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Looking for Hucks 4x4 roof cuttin lesson

MattSwanger's picture

im looking for that article and cant for the life of me find it,  i wanted to read it and try to work it out in my own hands/head. 


anyone have a link or a name of the article?


Woods favorite carpenter


 

Woods favorite carpenter

(post #108898, reply #31 of 322)

Joe - here is a sketch showing how the model relates to the actual roof.  Maybe it'll help you visualize what I'm trying to accomplish with the model. 


You can see that line 6 is a common rafter, line 5 is a hip rafter, angle A is the roof pitch, line 2 is the run of the roof, line 3 is the fascia, and line 4 represents the fascia miter cut.





Edited 9/20/2009 1:08 am by Huck

(post #108898, reply #32 of 322)

and here's the sketchup model


(post #108898, reply #33 of 322)

Huck,

I really didn't have trouble understanding the model, but thanks for taking the time to post the SU file. The focus of my comments were more on the labeling of the model, not the model itself.

(post #108898, reply #35 of 322)

"he focus of my comments were more on the labeling of the model, not the model itself."

That was my problem too. If each leg or hypotenuse was labeled with a unit number, I'd quickly be able to understand it.

Is anybody out there? 

(post #108898, reply #36 of 322)

Jim,

When I read your post here in this post is when I went back and looked at the model. I remember the first time Huck had posted this and, in all honesty I just glanced over it at the time. On a whole I think it's pretty cool ;-).

There are two angles that are just not jumping out though, the hip miter angle and the saw bevel angle. I located the hip miter, but it doesn't appear to be in a useful place to use and I just don't see the saw bevel angle.

If anyone knows where it is or how to construct it in the model, that would be very useful.


Edited 9/20/2009 10:07 am ET by Joe

(post #108898, reply #37 of 322)

I think it's very cool. He's 3/4 done if he wants it to be a valid lesson tool. A few more labels and it would easily make sense to anyone that has actually cut a roof.

Is anybody out there? 

(post #108898, reply #38 of 322)

The way I see it, Huck is applying jack miters, or plan view angles/bevels, to a plumb line drawn on a plumb face of a block (representing the side of a Jack).  The roof plane (top, or end grain) and the fascia plane (non plumb remaining side) are represented by existing sides of the block.  Therefore, to solve for Irregulars, the reciprocal bevels need to be applied as you would for the jack rafters.


 


The first time I saw it I also only glanced at it without any semi-serious analysis too.  Once it snaps in though, it’s simplistic coolness is revealed.   I like easy!

(post #108898, reply #39 of 322)

Mr Jalapeno ;-)

I really don't think this is or, even is, easier than using a square to draw it out on a piece of plywood. It's just another way of representing the information, and as we all know, there are many. . .

The initial premise is to draw the "angle" for which you need some instrument to do so. If that instrument should be a speed or framing square it might just be simpler to lay it out on a piece of plywood. That's just one roof cutters opinion though.

(post #108898, reply #40 of 322)

I believe Huck said he uses his saw as the bevel finder on his model.  And that’s how I do it too.

(post #108898, reply #41 of 322)

You may have misinterpreted my question. Where is the bevel you place against your saw to find out what the bevel is. . .

(post #108898, reply #42 of 322)

Joe,


Huck’s model is a tetrahedron consisting of three faces with a 90 deg corner and the third side created by cutting the plumb line at the (a) plan angle.  It is the only non right angle side (face) that has three perpendicular lines that can be drawn off the edges into the corners (angles).  These 90 deg lines will meet the other three faces with single 90 deg lines from their bevel edges to the right angle corner.  The tetrahedron has 6 possible bevels and we already know 4 of them, 3 at 90 and one at the plan angle. (Using Huck’s most recent illustration in post 32) The angle pivoting the saw across the top, (line 5) is the hip backing angle, and the angle pivoting along line 4 is the square run fascia miter.  And like he says, you don’t even need to know what the angles are, just set your saw against the model.


 


Is that the answer to your question?

