This article was updated May 25, 2023. It was originally published Nov. 17, 2009. To put hard, durable threaded holes in plastics, engineers often specify threaded metal inserts that will securely ...

Making a homemade router sled flattening mill. This sled is designed with an inside dimension of 24in by 36in within the rails. **Materials List:** - (3) Steel Tubes - (2) Steel Channels - (4) Mending ...