The physics of swinging in a hammock and how to make it frictionless

[vanRijn]

I sleep in my indoor hammock every night, and as I go to sleep, I love to swing side to side gently. But when I swing myself to sleep at night, right now I'm only able to get about 15 good swings from one push. I would like to figure out a way to get more gentle swings and swing longer before I have to push off from the wall again.

I bought 2 Black Diamond Rotors from Amazon (http://www.amazon.com/gp/product/B0013G4V4G), thinking that they would solve the problem for me and help me swing longer. But I just tried them tonight and they didn't help the problem at all.

On each end of my gathered end hammock, I have a dogbone wrapped 3 times around the gathered end, then have that connected to a Dutch Buckle on poly webbing, which attaches to a climbing biner, attached to a soft shackle, which finally attaches to a surface mount tie down (http://www.amazon.com/gp/product/B000HAEPAO), screwed into wall studs with 2 #14x3" SPAX screws.

I tried putting the Diamond Black Rotors in between the dogbones and Dutch Buckles and that didn't help. I also put them between the poly webbing and the soft shackles and that didn't help either. It doesn't look like either of these points in my suspension are twisting or impeding the swinging motion.

I've seen some hammock stands that offer frictionless mount points for the hammock to facilitate swinging, but I don't know how I can do the same thing with my indoor hammock, mounted to my walls. Would pulleys be a better solution than the rotors? And where should I put them, if so?

Has anyone tackled this problem before and come up with a solution? Just looking at the physics of the suspension and the swinging motion, I don't understand what forces are at work at what points in the system are causing the swinging to be impeded.

I'd really love any and all help you guys could lend me. Thanks very much in advance!!

[Gsx-rboy750]

Gravity not friction is your problem. When you figure it out let me know and i make you rich. But seriously maybe some type of baby crib mechanism might be able to be integrated. Unfortunately it takes energy to release energy.

[XTrekker]

You are loosing momentum to many things like the stretch of the hammock and suspension as it swings, the air itself, and the friction of the connection points. Adding sag to the hammock may increase your swing time considerably. You could also replace as many stretchable materials as possible for materials that stretch very little. I am just a student in college but just finished physics and a mechanical statics and dynamics class. There may be some more knowledgeable physics majors here that can help out.

[f k]

Watch the rotors when you swing. I would bet that they are simply working as an extension in your suspension, with no twisting in the rotor it self. To benefit from any reduction in friction that the bearings in the rotors offer you will need one end to be as close to the wall as possible and have something limiting the movement of that end. Otherwise there is just not any torque on the axis of the bearing.

There may be some other ways to do what you want, but I will have to think about them longer before I suggest any.

[Mumbles]

You need a elf. S/he can tug your side tie outs or gently push from one side.

[gophin]

vanRihn, i too sleep in my hammock indoors. mine has amsteel whoopie slings with the fixed loop run through the gathered end channel. one end is attached to a screw in eye bolt & the other end has a climbing carabiner between the eye bolt and the whoopie sling.

as soon as i read your question i had to know...so i got into my hammock and pushed off. obviously the swings get progressively smaller, but I was nearing 100 nice feeling swings when i got really comfortable and stopped counting.

i also have a fixed ridgeline (amsteel), which i think is key to the swing somehow. something about how the weight is distributed, maybe. probably supports xtrekker's statement about materials that don't stretch.

i also think the number of swings correlates somehow to the question of how many licks it takes to get to the center of a tootsie roll tootsie pop.

buona fortuna!

[The_hanging_dog]

my indoor setup uses amsteel whoopie slings attached onto the open version of Gophin's eye bolts, just a screw in hook really, very little friction and it feels like the swing lasts for hours!

[Dead Man]

I'm intrigued by your question. I have a hammock in my warehouse that uses whoppie slings and an adjustable ridgeline. It a long hammock as well. It's strung between warehouse racks. When I get in and push off I swing for up to 10 minutes. The distance of the side to side arc diminishes as would be expected but the time length gets me swinging enough that I just quit counting from being so relaxed.

I to believe it has something to do with the length of the ridgeline. Not much science. Just personal experience.

[oldgringo]

Ceramic bearings like they use on high end skateboards...

[CeeVee]

What about polishing the swivels? Clamp one end to a bench or something solid pack the swivel with Bon Ami or polishing rouge (from a moto-grinder) use WD40 spray as a lubricant and lo-speed twist the swivel for 3-4 minutes. Use care! We don't need defective hangers!