Parabolic dish

[Naylor]

Good day,

I am currently creating a parabolic dish from six sixty degree petals/segments. However I cant seem to get the correct flat pattern of such a segment. I created a pizza slice type flat pattern, but this created gaps in my dish. I realised I had to create a triangular shape with arcs of certain radii on all three edges but have no idea how to get this shape's geometry?
Any help will be appreciated.

 

[rb1957]

yes, triangular slices won't work. you should be able to draw a CL along a slice and measure the width of the slice at lots of positions.

another day in paradise, or is paradise one day closer ?

 

[berkshire]

Look up parallel line sheet metal development . Here is an example of what you are trying to do, this is for a dome , for your dish you do not need all of it but you can get the general principles. see the link below. If you need the full dish then the segments have to be hollowed by mechanical means.
B.E.

You are judged not by what you know, but by what you can do.

 

[chicopee]

I am assuming that you are a degreed ME so you should not be overwhelmed by a text on descriptive geometry which will show you how develop on a 2D plane these triangular flat shapes prior to bending them into elliptical shapes so as to assemble them to a dish configuration. The sides of each triangle on a 2D plane will not be straight lines.
I know that in the past, CE's matriculated in schools of engineering were required to take mechanical drafting including descriptive geometry, so if you know a CE ask him to help you.

 

[robyengIT]

Hope it can help

 

[drawoh]

Naylor,

I take it this is approximately parabolic, as opposed to exactly parabolic? Also, I take it you are trying to model this thing in CAD.

Read up on parabolae. You can model them from first principals, using whatever characteristics made you decide to do parabolae. Another approach is to model a solid parabola, cut faces off, hollow it out then convert it to sheet metal.

Before I realized SolidWorks did parabola, I modelled a curve that reflected collimated light rays all through one point.

--
JHG

 

[Compositepro]

There appear to be lots of resources on the Internet if you Google how to make a parabolic dish.

 

[Occupant]

It took a while, I thought I'd try it mathematically and plot it in Autocad. I have attached a PDF. However, I have not tested the output as to whether or not it is correct.

 

[pperlich]

SolidWorks Premium 2015 can make flat patterns from surface bodies.

 

[rb1957]

my IE10 doesn't want to open your attachment ?

another day in paradise, or is paradise one day closer ?