In my previous post, I 3D printed parts to hold down the Load Sensors. In this post, I fix the counterbored holes to keep the nuts from protruding below the bottom of the bottom piece of plywood.

In the woodworking post, I used a router to cut counterbore holes on the bottom side of the bottom piece of plywood.  These holes hold the nuts that hold the circuit boards.

Unfortunately, the router bit wouldn’t cut the center of the hole, so it couldn’t cut deeper than about 1/8″ – about half of what I needed.  Oh, and I probably burned the router bit too – don’t force the router, kids.

So I decided to try a Forstner bit.  Forstner bits are designed for drilling counterbore holes; they make a nice, flat cylindrical hole. But I didn’t know whether I could use a Forstner bit in a router. It turned out well – the bit fit in the router and fits great in the plunge router.

I was able to set the plunge depth to the 1/4″ I need for the circuit board nuts, and in no time had cut all the holes to the correct depth. I think I set the speed low enough to keep from burning the bit.

In my next post I do some more 3D printing, both good and bad.