You are extremely brave to take this on!!! Sarah.
Not difficult to do
Here are a couple pics of others.
Here is another. http://www.gittas.com/FreeStuff/I...
Try this link, have fun and hope you show it in projects
I liked the pdf link from zedna,Thanks.
It does look like hard work though.
you just have to do it when nobody is around to distract you
I can't help you with designs but here are instructions for a 15 sided biscornu.
Guess I didn't scroll down far enough as I have given the same info as you.
I know how to do it, but would like a embroidery design for machine
I would look thru the quilt block patterns. Please let us see a pic of it when you finish it. I have never seen a 15 side biscornu. I like the 8 side ones.
If I get a embroidery design by machine, I will post the photo of the finish biscornu