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MY ZIP LINE - PAGE 4
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THE PLATFORM & OTHER NOTESThe ladder was obviously not going to be good way to launch from the zip-line, so we built an elevated platform which works really well: Peter puts the final nails in the platform decking.
This thing cost around $175 in lumber, bolts, nails, screws, and such. It is built entirely out of pressure treated lumber, using 4x4's for the posts, 2x6's for the load-bearing header beams, and then 2x4's for all the cross supports, ladder, and joists. The decking was made from 6" wide decking planks. The only probem with the platform was that we built it too high. After building it we tried it out only to find that when weight was put on the zip-line it dipped so low that you'd hit the end of the platform. So, we realized that we either had to raise the zip-line or get a bunch of friends over to lift the platform so that we could cut off about 2' on each leg. Raising the zip-line seemed like a better idea, and it was. We unscrewed the turnbuckles and released the cable. Then we raised the launching end up almost 2' on the tree (once again, good thing we used a sling and didn't drill an eye bolt permanently through the tree!). While we were at it, we also raised the bottom end of the zip-line about another foot. Reconnecting the cable to the turnbuckles was a challenge, but we learned a trick which worked quite well. It became quickly obvious that there was no way we were going to be able to just pull the cable back over to the turnbuckle - the weight of the line was causing way, way too much tension for us. So, we got some old rope, tied it to the end of the cable and then connected a carabiner to the turnbuckle and ran the rope through it. This way we could pull on the rope which would pull the cable closer to the turnbuckle, but the caribiner gave us some much needed leverage to accomplish this. While I pulled the cable, my brother got ready to put the bolt through it to connect it. Here's an out-of-focus picture of the rig once we got it pulled together: Our rig to re-connect the cable to the turnbuckle
This worked perfectly! The line was now high enough so that the rider would clear the platform, and the extra height provided a much longer ride. We got it so exact that's is scary. With no braking, the rider will come within just about 2 feet for the tree at the bottom and then stop and roll back. Absolutely perfect!
So, here are more movies of the zip-line after we completed the launching platform and fixed the height of the zip-line: |
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©2011 Brian Greenstone