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Calculated Industries 4065 v3.1 User Guide User Manual

Page 72

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64 — C

ONSTRUCTION

M

ASTER

®

P

RO

/ T

RIG

/ D

ESKTOP

Irregular Hip/Valley and Jack Rafters —

Ascending, with Jacks

Mating at Hip/Valley

You’re working with a 7/12 Pitch and half your overall span is 4 Feet.
The Irregular Pitch is 8/12, and the Jacks need to mate at the Hip.
The maximum allowable On-center spacing is 16 Inches. Find the
Jack rafter sizes from smallest to largest (ascending order).
Complete the following steps:

(1) Set Preference display to “JK ASCEND” (Jack sizes in

ascending order);

(2) Set Preference display to “IRJK JAC-JAC” (Jacks mate);
(3) Find the length of the common rafter;
(4) Find the length of the adjoining “Irregular” Hip (or Valley) and

the cut angles;

(5) Find the o.c., incremental jack adjustment, Jack lengths and

cut angles on the “Irregular” pitched side;

(6) Find the o.c., incremental jack adjustment, Jack lengths and

cut angles on the “Regular” pitched side.

Note: After completing this example, you may need to reset the Preferences back to
“IRJK OC-OC” if you do not normally figure jacks in this manner. (See Preference
Settings on page 83.)

KEYSTROKE

DISPLAY

1. Review Preferences until you find “Jack Descend”:

o o

0.

З Я

(Prefs)

FRAC 0-1/16

INCH

(If not at 1/16, press

+

until 1/16 is displayed)

ß

AREA Std.

ß

VOL Std.

ß

HDRM 6

FEET

8

INCH

ß

RAKE dESCEnd

ß

AW outSidE

ß

JACK dESCEnd

Set Preference to “Ascend”:

+

(plus sign)

JACK ASCEnd

2. Set Preference to “Jacks Mate”:

ß

IRJK OC-OC

+

(plus sign)

IRJK JAC-JAC

3. Find common rafter length:

7 i p

PTCH 7

INCH

4 f R

RUN 4

FEET

0

INCH

d

DIAG 4

FEET

7-9/16

INCH

(Cont’d)

This manual is related to the following products: