Stop my tree swing from twisting!

January 19, 2008 5:13 PM

How do you stop a tree swing from twisting?

The branch it's attached to is higher on one side so the swing wants to twist. The swing itself it just a piece of wood with four eye hooks in it. How do I counteract the twist? Will some kind of stabilizer bar work? What is the best way to tie the rope (knot suggestions etc)

Thanks!

posted by zeoslap to home & garden (10 comments total)

If one end is longer than the other, it will always twist, no matter what you do. It has to. You have to find a way of equalising the length of the lines the swing actually pivots on.

One way of doing this is to replace the part of the longer rope of the swing that is higher than the shorter with a rigid link. ie finding a way of mounting two (identical) lengths of rope onto a sloping branch. Perhaps a long hook bolted into the branch at the higher side? Or if you made something rigid that forced the longer end of the swing rope to pivot at the same height as the other (A solidly mounted metal tube over the rope), it would be less inclined to pivot. Moving them apart would also help (once they are equal).

What's the difference in height? Do you have a picture? It'd be easier to give suggestions with some idea of the scales involved.
posted by Brockles at 5:22 PM on January 19

What about inserting a spreader bar near the top of the swing? Perhaps this would mitigate the differential in the lengths of the rope.
posted by nkknkk at 5:28 PM on January 19

The branch is about 15'-18' off the ground and the swing is about 20" wide rope to rope. I'd estimate the difference as being between 6" & 9" it's getting dark now but can take a picture tomorrow.
posted by zeoslap at 5:55 PM on January 19

You'll also want to make sure the ropes from which the swing seat hangs are not parallel to each other--that is, the width where the ropes connect at the seat should be 3/4 of the width where the ropes connect at the branch. If you're facing the swing, the ropes and seat should form a tall, skinny, inverted isosceles trapezoid.
posted by fandango_matt at 6:05 PM on January 19

I read this as more of a zen kōan. Tree swings twist, it's part of their nature, and part of the enjoyment.

If you eliminated one of the ropes, and went to a tire swing, or a single plank 'rope through a center hole', you'd avoid the problem as well.
posted by pupdog at 6:06 PM on January 19

Ah, I just saw the swing is 20" wide, rope-to-rope. Make sure the rope-to-rope distance up at the branch is at least 60" (5').
posted by fandango_matt at 6:09 PM on January 19

Put in a spreader bar about halfway down the length.
posted by sanka at 6:15 PM on January 19

the width where the ropes connect at the seat should be 3/4 of the width where the ropes connect at the branch.

Ah, I just saw the swing is 20" wide, rope-to-rope. Make sure the rope-to-rope distance up at the branch is at least 60" (5').

Are you changing your story, or is your maths deeply suspect?

5 foot is a bit excessive, I think. I'd have said between 30-40" is more than enough.
posted by Brockles at 6:19 PM on January 19

Yeah, I changed my math when I saw the swing was 15' to 18' off the ground.
posted by fandango_matt at 6:27 PM on January 19

So I really spread the ropes and lo and behold, minimal twist!
posted by zeoslap at 9:54 PM on January 20