It is crude but it works pretty good. It is just a steel block with a threaded rod through it and the blank goes on one end and the gear to copy on the other end. This gear had an 8 tooth section stripped out so when I got to it I stopped the mill with the cutter in the last finished tooth and indexed the bad gear to a good section and picked up again.
Actually it will hold up fine as far as durability and corrosion protection. It is just the finish that goes "chalky" with extended exposure to UV.
I have been using POR-15 for well over 10 years now and I am surprised at how well it holds up in even some of the most harsh environment. If you look I have not put the POR-15 anywhere on the top side of the trailer, only the underside (with the exception of where the wood planks will be). The top side is getting a couple coats of etching primer followed by single stage urethane automotive paint so it will withstand the UV.
Mike.
This one was a involute gear cutter I had lying arond and it just happen to be the right tooth profile.Mark I like your quick easy to use set up , it's probably as accurate as a lot of expensively attempted home made ones as well .
Are the milling cutters pre-ground to size or did you have to mill or grind them to fit the cog ? I'm asking for that tuye of fit /accuracy in cutting a few cogs is something I want to try on my old lathe .. I don't have a mill so am limited to ready made /sized cutters .