How can I router / cut a 8' long half ellipse

[Knottys]

Hello everyone,

looking for some suggestions here, I have a 10x5' counter that I want to router a 8 foot  half ellipse.
I basically need it to start 1 foot in from the ends.  the total  curve will be  8' long and 12" high. 

i thought of making a template out of plywood and strewing it on to my counter so i can router it that way but then again how would i make the perfect template.  I have a circle cutting jig but that would be a 20' diameter circle.

Im stuck , what would you do?

Thank you
G. knottys

sorry for the duplicate post, this is the right page for it ,  ill try to figure out how to remove it from general.

 

[Brent Taylor]

Hello, I'm new to the FOG, For my background, I have been a Builder/Woodworker for over 40 years. I have used both templates and trammels to do large radii, ie: circle top windows, barreled ceilings and counter tops. I have used plywood strips to make the trammel and if I were to cut the top using the the trammel, I would used 3-M's Red Line auto trim tape to fix a block to the counter top and a spacer of the same thickness at the router end of the trammel. Peter Parfitt's bench making videos, I think would be a great help to you in your projectI, his way of using the template with the guides is amazing ( I felt like an a$$ for not using it sooner. Old dog, new trick. always learning. Thank you Peter, again.) Use the same method to layout and cut your template, if you are using that way of cutting the top. Brent 

 

[stvrowe]

Are you wanting an ellipse or a circular segment?

 

[Holzhacker]

Whenever I used to have to cut things like this I always wanted to be able to see and adjust angles or curves. A little this way or that can make a huge difference in a good looking curve or a great curve.
Go to your local lumber yard, drywall, metal stud supply house. They should have an articulating track that's used for building curved walls with metal studs. Works great.
The track is stable but very slinky to shift this way or that for marking, can be clamped or screwed down for cutting along, and can be used over and over again. Once the track is set I clamp a masonite strip along the face so that the router or jigsaw had a nice smooth surface to run along.
Hope that helps

 

[semenza]

    If you have an 8' pipe or bar clamp cut a strip a few inches wide of 1/4" plywood or something similar (of course you will need more than eight feet) put it in the clamp and tighten to make it bow. You can adjust the amount of curve very easily this way and see what you will get. Then that can be used to draw a line or mark another piece for a template.

    You could also do this with a couple separate clamps or something to push / bow the piece between.

Seth

 

[GhostFist]

TIC did a fairly robust article on ellipses and cutting them. Read this...ellipse

 

[Gr8trim4u]

This is a link to a post I had a really long time ago under my old user name. It will cut about the size of you need. If you have any further questions drop me a link.

http://festoolownersgroup.com/member-projects/really-big-elipse/

Anthony