(post #108898, reply #43 of 322)

You're right, it is a tetrahedron.  Once that's understood, its easier to see that the angle of the fascia bevel is right there, where the two planes meet along the edge of line 4.


click for a larger image


I'll elaborate more on Joe's and others' questions when I get a little more time - I'm on the run right now and gotta go.


I'm gonna try and make a video to explain a few things - maybe this evening.


(post #108898, reply #44 of 322)

Richard,

Thanks for such an astute explanation. . . To bad you failed to answer my "simple" question; where are the hip miter and the saw bevel angle to cut both the hip and fascia miters?

I know what they are and what they measure, just would like to know where they are on the "tetrahedron." You seem to answer like to know, but like a hoard don't want to tell the rest of the toads in the pond know;-)


Edited 9/20/2009 8:18 pm ET by Joe

(post #108898, reply #45 of 322)

You're not the only one having a hard time figuring this out, Joe.  If I can figure one angle, I can figure the rest and not sure I'd have a need for the extra aid of the 4x4  block. 


Now, if Huck can layout the 4x4 without using anything but a tape measure I'd be a LOT more interested. 


 

(post #108898, reply #48 of 322)

John,

The model wasn't that hard to understand and for what it is, it's pretty interesting. The trouble I had was with its labeling. The answer; "that if I understood the model I'd get it" just was going to far for me.

The only thing that this model has provided so far that would be slightly out of the ordanary was the hip backing and fascia miter angle, which don't get me wrong are a good things to know, but the other two angles are of equal if not, greater importance. If it's not easy to find them then the model just falls short in my estimation.

(post #108898, reply #49 of 322)

I'm anxious to see his video explaining it.

Is anybody out there? 

(post #108898, reply #50 of 322)

The only thing that this model has provided so far that would be slightly out of the ordanary was the hip backing and fascia miter angle, which don't get me wrong are a good things to know, but the other two angles are of equal if not, greater importance. If it's not easy to find them then the model just falls short in my estimation.


Joe - as far as I know, every angle in a hip roof is in the model.  I don't think any of them are hard to find, but maybe that's just me.  Here's a photo showing the fascia miter angle.



 

And here's another method

 


 

 


Edited 9/20/2009 8:53 pm by Huck

(post #108898, reply #51 of 322)

Here's a photo showing finding the hip or valley backing angle



(post #108898, reply #59 of 322)

Huck,

I'm not trying to be obtuse here but, I keep telling you that you (or anyone else) need to show "where" the "two" other angles are. Once again you are "missing" the hip miter and the saw bevel to cut both the hip miter and the fascia miter.

The fascia miter you show is only good for "laying out" the the cut on the fascia. It is the line you'd follow when you make the cut. The saw would need to be set to the saw bevel angle. The other angle is the hip miter which is also a line you'd follow while making the cut with the saw set to the saw bevel angle.

(post #108898, reply #70 of 322)

I'm not trying to be obtuse here that's ok Joe, it comes natural to some people =)  but, I keep telling you that you (or anyone else) need to show "where" the "two" other angles are. Once again you are "missing" the hip miter and the saw bevel to cut both the hip miter and the fascia miter.


The fascia miter you show is only good for "laying out" the the cut on the fascia. It is the line you'd follow when you make the cut. The saw would need to be set to the saw bevel angle. The other angle is the hip miter which is also a line you'd follow while making the cut with the saw set to the saw bevel angle.


now pay attention: the angle you mark on the fascia to cut the miter



 

the angle you set the saw at

 


 

or just set the block of wood on the saw's base plate, and rotate the blade until it's tight, and that will leave the blade set at the proper bevel angle...

 


(post #108898, reply #75 of 322)

Huck,

"Well again it all right here."That's what you said in your video. If you are measuring that angle, the one in the video and the one in this picture, it's not the correct angle to set your saw blade at. If I measure that angle (I think I got the right one and measured it correctly) in your model it comes out to ~55° or its complement of ~35° whichever you prefer.

Also you still haven't shown where or how to get the hip miter as well.

