To make the rounded sides to the holes for the Gin glasses, I needed accurate holes larger than any forstner bit I have access to. To do this I used a large forstner bit to drill a reference hole. With the 2 sheets of MDF securely taped together, I then set a rabbet bit in the router table to just slightly above the bottom sheet (9mm in this case). The bit was set to cut a 7.9mm rebate, thus increasing the overall diameter of the initial hole by 15.8mm. I did this twice which left me 2 templates each with a set of different size large accurate holes.
Caution and safety: please note, not pictured here is the two grabber blocks I used to hold the templates whilst cutting the rabbet. It’s a fairly large bit and could easily do a lot of damage should it slip or grab the work-piece. The cut also needs to go against the spin of the bit; which, on a router table, can seem a little counter-intuitive; particularly when cutting holes. I also pre-cut the larger hole (with a jigsaw) to around 2 to 3mm shy of the final size as 7.9mm is a large cut to make in one pass! Also, even with under-table extraction, this was very dusty; wear a dust mask, especially when using MDF. Best advice: if you are new to router tables (or routers) be very careful attempting this.
