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I have a punching bag that normally hangs vertically, but I want to lift it up out of the way when not in use. The bottom of the bag has a strap that I can attach a rope to, and I have set an eye-hook off to the side so I can lift the bottom up to be level with the top so the bag is horizontal and overhead.

The bag is pretty heavy so I need some type way to easily pull on the rope to lift it and not have it fall back, yet also be able to easily lower it when needed. Because it's quite a bit over my head and is about 200 lb (90 kg), it's pretty difficult to try and push it up while also trying to rig something with a knot(it might be easier with a ladder but I don't want to have to haul one in every time I want to lower it or not nor do I want a pulley system with a bunch of extra stuff). Clearly it should not slip since I might be walking under it some times. (just in case).

2 Answers 2

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Considering that you

  • seem to be using an eye to pass the rope through

  • don't want to use a pulley system

  • are managing the weight but not tying a knot

then I suggest using a cleat such as this

enter image description here

fixed to a wall. It's important that the direction of pull of the rope is parallel with the wall, for strength, otherwise it is too easy to rip the cleat's fixing screws back out of the wall.

It's much easier to throw a loop of rope over a cleat than to tie a knot against the dead weight of the bag. Once the cleat, and the friction in the rope, takes some of the weight, you can adjust the tension/slack and tie it off.

If the bag is still secured at the other end, you are only lifting half its weight.

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It's not what you want to hear, but there is no easy way to do this without some sort of load reducing system; i.e. a pulley system. If you don't have a pulley system, the force you need to apply is at least equal to that of the weight (mass x gravity) of the bag and will always be difficult to manage.

@TobySpeight mentions in a comment that the force required will be greater than the weight at some points in the process.

A pulley system doesn't have to be hanging wheels with the rope passing through them, it can be as simple as some looped/knotted cords (load bearing so they need to be strong), with your tie-off rope running through them. Of course, the problem here is friction - it will take more effort to use such a system than it would with wheeled pulleys, but it should have the same effect. If you want to go down this system, I suggest you look for, or make, some ropes with eyelets, which will reduce the friction immensely. This can be done with an eye splice knot and an eyelet/thimble for best results, but any knot with a loop should work

eye-splice

(from Wikimedia commons, attribution to Alan W. Grogono)

An thimble looks like this:

thimble

(Image by Bernard S. Jansen from wikimedia, CC by SA 2.5)

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    Actually, if you're pulling the bag up and sideways, the force becomes greater than the weight of the bag once the angle between the two anchors from the centre of mass reaches 120°. (Note: it's wrong to compare a force to a mass - they have different dimensions) May 19 at 16:00
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    @TobySpeight re mass: true, in this case it should have been weight, it has been a while since I last learned physics...
    – bob1
    May 19 at 21:10

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