(post #108898, reply #88 of 322)

"Well again it all right here."That's what you said in your video. If you are measuring that angle, the one in the video and the one in this picture, it's not the correct angle to set your saw blade at. If I measure that angle (I think I got the right one and measured it correctly) in your model it comes out to ~55° or its complement of ~35° whichever you prefer.


Joe - You either didn't get the correct angle, or didn't measure correctly, it is the correct angle, and its not 55 or 35 degrees.  Its actually very close to 39 degrees.  (I have the exact angle, but not an exact tool to measure it).


Also you still haven't shown where or how to get the hip miter as well.


Hip miter?  What is that?  Where does the hip miter into anything?  At the top, the plumb cut on a 6:12 hip is 6:17, the saw bevel is set at 45 degrees.  At the bottom, it dies into the fascia, and I explained how to get those angles.


Do you want to understand the model, or just trying to find fault with it?  I ask, because it feels like the latter, although I keep answering your criticisms hoping its the former.


edited to correct an error in describing the angle of the miter fascia bevel - thanks Joe!



Edited 9/21/2009 12:01 pm by Huck

(post #108898, reply #52 of 322)

if Huck can layout the 4x4 without using anything but a tape measure I'd be a LOT more interested.


I never know when you guys are joking or not.  All you need to lay this out is the angle of the roof pitch, and a square. 


To lay out the angle of a 5:12 roof pitch "without using anything but a tape measure", measure 5" along one leg of a right angle, and 12" along the other edge.  Now, connect the lines, and you've  got a 5:12 roof pitch angle.


Of course, if you really didn't know that, then this discussion is probably well beyond your capabilities at this point anyway.  =)


(post #108898, reply #56 of 322)

>", measure 5" along one leg of a right angle, and 12"<


then you wouldn't be using a 4x4 then would you?  If I got a square I can get the rest.  I usually have 2 or more squares set up when do roof framing.


Next time I get some spare time I'll fiddle with your SU model and compare it to the same cuts I'd make on the rafters. 


I'm not banging on you, Huck. I figure we're always joking so that way none of us gets our panties in a wad. 


Edited 9/20/2009 9:23 pm ET by john7g

(post #108898, reply #57 of 322)

I figure we're always joking so that way none of us gets our panties in a wad. 


OK, fair enough.  I just figured that any framer worth his salt could mark a roof angle - the angle of a plumb cut on a common rafter.  I learned to do that within a few months of beginning in the trade, 30 years ago.  That's the basis for my model.  If you can do that, you can get all the angles in a hip roof with this jig.  If you need someone to show you how to do that, then this jig won't help you anyway.


(post #108898, reply #46 of 322)

Ask an "astute" question, and.... I know, i should have posted the link to your calculator for you....  next time man.

(post #108898, reply #47 of 322)

Richard,

You seem like a dancing bear with neither a partner or an answer.

(post #108898, reply #53 of 322)

The way I see it, Huck is applying jack miters, or plan view angles/bevels, to a plumb line drawn on a plumb face of a block (representing the side of a Jack).  The roof plane (top, or end grain) and the fascia plane (non plumb remaining side) are represented by existing sides of the block.  Therefore, to solve for Irregulars, the reciprocal bevels need to be applied as you would for the jack rafters.


The first time I saw it I also only glanced at it without any semi-serious analysis too.  Once it snaps in though, it’s simplistic coolness is revealed.   I like easy!


Mr. J:  Glad to see you get it!  Once you see how the model (or jig) relates to the roof itself, then you see that all the angles are there, and you can find them.  The angle of the roof pitch, which would be the plumb cut on a common rafter, is all you need to do this.  With that, you get the plumb cut of the hip/valley, the rafter cut for a square-cut fascia (which is not square on the hip/valley), the compound angle miter cut for the fascia, the backing angles, the sheathing angle, and so forth.


(post #108898, reply #54 of 322)

If it's so easy, why not make it easier by labeling each of them?

Is anybody out there? 

(post #108898, reply #58 of 322)

If it's so easy, why not make it easier by labeling each of them?