With the soapbox car complete it was time to get back onto the gate project. It’s already September and I have come to the realization that I have failed at my summer to do list. The fireplace got a start but is not going to see completion this year. The gate does not have much left to complete and I need to get it finished off.
The main frame and hinge assembly have been fabricated and it was time to get some work done on the latch mechanism. This is the point in the project where I struggled a bit. I came up with this really cool idea for a latch. My plan was (yes that was past tense) to built a mechanism driven by a series of chains and sprockets. The idea was to make the outside of the gate look pretty while the backside was going to be a display of mechanics. I had collected and cut apart a few MTB rear cassettes and chainrings. I then bought aluminum turning stock to build hubs for all the sprockets. I had built an arbour, for the lathe, to turn the hubs and then made three test hubs to perfect the design. I had even considered building in a pneumatic actuator to make the latch mechanism operate at the push of a button. My air compressor sits about 12” away from the gate on the inside of my garage. How awesome would it be to have an air powered gate. After I had everything lined up, figured out, and in place the wife caught a glimpse of the design. It turns out that my idea of cool and her idea of cool are two different things, weird huh?
So the plan for the latch is this, a couple of handles that control a sliding latch pin. It’s kind of boring and not all that creative but I have a relationship to uphold. I was going to attempt to put some personal touches into it and hopefully come up with something that was slightly unique with the look of not being store bought.
I really wasn’t sure how I was going to build this; I had given it no thought and had to change the plan on the spot. I wanted some beefy looking handles so I drew out a handle design on a section of .500” steel plate and went to town with the plasma cutter. With 2 handles cut I spent time cleaning up the edges and rounding out the corners. The handles turned out fairly heavy which is what I wanted; they will hopefully give the latch a good smooth feel.
It was time to come up with the internal mechanism. I struggled. I think I have about 12 hours into the fabrication of the mechanism. I realize that when you see the pictures it is hard to justify 12 hours however this is what happens when I don’t know what I am doing. I decided to conceal the latch within the thickness of the gate. To complicate it all I only had the thickness of a rough sawn fence board to work with which is 1 inch thick.
I am not going to give a play by play of the latch build, if you look at the pictures you can probably figure out what I did. The highlights though are as follows; I used a 5/8” keyed axle section that was left over from the soap box car as the main pivot shaft. Everything was built to be keyed to the axle. The spring mechanism was built using a spring from a tilting and telescopic steering column out of a car. The spring had to be cut in half and modified however in the end the spring tension turned out fantastic. It was the right tension to be able to handle the heavy handles and the latch mechanism. The pivot shaft got mounted on a couple of wheel bearings that were punched out of the rear wheels of the soapbox car. The bearings allow for super smooth operation. The latch pin was built from .500” cold rolled steel round bar. I needed something heavy enough that would not bend when the gate gets slammed shut on it. After sorting through the mechanics of it all, making a few mistakes, and redoing a few things the latch came out great. The feel, movement, and tension are all perfect.
It was time to get things prepped for a test fit. I TIG welded on all the hinges that I had previously fabricated. I had fairly tight tolerances in all the bearings and I feared the hinge brackets would warp slightly once I put the heat to them. They actually all turned out great except for one. The bracket warped about .080” so I ended up shaving down one of the aluminum spacers to make things right.
With the hinge on and the latch built it was time to mock things up on the fence post. I squared things up and temporarily mounted the gate into the hole it would eventually fill. The fit was good. I had a slight gap on the latch side however I was happy with it. I live in an area where summer can get hot and winter can get very cold. The frost heaving often causes fence posts to shift slightly. With the gap that was built in it will allow for a bit of movement and hopefully gate alignment will not be too much of an issue season to season.
The gate hinge design worked out great. The swing is smooth and the input effort is low. I would not say the gate is excessively heavy but it does have some weight to it, the hinges handle the load no problem. With the gate temporarily mounted I was able to build the striker plate. I built the plate out of a 3” section of 2.5” angle iron. The 6×6 rough lumber fence post that was going to support the striker plate was routered out to allow the plate to inset and sit flush. I built the striker plate this way in case I ever need to modify it. Like I said previously, fence posts move with the frost and this causing the gate latch pins to not always line up with the striker plate season to season. If I need to make adjustments I can easily do so.
So I am at a point where all the fabricating has been done and it is onto to paint prep stage. I think unit will get a few coats of trusty oil based Tremclad, I am considering going flat black however I am not completely sure yet.