# Finding X leg angles



## PhillipRCW (Dec 9, 2014)

Has anyone worked with any online tools to help determine the correct angles of X legs? I was hoping to find something, but have so far not found anything worth while.


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## darinS (Jul 20, 2010)

Phillip,

Would something like one of these work for you? I would think it would just be trigonometry unless I am misunderstanding what you are trying to do.

http://www.calculatorsoup.com/calculators/trigonometry/


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## wormil (Nov 19, 2011)

There was a big discussion about this, maybe 2 years ago. The math is deceptively complex. Seems like it should be simple but isn't. The easiest ways are a drawing program or laying them out full size.


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## PhillipRCW (Dec 9, 2014)

> There was a big discussion about this, maybe 2 years ago. The math is deceptively complex. Seems like it should be simple but isn t. The easiest ways are a drawing program or laying them out full size.
> 
> - Rick M


Yeah, I love math, but it can definitely get crazy.


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## DirtyMike (Dec 6, 2015)

I Just use 2 scrap 2×4s, measure the width of table top and scribe 2 lines. Defiantly a measure twice cut once situation.


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## 000 (Dec 9, 2015)

The math is over my head, Sketchup, it only takes a few minutes.
I did find this, (if it works) There is a calculator on the right side you can try.
http://jsfiddle.net/h1xda7qm/


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## mojapitt (Dec 31, 2011)

On the table I am building, I didn't do any math. I laid them with my desired height and span, marked them. Worked for me anyway.


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## PhillipRCW (Dec 9, 2014)

> On the table I am building, I didn t do any math. I laid them with my desired height and span, marked them. Worked for me anyway.
> 
> - Monte Pittman


Any pictures of the current work Monte?


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## 000 (Dec 9, 2015)

Is this not what you are looking for? ( http://jsfiddle.net/h1xda7qm/ )
If not, what are you trying to find?


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## diverlloyd (Apr 25, 2013)

The math is easier to understand if you realize that it's for making a triangle and the board is the hypotenuse of said triangle. After that you can use a calculator and use the rise and run function of it. Instead of having to use the sin and cos buttons which are confusing with out knowing the formulas.


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## wormil (Nov 19, 2011)

Show us Lloyd.


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## diverlloyd (Apr 25, 2013)

Jbays pic shows what I'm saying all he is doing is making a triangle with rise and run and the board is the hypotenuse. So on a calculator( I use a sheet metal union calculator but any with a rise and run function will work) you punch the rise and run in and then it gives the length and degree of hypotenuse. Just remember that a triangle has 180 degrees in it. So doing cross bracing your run will be the length between the legs and the rise will be height you putting the brace. So that should be a 90 degree unless your legs are canted we will stay with 90 for the ease of my long explanation. Now 180 - 90 is 90 so your bracing angle cuts should add up to 90. So as in jbays pic the angle is 44.768 degrees so 90 minus that is the angle of the cut used on the bottom to make it flat. Since it's a right triangle both ends would be the same. Most of the guys in my class had issues with the same thing because they looked at it as being a square but it's really just a couple triangles making the math a bit easier. I'm not going into sine cosine because it's confusing and you need to use the memory function on the calc and then you need to know the difference of 0 off 90 and 90 off 0. That really confused my class mates I like math and that is just a pain and if you don't do it often you forget the steps. It's easier to show it in person then explain it in words but if your calculator doesn't have the function just use and internet site that has a plug in. You can brake anything down into a triangle like that to make the math easier once you get used to doing it. I just made a 3ft cut out of Indiana for a client and used the same method of triangulate all the points of the bottom of Indiana to make it accurate. But with that I used two triangles and the used the points where the two hypotenuses met for the points.so now I have all the point measurements I can make another of any size by just using a size ratio. Sounds more complicated then the bracing but it's the exact same thing just done twice to find a point minus the extra step of the degree cut. Triangles are good for lots of different lay out of shapes. I have three of the sheet metal union calculators that I use and they are the same as the construction calculators you see at the store but they have more hvac features.
That being said Monte has the easiest method for doing braces.


