Owner's manual

92 — ITI SHEET METAL/HVAC PRO
Irregular Hip/Valley and Jack Rafters — Descending, with
On-Center Spacing Maintained
You’re working with a 7/12 Pitch and half your overall Span is 4
Feet. The Irregular Pitch is 8/12, and 16-Inch On-Center spacing is
maintained on both sides. Complete the following steps:
(1) Find the length of the Common rafter;
(2) Reset calculator to 16-Inch On-Center spacing;
(3) Enter the Irregular Pitch; find the length of the adjoining
“Irregular” Hip (or Valley) and the cut angles;
(4) Find the Jack lengths on the “Irregular” Pitch side (16-Inch
On-Center spacing);
(5) Find the cut angles;
(6) Find the Jack lengths on the “Regular” Pitch side (16-Inch
On-Center spacing);
(7) Find the cut angles.
KEYSTROKE DISPLAY
1. Find Common rafter length:
oo 0.
7ip PTCH 7
INCH
4fR X4FEET 0 INCH
d R4FEET 7-9/16 INCH
2. Enter On-Center spacing:
16ij JKOC 16 INCH
3. Find Irregular Hip/Valley rafter length and cut angles:
8iÇH IPCH 8 INCH
H IH/V 5 FEET 9-11/16 INCH
H PLMB 23.70162°
H LEVL 66.29838°
H CHK1 41.18592°
H CHK2 48.81408°
4. Find Irregular Jack lengths:
Çj IJOC 16 INCH
j* IJ1 2 FEET 9-5/8 INCH
j IJ2 1 FEET 4-13/16 INCH
j IJ3 0 FEET 0 INCH
*Note: It is not necessary to continue pressing Ç when displaying each Jack rafter
size.
(Cont’d)
STORED