The Niagara came with a double U Joint. Unfortunately the joint is all plastic and will break under load. Before I discovered the all metal U joints I found one at Stock Drive Parts that worked and had a metal spider. Then saw the metal ones on eBay. You can use two metal ones to create one like the one Lionel used but about 1mm (.040") has to be removed from each end. Thats about the limit before damaging the set screw hole. I use a lathe but you can chuck it up drill motor and hold it against a grinder to get a fairly concentric finish.
Lionel in the center, SDP on the left.
Pete
