router techniques?

[Cliff Rohrabacher]

1.)<!--[endif]-->I have been contemplating a way to router out a concave ellipse – without a CNC router. I have seen some cool looking concave ellipses with nice sharp edges cut into the faces of panels. I have wondered if they are made on a RAS by loosening the tilt mechanism and running the blade through a series of side cuts ( scary thought that). However , I suspect they are router work though I can find nothing on producing this geometry. Any ideas? ?
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<!--[if !supportLists]-->2.)<!--[endif]--> Coopering real coopering. The staves of a barrel are shaped to product both the barrel shape when bent to shape as well as the watertight joint. The only coopering techniques I have seen are either hand made or entirely industrial using specialty machines. I’d like to try forming the staves with a router. The geometry is complex as the staves are angle edge jointed along a tapering curve. Any ideas??

[Keith Outten]

Cliff,

I saw a hanging jig one time that suspended a router above the workpiece. There was some kind of ball joint at the top of the hanging frame that allowed the router to swing and machine a concave surface. I'm sure it was in a woodworking magazine but I can't remember where or when.

[Cody Colston]

On one of David Marks' episodes he made a table with a bowl routered in the top. He made a jig that looked a bit like a skate board ramp with the middle open. :confused:

You might check out his DIY network site. I believe all his shows have how-to's there.

[Barry O'Mahony]

For an ellipse, the approached I'd take is to make an elliptical template, and use that to route the expensive wood with a flush trim bit. MicroFence makes a jig that will route elliptical shapes.

[Lee DeRaud]

On one of David Marks' episodes he made a table with a bowl routered in the top. He made a jig that looked a bit like a skate board ramp with the middle open. :confused: The Marks jig does a circular cavity, but I'm getting a headache trying to figure out how to adapt that setup to do an ellipse...my instincts are telling me "no way".

[Jeff Eiber]

I've attached a drawing of the concave ellipse which I think is the shape you're trying to make.

Many years ago I used a router copy/carver to create sailboat rudders using a tool similar to what is shown at the site wood-carver.com. This tool may be more complicated than is necessary to make the concave ellipse but should work if you can create an original pattern of the concave shape you want to reproduce.

[Cliff Rohrabacher]

That carver is so elegantly simple. I could make that thing with a few linear slides some drill rod and some 5/8" X 2" aluminum bar stock. Even the "brake" is simple. They want over 2-Grand for that. Wow.
I always wanted to make arch top guitars.

I'm thinking I can do the ellipse with a dual pivot swing arm suspending the router. The pivots would be 90Deg opposed. One would be adjustable along the Z axis.

I'm liking this idea more and more.

Check this out:
http://www.modernlinear.com/

The guy has linear motion components at very - very - very good prices. It's a brand new company. I found it while surfing for linear slides. I was on the phone with the owner (Steve) the other day he's a nice guy and more than willing to spend some time with you. The bearing wheels are class 5 bearings - meaning they are damn good.

[Jay Knoll]

It shouldn't be hard, I saw Marc Adams demonstrate a combination circle jig and and a elliptical jig to cut out exactly the same thing.

The elliptical jig is a piece of wood, about 10"square with two dove tailed tracks routed in one side, exactly square to each other. Then he hollows out the corners of the base so the router had room to move. (Looks like an inch each side of the routed track, turn a coffee can upside down to join the marks to get a curve.

Then he made two little wood pieces that fit in the dovetail tracks, put a pin in each piece.

He had a circle jig for the router with holes that would allow him to cut circles in diameters from 6" to 28" in 1/2" increments.

When everything was done, he stuck the jib onto a piece of wood with double stick tape. Put on pin in the circle jig at the 10" spot, the other in the 13" spot, turned on the router and did a great 10" x 13" ellipse in less time than it has taken me to type this out.

The plans are in his CD -- Advanced Router Jigs and Fixtures, since he sold them I assume they are copyrighted and I don't think it is fair to copy and put them on the web

Jay