I found a great item on Amazon that will provide entertainment for our kids in our backyard. It is a Zip Line designed for kids. It is meant to be strung between two trees, supports up to 225 pounds and gives a maximum ride of 70 feet.
First is the height difference. Based on the instructions that came with the kit, for the 60 foot run, the zip line needs about 30 inches of height difference. The starting height should be about 102 inches and the ending height would be about 72 inches.
I used a laser level (SKIL MT 8201-Self-Leveling Cross Line Laser
) and a yard stick to measure the difference in elevation between the start and end of the zip line run in my backyard. Luckily, I had about 22 inches of elevation change. This means that I only need 8 additional inches of height differential for my set-up.Second is the tension in the cable. The kit uses 1/8" steel cable with a tension of 300 pounds with no load and 600 pounds maximum tension. It would be very difficult to set posts in the ground that could withstand that amount of force without bending over and losing tension.
I thought of two solutions to the tension problem. 1. Brace the posts with struts or wire anchored to the ground. 2. Have the cable anchor to the ground on both ends and go over the posts with pulleys. I chose option 2 since it seemed easier to implement.
Here is a diagram of my plans:
This design can be further improved by angling the posts away from each other by 5 or 10 degrees.
In order to setting up of zip line kits one must be aware of the various points should be kept in mind while the installation of the same. The above blog is very important for the various people to adapt a valuable knowledge about the same. For same visit here:
ReplyDeletehttp://stores.backyardziplines.com/-strse-Zip-Line-Kits/Categories.bok
how did this work? I have a similar problem
ReplyDeleteit works fine. i haven't had any problems. be sure to place padding around the pole at the end of the run or install a stopper for safety.
ReplyDeleteI sketched the same concept. Without anchors the posts will just bend very quickly and you will lose tension. Instead of changing elevation in the ground, just bury one 4x4 post deeper than the other, if your yard is flat.
ReplyDeleteI used 4x6x12' pressure treated lumber with the anchors and pulleys shown in the diagram. I can maintain tension without causing any significant flex on the posts.You could utilize existing slope or bury one deeper as you mentioned.
ReplyDeleteHow large are the concrete anchors and how deep did you bury them?
ReplyDeleteI dug a hole 3 feet deep, 1 foot wide and 2 feet long. The long dimension was perpendicular to the cable direction. I placed a long rebar in the middle of the hole running the long dimension and two smaller pieces in thr ground to support it. I threaded the long rebar through the end link of a heavy duty chain that was 2' in length. The chain is the only thing sticking out of the surface. I filled with 80Lb Sakrete Concrete Mix which i mixed with water.
ReplyDeleteHow much did this project cost you? Would you be willing to list all products and tools needed to complete? Can all supplies be purchased at Lowes/Homedepot?
ReplyDeleteI am a mom, VERY interested in trying to make this come to life for my son; however, without any trees, I was at a loss before stumbling across your blog.
I wouldn't consider myself "handy," but I think I can handle this...maybe!
I'm literally in the middle of doing this project. I've spent $70 on two 6"×6"×12' wood post. I put about 400 lbs of concrete around both anchors and both posts, so probably $100 on concrete alone. $30 for the 100' 1/4" galvanized cable. Both pulleys I had but only cost $5 each. I had two 4' anchor that I buried in the ground and surrounded with 400 lbs of concrete. Still need to order the actual trolley which you can get sets for like $150. Basically you're looking at between $300 to $500 in my opinion.
ReplyDeleteI'm literally in the middle of doing this project. I've spent $70 on two 6"×6"×12' wood post. I put about 400 lbs of concrete around both anchors and both posts, so probably $100 on concrete alone. $30 for the 100' 1/4" galvanized cable. Both pulleys I had but only cost $5 each. I had two 4' anchor that I buried in the ground and surrounded with 400 lbs of concrete. Still need to order the actual trolley which you can get sets for like $150. Basically you're looking at between $300 to $500 in my opinion.
ReplyDeleteHow far away from the posts are the anchors?
ReplyDeleteThanks Alan.
DeleteMy posts are 10' above ground so i placed the anchors 10' away. The closer the anchors are to the posts, the higher force is generated and the higher chance of material failure.
ReplyDeleteI have one tree and one post in cement, do you think my post will need an anchor?
ReplyDeleteI would still think you'll need an anchor. This idea of this design is to take all the stress off of the post and put it on the anchor.
DeleteHi Alan, thank you so much for this blog, it has helped me out a lot and i am about 75% complete with this project. I had one more question for you. What did you use for a brake?
ReplyDeleteDepending on the speed there are different methods of slowing down and avoiding injury. For low speed, you can wrap the end post with padding. For higher speeds, you can install a "stop block" see link: http://amzn.to/1Fyr2PT . You will also need "shock cord" see link: http://amzn.to/1Hb88WN . You tie the shock cord to a fixed object or the ground. Search online for safe installation instructions.
DeleteI ended up using small tires, such as go cart or golf cart tires, run the zip through the middle of them so it looks like this ----O-O-O-O------, sorry for the crude example, but i think it shows a good representation. the tires will compress a bit and the zipper will swing up towards the tires a bit, but it provides a good cushion to stop.
DeleteSeems like a good solution. Its always nice to use stuff you have lying around!
DeleteWith only a 100 feet from fence line to fence line can you do this without anchors (anchors would go in neighbors yard :-) if there is not enough room to put the anchors in the yard without shortening the run by 10 feet on each side.
ReplyDeleteUse larger posts set in ground at angle with Deadman brace
DeleteIt really cannot be done easily without cables (or some other material) supporting the posts (guy wires). The tension on the posts could easily exceed 1000 lbs when there is a rider. If not supported properly, the posts will bend and the line will sag.
ReplyDeleteWould be lovely to see an actual picture of the finished product. Now 5 years since you installed !! My kids have outgrown the zip wire I installed between trees in the back garden (THE most fun thing even though they have everything else - well, except a swimming pool :|). Now I'm desperate to make a better one in the front where there are no trees. I'll be following these plans I think - thank you.
ReplyDelete