A few years ago I saw a artical in a wood working magazine about a depth gauge for setting saw blade to a specific hight. Looked simple enough. So for me that was a good thing. A scrap piece of 3/4" plywood, a 6" steel rule Pice of clear plastic and a rare earth magnet to hold the steel rule. A scribe mark in the plastic with a little red ink rubed into the scribe mark to make it show up well. Easy enough..... I already had every thing but the steel rule..$9.00
Rare earth magnet.... $8.00 for 10 of them. So $17.00 and about 1 hour of fun making it. It works great. Some times I just set a brass set up block on the table and bring the steel rule to make contact and it is perfect even with out reading the scale on the rule...in 64ths. Some times hard for these old Eyes to see with out glasses.
Now Rockler sells one ready made for $9.99 Oh well It most alway happens that way. But I had way more fun with mine then those who bought one.