Below is a calculation sheet for contractors looking to find out the offset needed when trying to fit a field gate to a post and get it to rise a certain amount as it opens to the 90 degree position.
If you want it to raise beyond that it will continue to rise and will work on there being a rotational angle option in the future.
You can fit the top and bottom hinges as normal and in line on the gate you are looking to hang.
The first measurement is from the end of the gate to the centre of the hole in the top hinge now attached to the gate.
Fit the top hinge as normal to the posts we usually do it in the centre or closer to the entrance gap depending on the rise and distance needed from the calculation so not to compromise the posts.
Work out the height you need the gate to rise with a rail and level or other method.
Then measure the distance between the top and bottom hinge, usually if not reversing hinges it will be from the bottom of the two hinges on the gate i.e. bottom of bottom hinge to bottom of top hinge.
You will now have the distance back from the vertical of the top hinge to get the rise you need.
We have tried it once and it worked but will be putting it to the test when we need it, in the meantime we have a hinge on a plate that we screw in to check and previously we used to work it out till we did the maths.
Happy fencing Pete