Jump to content

Ellipse size

Recommended Posts



I have more of a geometry question, rather than CAD question. I need to determine the size of a spar hole for an airplane wing. The wing will be cut out of foam with a hot wire. There is a round spar hole in the wing that runs from the root to the tip on each wing half. A carbon fiber rod goes through it. Seems easy, but the wing is swept back 35 degrees, so round hole will actually be an ellipse is when it exits the root and tip. The hole needs to be 5mm. The ellipse will be 5mm tall, but how do I figure out how wide?





Share this post

Link to post
Share on other sites

I would draw it out. Basically, it appears that you have two 5mm wide objects crossing at 35 degrees. So draw them. The ellipse will be 5mm high but will be as wide as the intersection of the two.


I drew the ellipse by clicking on the two intersections for the major axis, and then inputting on the keyboard 2.5mm as the minor axis. :D


Share this post

Link to post
Share on other sites

If you are doing this in 3D then I would simply place a rectangle at the desire angle.

The width of the rectangle should be 1/2 the drill size.

Then revolve the "drill" and subtract.

No calculations required.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now