = 33.69007°
D2 = arctan(tan(SS) ÷ tan(S)) = 64.98310°
R1 = arctan(tan(S) * sin(D2)) = 31.13710°
P2 = arctan(cos(S) ÷ tan(D2)) = 21.22071°
C5 = arctan(sin(R1) ÷ tan(D2)) = 13.56656°

 

SIDE A
Run = 3.5
Rise = tan(33.69007) * 7.5 = 5
SS = arctan( 5 / 3.5) = 55.00798°
D2 = arctan(tan(SS) ÷ tan(S)) = 64.9831°
D22 = arctan(tan(S) ÷ tan(SS)) = 25.0169°
R1 = arctan(tan(SS) * sin(D22)) = 31.13711°
P2 = arctan(cos(SS) ÷ tan(D22)) = 50.86232°
C5 = arctan(sin(R1) ÷ tan(D22)) = 47.93405°

 
SIDE C
PITCH S = 8:12
S = 33.69007°
DD1 = arctan(tan(S) ÷ tan(S)) = 45°
R1 = arctan(tan(S) * sin(DD1)) = 25.23940°
P2 = arctan(cos(S) ÷ tan(DD1)) = 39.76216°
C5 = arctan(sin(R1) ÷ tan(DD1)) = 23.09347°
 

SIDE B
SS = 55.00798°
D22 = arctan(tan(S) ÷ tan(SS)) = 25.0169°
R1 = arctan(tan(SS) * sin(D22)) = 31.13711°
P2 = arctan(cos(SS) ÷ tan(D22)) = 50.86232°
C5 = arctan(sin(R1) ÷ tan(D22)) = 47.93405°

SS = 55.00798°
D1 = arctan(tan(sS) ÷ tan(SS)) = 45.00°
R1 = arctan(tan(SS) * sin(D1)) = 45.28938°
P2 = arctan(cos(SS) ÷ tan(D1)) =29.83265°
C5 = arctan(sin(R1) ÷ tan(D1)) = 35.40023°

 




Hopper Miter and Saw Bevel Angles Calculator


  
  
SBE Builders
SBE Builders


Holy Grail of Roof Framing Geometry & Trigonometry

Book I & Book II. These roof framing books were written to make complex roof framing simple..

The Art of the Line for Carpentry

The book includes step by step instructions on developing stereotomic drawings on Art du Trait de Charpente, Trestles, Tréteau à devers, Canted Trestles, Louis Mozerolles' Joiners Table, Sawhorses, and the Saint Andrews' Cross, twisted crosses. You'll also find theories on hip rafter shift-offset, standard roof framing kernel trait drawings, German Schiften DP-Shadow Line techniques, folding net roof surface and net plane geometric development, when hip rafters collide, the Warlock Cut, and developing upper and lower claws on rafters using Axioms.

HG IV Circular Work in Carpentry

The book includes step-by-step instructions on developing stereotomic double curvature drawings for circular work in carpentry. Some of the techniques presented in this book are thousands of years in the making. As carpenters, we shouldn't have to re-invent the wheel each time we are faced with new challenges. There is a likely hood that someone, that came before us, has already refined a technique that we can use today. The tools might have changed, but the piece of wood that it is twisting and turning remains the same piece of wood.

Rafter Tools+ for iPhone

Rafter Tools+ is a rafter calculator for complex roof framing angles that other roof framing calculators don't offer.

RafterTools+

Stair Tangent for iPhone

This iPhone app is for rough frame carpenters that don't build stairs everyday, but could use an stair app calculator to check their stair building calculations.
Build a set of stairs that you are gonna be proud of.
With Stair Tangent you can elimenate cumulative math errors when building - constructing stairs.

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