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## diverlloyd (Apr 25, 2013)

A guess a pic(jbays) is worth a thousand words sorry I started rambling


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## wormil (Nov 19, 2011)

My question wasn't, 'how did jbay do it?' Give people some credit. I realize it requires trig to solve and I know why. I wanted to know how you did it with a rise and run calculator because the simple ones I've seen won't do cross bracing but I searched around and found a $70 one that will. The only cross braced table I ever built, I tacked the legs together with a nail, made them to the right width and marked the angle, whatever it was. No measuring, no math, no cadd.


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## diverlloyd (Apr 25, 2013)

With a rise and run calcutlator you put in the rise and then the run the hit the hyp button. That gives you length hit hyp again and it gives you the angle. I guess I gave you to much credit thinking you read the manual with you calculator. So i gave the process with my calc what calc do you have?


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## 000 (Dec 9, 2015)

"any *online tools* to help determine the correct angles of X legs?"

^Just for the record, all I was doing was showing the OP what I thought he was asking for.

These days Sketchup would be MY preferred method.
In the past I have done it many other ways, methods as described by Monte, to full scale drawings.
(I never was good with formulas.)


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## wormil (Nov 19, 2011)

> With a rise and run calcutlator you put in the rise and then the run the hit the hyp button. That gives you length hit hyp again and it gives you the angle. I guess I gave you to much credit thinking you read the manual with you calculator. So i gave the process with my calc what calc do you have?
> 
> - diverlloyd


It wasn't my intention to argue with you, I was just trying to understand how you were doing it with nothing more than rise and run.

When you change the leg width, it changes the angles, so you have to input leg (brace) width or you won't get the right answer. You are calculating a brace where the ends are perpendicular but on a table the ends of the legs are parallel.


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## diverlloyd (Apr 25, 2013)

My bad I failed to mention the most important thing don't hit the equal sign on those style calculator and the hyp and angles are still the same but the reference line is different which is from opposite corners of the brace so the angles are off that line not the edge of the board. Sorry that slipped my mind. I can take pics whenever I get home if you want. It's easier to show then type as I missed some stuff.

I was giving other options besides the internet.


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## PhillipRCW (Dec 9, 2014)

Thanks everyone. I'm still lacking in my sketchup skills, but it sounds like I might just need to pick it up. My phone hates me currently so I can't upload the pictures, but I want to some modern looking tables where the breadboard end is also the top of the x leg. Also wanting to do some MCM bases for cabinets and bookcases.


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## mojapitt (Dec 31, 2011)

> On the table I am building, I didn t do any math. I laid them with my desired height and span, marked them. Worked for me anyway.
> 
> - Monte Pittman
> 
> ...


I haven't taken pictures of the legs yet. This is the unfinished top.


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## Verbs (Nov 29, 2020)

Hello so I just used the website( http://jsfiddle.net/h1xda7qm/ ) and it works great; however the guy above messed up with his diagram and drew it wrong.

The 44.768 degree is the mitre cut degree and not where he placed it in the pcture. That angle would be 90 degrees less the 44.768 so will equal 45.232.

To figure out the angle for where the x-intercepts you go 180 degrees less (45.232 times 2) and will equal 89.536. This is the angle the one board goes through the other board. On your mitre saw the 0 degree position is actually cutting 90 degreees or perpendicular. So the angle you need to carve out would be 90 degrees less 89.536 degrees and would equal just under 1 degree.

What I did to figure out where to cut it on the baord. I first divided the cut length by 2 and found the centre of the board. Please note this is not from out outside of the baord or against it's length but the middle. So on your 3 inch board it would be 1.5 inches to the middle, and then the cut length down to the middle of your length.


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## RetiredRonnie (Nov 7, 2021)

> Has anyone worked with any online tools to help determine the correct angles of X legs? I was hoping to find something, but have so far not found anything worth while.
> 
> - PhillipRCW


I actually built an app that does exactly this. It also gives you 5 board-end positions to choose from.


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