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Can this be done with construction master pro or do I need a scientific calculator?
The CM Pro w/Trig can be used to solve this.

I suggest copying Sim's reply over at JLC and printing it out to include in a Jobsite reference notebook. :clap:

I have not run into this very often where both sides of the Rake Wall had a common ceiling so I would usually frame it different than this. I just put a H/V rafter below the slope that was inline and plumb to the interior, or finished side, and fingered the studs to it. (Like a H/V purlin Rafter) I used this method on corner fireplaces. or over kitchen/breakfast bars with a matching ceiling line, etc.. If the angle was a 45 it was just a simple regular pitch H/V solution with the CM.


Thanks Sim, You too Ken. :thumbsup:
 

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bmartin,

I'm almost positive that it can be done on a CM pro. You would have to follow a series of steps to arrive at the answers. I may have time to work that out for you, but be patient, I'm a little busy right now.

Ken
 

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bmartin,

If you want to avoid using the trig functions, you could use your CM Pro to find answers to these types of problems. In this example, I'll use the same plate angle that the stud wall makes with the rafter plate, 67 1/2 degrees, and the same roof pitch, 12/12. Here's how to get the bevel on the top plate, for example

1) enter the plate angle that the stud wall
makes with rafter plate 67.5
2) press pitch (display shows 67.50 degrees)
3) enter 12 ( not 12" ) and press rise
4) press run (display shows 4.970563)
5) press Stor 1 (stores the result in memory 1)
6) press conv x^2 (x squared ) (display shows 24.70649)
7) add 144 and then press = (display shows 168.7065)
8) press + roof rise, in this case 12,
( not 12" ) and press conv x^2, then
press = (display shows 312.7065)
9) press conv square root x (display shows 17.68351)
10) press conv 1/x (display shows .05655)
11) multiply result by roof rise,
12, ( not 12" ) (display shows .678598)
12) press x RCL1 = (display shows 3.373016)
13) divide result by 12 then press = (display shows .281085)
14) press rise
15) press 1 = run
16) press pitch (display shows 15.70), the bevel on the top plate.

Ken
 

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My hat is off to guys like mathman and Birch. I am really good with basic math, but I do not use a calculator on a job site. Taking 16 steps to figure an angle/bevel on a wall seems time restrictive and the probability of an error is also high.

I can see using math for more critical areas, rafters, ridge, valleys, hips, etc, but for a simple non bearing wall, built in place, you can't beat a straight edge and a speed square for speed and accuracy.
 

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Warren,

I'm not necessarily recommending this method. My point was that for those people who don't understand how to use the trig functions, that there are alternatives, and to show that they can be solved using a CM calculator.

Another alternative method is do it as you recommend. Most framers would do it that way.

Personally, I like to work out the math for these type of problems at home. Then when I get to the job, I know what all of the cuts are.

ken
 
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