2021.05.19 - How to Cut 144 Notches Accurately

The mould and frames for the coble form the shape of the boat at intervals along the length of the hull. Pieces of wood, known as ribands, define the shape of the boat longitudinally and are set into notches in the frames and moulds.

Here you can easily see the two forming the entire shape the hull.

As you can imagine, the more accurate the frames, mould and ribands, the better the boat will be.

The task I am currently contemplating is how to cut the notches into which the ribands are set. They need to be accurate, precisely placed and easy to cut.

Here is a photo of the notches in the 8 frames and there are 9 notches per side. 

If this were just one or two notches, then I'd drill holes in the corners and a jigsaw to  cut out the waste. But not for 144!

My best guess so far is to create a jig and use a 6mm (1/4") straight router bit. The jig would be clamped in place and the router use to cut out the waste. Whilst cutting out the waste is quick and easy with this method it does leave rounded corners and I have the choice to either use a fretsaw or chisel to square off each corner or run each riband over a 6mm round over bit one the router table so that the two rounded corners on the riband fit into the rounded corners of the notch. This last one seems to be a lot easier and quicker to me.

The difficulty with the jig and router method is finding a way to accurately locate the jig on the workpiece.

I'm thinking about that.

Decisions, decisions !