wait are you routing the hole with a bit that is less than 20mm? I am not familiar with this. I use the dominofix, which uses a copy ring and plunge of a 20mm bit.
Yes, the Woodpeckers jig uses a 1/2" diameter spiral upcut router bit to make either 20mm or 3/4" holes. After the initial plunge, you then have to move the router in a circular motion around the jig hole 3-4 times to remove the extra material. For 20mm holes that would be 3.6mm or .143" per side.
I agree with you about the Festool 20mm hinge boring bit. I was pleasantly surprised.
![Smile [smile]](https://www.festoolownersgroup.com/Smileys/default/smile.gif)
I assumed I'd get some amount of hole burning because of spinning what is essentially a modified Forstner bit at 10,000 RPM. However, there was
NO burning what so ever. Who ever designed that bit got the tool geometries right.
Just a side note, for the first 30 holes I used a brand new Whiteside spiral upcut bit. For the remaining 30 holes, I used the Festool 20mm bit. The 2nd set of holes were rounder, were more consistent in size, required 75%
LESS effort on my part and took 50%
LESS time to produce.