Well done! And if you don't mind - I'm going to copy it!
That said - you will likely have an issue with friction due to the metal on metal design of the idler bracket in contact with the rod. So grease will be needed.
Note also that the rod used could be replaced with tubes into which a hole could be drilled into which we could secure a screw-thus nullifying the need for trapped nuts. The tube would have to be sturdy tho so as not to flex.
That said - you will likely have an issue with friction due to the metal on metal design of the idler bracket in contact with the rod. So grease will be needed.
Note also that the rod used could be replaced with tubes into which a hole could be drilled into which we could secure a screw-thus nullifying the need for trapped nuts. The tube would have to be sturdy tho so as not to flex.