This is the sort of gate I usually think about, although the same method applies to any sort of hinged mechanism.

That’s a picture of a Sketchup model made from a hinge by Matthew Miller and a gate by Adam J. Having fooled around with Sketchup for a couple of hours, I did wonder if it would have been easier to go outside and find a real gate. But, I got there in the end.

With the gate in its closed and latched position, everything is true and square. Here’s a picture of the hinged end of the gate, without its gatepost. The top hinge is directly above the bottom one, so this gate will open level, not rising.

The surfaces marked “horizontal” and “vertical” in the picture are, not surprisingly, vertical and horizontal. This is true for ordinary gates and for rising gates too.

Here is the gate modified to make it rising.

click the picture to enlarge

The gate hasn’t moved 1mm from the previous picture. Only the bottom hinge has moved. I added the white spacer screwed to the gate, and I drilled a different hole in the gatepost to match. The whole bottom hinge has moved out and left compared to the previous picture. But the gatepost is still vertical and the gate is still all vertical. Because of the slight offset of the hinges, they should be twisted a little so pins of the two hinges line up exactly straight (but tilted). However, this sort of gate hinge is usually made very loose, and the hinges work fine with the hinges out of line. If I’m being very pedantic, I twist everything to line up precisely. I find that easier to do with a power drill in my hand than I do with Sketchup 🙁

As a reminder from the previous blog post, what I’m trying to avoid with this design is this:

This picture shows how the gate skews as it opens and doesn’t sit vertical. I want the gate to be vertical both in the closed position and the open position.

Now, the real trick is to understand how much the bottom hinge has to move out and move left for any particular gate. That will be the subject of the next post.