Step 8: About paracord

This isn't really a step; more like a justification of my methods. I've read a lot of forums where people say that paracord should NOT be used in this fashion. While I understand the concern, I also know that I've been using paracord on my hammocks for 2+ years now and I've never had a cord break on me yet. It's an acceptable risk to me, as falling may result in a bruise and nothing more.

*Edit -- If you look at the comments, I had an engineer explain the actual physics behind line tension (thanks, dchall8!), so this section isn't exactly right.  I still stand by my design because I know it works for me, but my math doesn't quite add up (I majored in Humanities in college).*

Let's do a little math about paracord. I'm an English teacher, not an engineer, so my calculations may be flawed, but here are my methods. The breaking strength of 550 cord is 550 lbs. The common wisdom is that the safe working load is 1/3 to 1/5 of the break strength, which brings the more conservative estimate to 110 lbs safe working load.

Then we need to factor in the knots. Knots can weaken a rope by 50% (although the figure 8 and double fisherman both are generally considered stronger than this), so let's put the 110 lbs down to 55 lbs. But then, there are 4 strands, so we multiply the 55 lbs by 4 to get 220 lbs. So according to my calculations, my hammock should be able to hold a static 220 lbs without fear of breaking. If you weigh more than this, expect to do a lot of jumping while inside, or plan on putting 2 people in your hammock, you may want to use stronger climbing rope. But this system works fine for me.

