Need help from someone good with math or whatever this is lol

I know I'm not good at this kind of stuff and figures someone could help me get this right the first time I'm making a rack for my truck..

Uprights are 16" the top span is 48" and the bottom needs to be 59" from end to end here is a bad picture to illustrate



I want it bent and do not have a bender so going to drop it off at a friends and have to give him want angles how would I explain this to him and what angle would that be to get the measurements all where I need them? I could do this on my own if I was just welding it but I want bends and they are making me feel stupid cause I can't figure out how to explain this in a simple way..

 

Find a drafting program, it will do the hard stuff for you

 

If no one helps with this, I can see if I can whip something out for ya, also, are your measurement all from the inside of the tube? Which size tubing are you running? And any idea what radius his bender is?

 

I don't have a computer to run any program on.. Could not find one I could work on my phone the 16 " vertical is from my cut on the bottom to the middle the top 48" is from the middle of the bends and bottom is from middle to middle .. So middle? Lol
Going to be using 1-1/4 sch 40 and no I do not know the radius of his bender

 

So you want the inside angles of the trapazoid you drew???

 

Yes? I think. I wish I paid attention in school now..

 

Thank you!

 

Very good.

 

Hey Guitarman, does your program take into account bend radius? I just did a quick calculation on a napkin and the 110 degree inner angle is a smaller angle than my quick geometry calculation.

Here's what I did: (correct me if I went wrong!)

Split the trapezoid into a rectangle and two right angle triangles (on either side). The base leg of the triangle is 11" (59-48), the hypotenuse is 16.

To calculate the interior angle of the bend I set the sin of that angle equal to the opposite leg (11) over your hypotenuse (16). 11/16=.6875 so sin^-1 of .6875 equals 43.4 degrees. Finally I added that to the 90 interior angle of the rectangle coming up with 133.4 degrees.

Looking at your 110 vs my 133, it would make sense to me that yours accounts for bend radius. How did you pick the radius to use?

 

All looks well except for your base dimension, there are two triangles (one on each end) so you have to divide by 2:

59"-48" = 11"
11"/2 = 5.5"

X =Sin ^-1 (5.5/16) = 110°

My program doesn't account in for bending radii, I just assumed a 2" radius. These numbers are a little more precise than one could get bending a piece of 1-1/4" tubing so there should be no issues.

 

DOH! (I am officially an idiot) Man, I knew something just didn't seem right. Thanks for setting me straight!

 

Thank god for prograns like solid works for stuff like that!

 

And in real life, those degrees get you really close, then real life sets in...

 

Yeah I just needed close the bender can't be exact anyways thanks everyone for all the great help with your fancy math lol

 

Just when I did all the math and figured it out....

 

good thing I decided to scroll down....almost did the math out on this one.

 

Luckily the math isn't too intensive! I used AutoCAD and drafted it out in under a minute - double checked it with hand calculations. Can never be too sure and I sure as hell will NEVER 100% trust any answer the computer spits out.

 

You guys are awesome lol I will get pictures wed. When all 3 are bent... I can't wait to get this on my truck and add my Jerry cans hi-lift and spare tire mount... That will all be empty till I have money lol

 

Sadly, I looked at this and was like

Even though I had college level (intro) calculus, and stats, and trig and crap, I stopped understanding math about the time we introduced letters. You know, like 7th grade.

I firmly believe all the math I need to know for life stopped in 4th grade.