Router Bit Search - Pear Shape??

[Glen Blanchard]

I am building a box and would like to countour the outside of it to be roughly the same as a Bombay chest. I am not certain how to best achieve the concave portion of the countour. My first impression is to secure a vertically oreinted router bit that has a "pear" shape. The other idea is to use a bit shape that is completely round (e.g. globe shaped) and then merely do some sanding to achieve the proper contour.

Is there such a thing as a "pear-shaped" router bit? Any other ideas on how to achive this contour?

[Jamie Buxton]

What I'd do is to make one long board with the correct profile, and afterwards cut it into the four box sides. I'd start by roughing out the concave part with the tablesaw, using that technique which makes crown molding. Then I'd form the convex part with a handplane. Finally I'd sand out the tablesaw marks and at the same time blend the concave section to the convex section. I've done stuff like this to form moldings, and it goes pretty quickly.

For my first attempt I'd pick staight-grained material which will plane nicely.

[Byron Trantham]

A variation on Jammie's suggestion is to use round nose bits or core box bits with a table mounted router. Draw the profile on the end of the long blank raise the bit a little at a time to cut away most of the material. These bits would leave a smoother surface making it easier to sand. I think it would be easier to control as well. Good luck.

[glenn bradley]

#7856 on this page maybe?

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_door.html#door_lip_bits_anchor

[Jim Becker]

I am thinking it may be best to use multiple cutters to generate your profile in a long piece of stock which you then cut down (and miter) to make your box. This may include coving on the TS if the profile is large enough and then cleaning up with planes and sanding blocks. Draw a cross-section of what you want and think about what you could do in multiple passes to get where you want to go. (This same technique is useful for many moldings and picture frame stock)

[Per Swenson]

Hi Glen,

And then there is the ye olde multiform router bit.
This is only a example. All of the big companies have a variation.

Per