<p>so I actually made this but couldn't take pics. it works wonderfully!</p>
Paco why did u stop YouTube videos I live them
What material is best because I used a sheet and it tore and used a tarp and it almost tore so I jumped out.
Weaving three smaller rated cords together would give a stronger &quot;cord&quot;, but with a slight increase in cost.
For a lightweight hammock for backpacking order a very cheap nylon tablecloth form Tableclothsfactory.com. The edges are finished and they come in various sizes and bright colors <br>
hahaha, that video is pretty funny lol <br>
I love the ninja flip. For sure going to make this. Thanks
hey man GREAT ible great idea and great video. (taught me some knots aswell )<br>one question though. how small does it fold/roll up into ? (just roughly because i know material thickness etc will be a factor)<br>depending on that will be whether i make it. definatley a great thing for a camping bed and easy to untie for a makeshift shelter aswell !
Love this! <br><br>And I think I have all the materials already! =)
To avoid marking or damaging the bark of the tree you should use tree hugger slings. A separate about 40mm wide sling to wrap around the tree and then tie your cords into these slings.
Great idea! I have been wanting a hammock for camping, but I don't want to spend the $50+ for it. The information was simple and very easy to understand. I will be making this very soon.
Hey paco, really great 'ible. I decided to double the paracord and use climbing carabiners to make myself feel even more comfortable. Also, instead of using a bed sheet, I used black ripstop nylon. This unfortunately called for a small amount of sewing to clean up the edges, but no more than what a 17 yr old guy could handle. I did use a slightly different knot to tie the ends of the hammock up, as it looked a bit tidier (forget what it was called). Thanks for the great idea again!!<br><br>p.s. here is a picture of my hammock. I was too lazy to find trees in the woods and deal with bugs, so I simply hung it on our swing set for now.
I&nbsp;am an engineer so I can help you a little with your tension calculation.&nbsp; Assuming the weight of the rope and hammock are negligible compared to your weight, then you have to divide your weight by the cosine of the angle of the ropes make with vertical.&nbsp; The tighter the hammock is between the trees, the more tension will be on the rope.&nbsp; At 170 pounds you would have 85 pounds each on the ropes if you hung vertically from the branch.&nbsp; 85/1.00 (the cosine of 0 degrees) = 85 pounds.&nbsp; When you stretch them out to 45 degrees you have 85/0.707 = 120 pounds.&nbsp; If you stretched it to 60 degrees (more comfortable to me), you have 85/0.50 = 170.&nbsp; If you could tighten it to 85 degrees, the tension in each rope goes way up to 975 pounds.&nbsp; Your little aluminum &quot;keychain&quot; carabiners would be wide openb at that point.&nbsp; <br />
So this is why slackropes have to be extremely strong.&nbsp; They are trying to get the rope as close to horizontal as possible, thus increasing the tension exponentially.<br /> <br /> Thank you!&nbsp; I've been trying to understand this aspect of hammock physics for years, and you finally explained it in a method I can understand!&nbsp; So my design is already pushing the safe working limits of the carabiners.&nbsp; Oh well -- I haven't had one fail in 3 years of using them, so I'm not worried yet.<br />
&nbsp;The safe working load is VERY different from the breaking load. I would guess that each of those carabiners could easily hold 300+ lbs.
Yeah, you're probably right. There's a reason that they call it the &quot;safe&quot; working load, but then again, we're talking a hammock, not rock climbing equipment.&nbsp; The very worst case scenario for catastrophic failure of one of the components is a broken arm.<br />
Or hitting your head and dieing.
Unlikely from hammock height.
Some people hang hammocks high in the trees, some hang them across rocky areas where tent/ground camping is impossible. I've even seen one hung across a creek. For these applications you would want rock climbing rope and hardware. For the average backyard hammock, you can get away with a lot lower quality materials.
a hammock isnt my idea of <a href="http://www.hotelsandaccommodation.com.au/">accommodation</a> great way to relax tho.
I had a friend put 600 pounds on one of those aluminum carabiners once! It was bent at that point, sure, but it never broke!
Heh. Thanks for testing that for me! I knew those carabiners could hold! Once again, not recommended for rock climbing, but they're fine for hammocking.
Cool Instructable. Seeing as I weigh 220 I'll probably spring for some stronger carabiners and maybe double the amount of paracord.
Great 'ible! Very practical and easy to make. I'm a big fan of 550 cord (paracord). It's a must have item in all my tool kits.<br><br>I really like the idea of the knots. Makes sense
HiIlariouse!!!!! Your cable cam was funny!! how does one vote for you for the paracord contest or is it too late?
I'm glad you liked it. Unfortunately, the contest is over. But tell all your friends about it -- I just like the views!
Good stuff! Made one out of a kind size bed sheet and it was big enough to allow me to completely cocoon myself inside at night. I took it on a minimalist hike/camp trip over the weekend and it worked great! Much lighter than lugging in a tent/air mattress/etc.
I think the way to go for the minimalist approach is the bed sheet. You don't have to worry about sewing or fraying, and you can pick one up anywhere or just use one you have lying around. I may have to pick up a king size sheet. That sounds comfortable!
for an easier dissasembly you can also use a marline spike hitch after you do a round turn on the tree then when you r done you just pull the spike and wala! instant dissasembly.
I've thought of using a marline spike hitch, but was worried about it slipping over an entire night of sleeping. Maybe I'll have to experiment and see how it works.
&nbsp;This hammock is sooooo&nbsp;comfortable. &nbsp;Thank you for making this 'ibble. &nbsp;I made one today and i used a queen sheet folded in half and i works quite nicely. &nbsp;Keep posting paco!!! &nbsp; : )
&nbsp;I made one with a twin sheet, then decided I wanted a bigger one. I loved the king size, but after I used it twice, I heard a small rip as I sat down. Looks like the sheet is the weak link in the chain. I'm thinking of just buying a parachute hammock because they aren't too expensive.
What an awesome idea. Thanks for sharing:-)
&nbsp;i just made one...awsome! but my bro is kinda big and ripped the sheets...any suggestions for more strength?
How did he rip the sheets?&nbsp; Was it along the seams?&nbsp; In the middle?&nbsp; Were they thin sheets?<br /> <br /> It's hard for me to imagine someone ripping the sheets.&nbsp; That should be the strongest part of the design, as your weight is spread out over a large area of fabric, and where they connect to the paracord, they are bunched into essentially a very thick rope.&nbsp; Unless the sheets were very thin, old or already had a flaw in them, I really don't know how that would happen.&nbsp; I used some very thin material once (I could almost poke my finger through it) and although I stretched the fabric, it didn't tear.<br /> <br /> The other option would be to go to Wal Mart and spend $4.50 on 9 feet of thicker material.&nbsp; Sorry -- I didn't think that was going to be a problem.<br />
&nbsp;down the middle..,..but thanks for the suggestion
Re: Tree damage<br /> I&nbsp;usually place several dead branches between the tree and my ropes. This way the tree is untouched by the ropes and my hammock is just as secure. I leave happily rested and the tree leafs happily.<br />
That's a great idea.&nbsp; The dead branches disperse the weight and any cutting happens to the branches instead of the tree.&nbsp; That eliminates the need for carrying extra weight as padding.&nbsp; Thanks!<br /> <br /> One question -- how many branches do you generally use per tree?
Depends on the diameter of the tree. Generally enough to keep the ropes from touching the tree where they're spaced apart. If the rope touches the tree in a place, add a stick there.<br />
I think 2 pieces will be quite enough for this. BTW the rope wont wore down as quick as without branches!&nbsp;
&nbsp;I've always wanted a hammock but never wanted to bother paying 30$ for one of those parachute material ones. This is perfect!&nbsp;<br /> (the physics lesson was an added bonus too)<br />
I love mine.&nbsp; And it's so much more fun to build it yourself than to use a store-bought hammock.<br />

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