anyone out there use the secant method ?
arnemckinley
| Posted in General Discussion on
anyone out there use the secant method, as opppsed to “stepping”, or the pythagorean theorem, when roof framing. if so what do you find are the advantages?
Replies
What exactly is the SECANT METHOD? I have never heard of it before.
the secant shows the realationship of the rafter divided by the run. it's a number, if multiplied by the run, = the rafter length.
Edited 2/1/2007 9:05 pm ET by arnemckinley
Where were you during trig class?
sine, cosine, tangent, cotangent, secant, cosecant ... and that's about all I remember.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I was smoking a joint. :-)
Look on your framing square.
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
You have to know that the differance between a framing square and a speed square and many young carps don't. They have no clue as to what the scales on the square can do for them.
I have to admit that since the advent of the CM calculators my square doesn't get the use it did in the past, but I still use it enough to remember how it works.
Didn't work for me- I have 5 kids!
Baseboard been VERRRY good to me
You can build a gable roof without any trial and error. Done it many times, but then no one builds a gable roof with rafters anymore.
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
but then no one builds a gable roof with rafters anymore.
???????? You need to get out more. I must have framed at least 30 gable roofs last year alone.... all with rafters.View Image
Even I stickframed gables last year. And I am a truss guy.
Well, of course I was drastically over generalizing. Glad to hear you're doing it! It was always one of the most satisfying parts of framing for me.
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
True dat. It's usually my favorite part.View Image
how about a thread on using those methods for us new carps wnating to learn?"it aint the work I mind,
It's the feeling of falling further behind."Bozini Latini
Last year I posted about how to use the framing square to do your taxes. Really. : )
"Last year I posted about how to use the framing square to do your taxes."
Thanks for posting that - It saved me a bundle last year.
Are ya gonna update it for the new tax codes this year ???
Support your local undertaker - drop dead.
The most up to date version is the Swanson Framing Wizard...sounds like it might do your taxes for you...but if you want to get you return faster try using the Speed Square. ; )
I'm not sure if it's exactly what you're talking about, but I use tangents all the time when roof framing, or laying anything out with angles. Tangent is the same relationship as rise/run, so it's easy to go back and forth with common roof pitch angles.
I've got the table of tangents written down in one or two places in my paperwork that is always with me, as well as a scientific calculator that I carry.
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
secant just changes things up a little bit. i myself use the pythagorean theorem. the secant method is used if an angle is shown in degrees, you don't know the rise so the pythagorean theorem won't help. it can be figured out and finding the secant and using is a quick and accurate method of calculating the rafter length. in this case.
this wasn't a question on how to use my square, though i agree with dovetail that many of the new guys coming up don't see the point in learning the tricky math or what all those weird number scales on a framing square are. LOL
thnks for your reply
There are a couple of shortcuts that I think are worth remembering.Like a 3-4-5 triangle is the same as a 9/12 pitch. The slope length (5) is 1.25 times the horiznotal length (4). That can be handy for estimating roofing sometimes. At a 5/12 pitch, the slope length is 13 where the horizontal run is 12. Again, that can be handy for guestimating something in your head. On a 6/12 hip roof, the hip rafter length is 1.5 times the length of a common rafter.
I think the aliens forgot to remove your anal probe.
Hey, I looked and there really are some weird numbers on this square.
huhh????what?????
I haven't done any serious roof framing in years, but when I did, I used trig for all my figuring. It just seemed easier to me, at the time. I started with the CM calculator, but once I converted to a trig calculator, I found I didn't have much use for the CM. Used to figure some pretty cut-up multiple hip and broken valley roofs, and pre-cut my entire roof before beginning to stack. Now, I'd have to clear out some serious cobwebs to do another one.
"Down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid...He must be, to use a rather weathered phrase, a man of honor, by instinct, by inevitability, without thought of it, and certainly without saying it." - Raymond Chandler
arne.. i started out stepping with my square & buttons
then when trig calculators became fairly common ( what ... early '80's ? )
i figured all my rafters & diagonals with trig.. usually SOHCAHTOA
then i got a CM : Trig Plus III and i use that almost exclsivelyMike Smith Rhode Island : Design / Build / Repair / Restore
Unfortunately most guys prefer the cantsee method, as in "can't see it from my house"
Mike
Trust in God, but row away from the rocks.
that was`witty good one-----------------------------------------------------------------------------
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