Malcolm Wheeler
12-01-2011, 1:29 AM
I have concluded that the following is impossible to achieve, but before I admit that, I figured I should ask here for some advice.
I am building a marble machine, and I need advice on how to route a narrow small radius inside (concave) surface, using a plunge ball bit. The objective is to make open topped, partially enclosed tunnels in the narrow curved edge (one inch wide) of a block of wood. (see router bit picture below to see what I mean).
I have attached two pictures of the kind of radius I am talking about to try and illustrate the concept. *HOWEVER* the pictures are misleading in that they have an open topped channel (easy to route with an internal bull nose bit) but my goal is the partially enclosed tunnel.
214315214316
The radius I need is about 4 inches, but please note I do not have a small trim router – my router motor is 4 inches in diameter. I thought initially that I could build two templates either side of the block of wood for the router motor to ride on ( with the base plate removed ) but I don’t think the router bit will extend out far enough. I have seen bit extensions for sale, but don’t they vibrate like crazy?
As I said – I think it is impossible to achieve (unless bit extensions really really work) – I think I will have to route two surfaces with an internal bull nose, glue them, then partially cut one side off on the band saw.
Here is a picture of the bit I want to use from the Lee Valley website.
http://www.leevalley.com/en/images/item/woodworking/router/19j1906bh.jpg
Here is a picture of the bit I think I will be forced to use at the end of the day and glue...
http://www.leevalley.com/en/images/item/woodworking/router/16j5006bh.jpg
Thanks for any advice!
regards
Malcolm
I am building a marble machine, and I need advice on how to route a narrow small radius inside (concave) surface, using a plunge ball bit. The objective is to make open topped, partially enclosed tunnels in the narrow curved edge (one inch wide) of a block of wood. (see router bit picture below to see what I mean).
I have attached two pictures of the kind of radius I am talking about to try and illustrate the concept. *HOWEVER* the pictures are misleading in that they have an open topped channel (easy to route with an internal bull nose bit) but my goal is the partially enclosed tunnel.
214315214316
The radius I need is about 4 inches, but please note I do not have a small trim router – my router motor is 4 inches in diameter. I thought initially that I could build two templates either side of the block of wood for the router motor to ride on ( with the base plate removed ) but I don’t think the router bit will extend out far enough. I have seen bit extensions for sale, but don’t they vibrate like crazy?
As I said – I think it is impossible to achieve (unless bit extensions really really work) – I think I will have to route two surfaces with an internal bull nose, glue them, then partially cut one side off on the band saw.
Here is a picture of the bit I want to use from the Lee Valley website.
http://www.leevalley.com/en/images/item/woodworking/router/19j1906bh.jpg
Here is a picture of the bit I think I will be forced to use at the end of the day and glue...
http://www.leevalley.com/en/images/item/woodworking/router/16j5006bh.jpg
Thanks for any advice!
regards
Malcolm