# Thread: Unwrapping the curve from where 2 cylinders join?

1. ## Unwrapping the curve from where 2 cylinders join?

Hello all,
I am not a student in a school but a professional that needs some math help. I am a programmer for cabinet companies. I program in a software called Cabinet Vision Solid. That is a little useless information but may help clarify somethings. I am working on a cabinet with curved sides that meet at a 90 degree angle. I have a lot of known information (parametric) but cannot figure out how to plot this 3D curve flat for manufacturing. Anyway here goes. I found an article here (http://mamikon.com/USArticles/RollingConesCylinders.pdf) that explains what I am trying to do. I have been trying to follow the steps but I don't understand the way some of the things are working together. First let me give you a picture of what I am trying to accomplish:
Curved Hood Example.JPG
(finished product)

And here is a picture of some of the knowns that I have:
https://www.dropbox.com/s/cj7i2od5wg...hinoDetail.pdf

I know everything listed in this picture and using some simple trig I know the length of the arc from the bottom to the top of the face and the side. The chords, the angle of the arcs, the height of the arcs, etc... I have a parameter that is the length of the arcs divided by 20. I figured if I can cut it into 20 segments it will be fine enough to put together. If I need to make it more not a problem. I therefore know the "y" points of the arc. I have a loop that does Y*1, Y*2, Y*3, Y*4, etc... to give me all the "y"s up the arc. What I need is a formula that I can plug this "y" value into and get the "x" or "z" value from it. Like I said above I have tried to follow the article but it is just a little over my head. For instance what formula can I put in to find the "P" of the equation in section 5? I can't find that. Whenever I try to find what they term the X by r*theta (I think) I get this HUGE number that I can't do anything with. Any help would be greatly appreciated. I am more than willing to give you any information that I can. Thanks in advance,

John

2. ## Wrong Area?

Did I post this in the wrong area? I haven't gotten one hit. Can someone please tell me where to post this question of how to get the equation to unwrap a curve off a cylinder? I really just need some help understanding some of the things in Section 5 of the paper I posted above. Thanks,

John

3. You have posted to a math tutoring forum, but your post reads like this is a real-world problem for which you're wanting an engineer to develop equations, schematics, or some other type of construction information. It's possible that the issue is that you're asking math volunteers to be free contractors. Besides (probably) many (most?) of us not being qualified, what you seem to be asking is not what this site does.

You may have to hire somebody to obtain the services you seek.

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