Jigsaw circle cutting jig

Does anyone have any idea how to make a circle cutting jig for a jigsaw that can cut up to a diameter of 1.2m?

Don't use a jigsaw, use a router.

Take a strip of ply the width of the base of the router by a bit longer than the radius you want to cut. Make a hole at one end that exactly fits the collar of the router. Then at the other end, use a screw/nail etc for the arm to pivot round at the centre of the circle.

you can apply the same as above but use a jigsaw, if thats all you have

You tube

like so, but quite a lot bigger


Thats the basic idea, as pointed out a router will make a better job of it.

You dont have to make a cutout for the whole base necessarily. Look on your jigsaw base for anything you can bolt to without intefering with the operation.