In my previous post, I 3D printed parts to hold down the Load Sensors. In this post, I correct the counterbored holes that 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.
![bad counterbore holes that don’t hold the nuts](https://bluepapertech.com/wp-content/uploads/2023/04/20160502_203322Bwiki-768x576-1.jpg)
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.
![A Forstner bit in the router](https://bluepapertech.com/wp-content/uploads/2023/04/20160504_202158Bwiki-768x1024.jpg)
![The bit fits fine in the plunge router stand](https://bluepapertech.com/wp-content/uploads/2023/04/20160504_201236Bwiki-768x576-1.jpg)
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.
![Setting the bit depth to 1/4″](https://bluepapertech.com/wp-content/uploads/2023/04/20160504_201533Bwiki-768x576-1.jpg)
In my next post I do some more 3D printing, both good and bad.