The Naiad Voyages

Mark Austen

2016.09.22 - Cutting Large Circular Holes

We are getting close to the stage where the cabin sides go in but before they do six holes need to be cut in each side, three for the open-fronted stowage and three for the port lights. The stowage holes require a jig, already made, and these holes in the cabin sides will be roughly cut with a jigsaw and then trimmed to match the jig with a follower bit in a router. But the circular holes require something a little different. There are a number of instructional videos on the Internet for doing this and I decided to make a router jig just for the holes I needed to cut.

And here it is. A bit rough and ready but after the 6 holes are cut I'll not be needing it again.

The router is screwed on like so...

..the pivot screw is mounted in the work piece, just a piece of scrap for the test...

...the pivot hole set to 80mm from the outer edge of the router bit...

...the jig is placed on the pivot, the router turned on and the whole thing carefully swung around the pivot. You need to make sure that you do this on a piece of scrap timber otherwise the router bit carves a circular pattern i the workbench.

And voila, one circular hole.

The parallax makes it difficult to see the width of the hole but it is 160mm as expected.

This hole size is for the non-opening port lights shown here although I'm not going to remove the protective plastic film until I mount the thing for real. Not bad.