The problem I had with the celtic knot pens was holding the pen blank in the same position every time. To get around this, I built this rather simple jig from a bit of phenolic plywood. The jig was to hold the blank at 30° and cut the saw drift in the same position each time. Unfortunately, the fence being at 30° meant the cut was at 60°.
This is yew with mahogany infill
This produces a very tight knot, which although it looks good, is too bunched up for my liking.
I moved the fence to 60°, so the cut would be at 30°.
Unfortunately I forgot to adjust the blade height to compensate for the different blank thickness.
This one is maple with mahogany infill
This spreads the knot, but leaves the odd gap where the infill was obscured by the remaining timber. I think I also need to use a finer blade with finer infill.
The jig itself is a simple affair. A piece of plywood with hardwood “slides” to fit the guides on the table saw.
This then has a fence and a couple of clamps to hold the pen blank in place
The addition of a stop block keeps the pen blank in the same position each time. This was with the fence at 30° to the jig.
This photo shows the fence at 60° to the jig, which places the cut at 30° on the blank. And yes, the clamps have been moved to accommodate the new position.