So I got a bit carried away with the gate hinges or perhaps it was a simple case of just “going with the flow”. Going out and purchasing prefabricated hinges just didn’t sit right with me; I had put good effort into the main frame of the gate and I wanted to carry the custom fabrication throughout the whole design. I wanted to come up with a unique design that revolved around functionality (pun intended). The criteria? The swing needed to be smooth and once that was achieved then it needed to look unique.
Obviously there is only one way to go when dealing with smooth and that way involves bearings. The swinging gate will inflict both axial and radial loads therefore I decided to go with a cheap, yet effective, tapered roller bearing set up. I got my hands on 2 sets of L-44610/L-44643 one inch trailer axle bearings. The idea was to machine up bearing guides that would allow me to adjust out both endplay and preload. I new the size of the hinge was going to get beefy but I think the look was going to work in the end.
I began by designing the function portion of the hinge first. Using 2” round 6061 aluminum stock I spun up 4 guides that would fit inside the 1” bore of the bearing. The guides had center holes drilled out to .500” to accept a threaded hinge pin. The bearing races needed a spacer placed below them to allow for some clearance so I enlarged the inside diameter of some 2 inch washers to allow them to fit perfectly under all the races.
With the bearing assemblies supported it was on to the brackets that would allow the bearings to do their job. The brackets, that would eventually get welded to the hinge plate and gate frame, were all cut from 2.5” x .250” flat bar. For the set up to work I really only needed 2 brackets on the hinge plate, an upper one and a lower one; but I decided to cut 2 more extra to not only maintain a clean, symmetrical look but also provide some weather shielding for the bearings. The brackets were all sliced out with the plasma and then cleaned up on the belt sander.
I was able to mock up the hinge assembly using a short length of .500” threaded rod. By double nutting all the bearing adjustments I was able to set the bearings so they had no endplay and no preload. Although the hinge brackets hadn’t been welded yet to the frame or hinge plate I was still able to confirm the smooth movement. It looks like functional design of the hinge is going to work, well at least work in the horizontal position with no load on it.
It was time to move on and pretty things up. I did not want to leave the bearings exposed to the weather nor did I think the visual side of things looked that great. I made a trip down to the local metal supplier and picked up some small sections of 6061 aluminum rod stock. I was able to machine up some covers for everything. The bearings are now hidden by some 2.5” aluminum tube sections that just float in between the hinge brackets. The upper and lower nuts on the hinge pin are now aluminum capped. And the hinge pin which is a 5 foot section of .500” threaded rod is hidden by a section of .500” copper tube and finished off on the ends with some tapered aluminum caps. The caps were all cross drilled and tapped to accept set screws for locking down. The copper tube will eventually get painted black to match.
I held off welding the hinge brackets on until the rest of the gate fabrication is complete. I wanted to be able to place the gate flat in order to work on the latch system. So for now the hinge gets set aside and it’s onto designing and building a latch. I have some ideas floating around my head but haven’t settles on anything yet. I do know that I would like to achieve a unique design. I’ll see what interesting concpets will trigger the imagination over the next few days.