Mechanical Advantage is a Myth


We all know friction in a mechanical advantage block and tackle pulley systems can reduce output, but I haven't heard anyone talk about stretch. I am always using semi static or climbing ropes, which have a lot of stretch. We test all the way up to a 13:1 with dynamic, semi static and 0 stretch dyneema. We did NOT use multipliers or brakes to simplify this already long experiment.

*All numbers are in kN. Trying to keep a lot of data easy to look at!

►►►DYNAMIC ROPE

►1:1 pulleys n/a - 1.34 INPUT x 1.19 OUTPUT / 100% vs Actual 88%

►3:1 with pulleys - 1.13 INPUT x 2.26 OUTPUT / 300% vs Actual 200%

►3:1 without pulleys - 1.19 INPUT x 1.99 OUTPUT / 300% vs Actual 167%

►5:1 with pulleys - 0.89 INPUT x 3.84 OUTPUT / 500% vs Actual 431%

►5:1 without pulleys - 1.39 INPUT x 2.38 OUTPUT / 500% vs Actual 171%

►9:1 with pulleys - 0.85 INPUT x 5.92 OUTPUT / 900% vs Actual 696%

►9:1 without pulleys - 1.12 INPUT x 2.38 OUTPUT / 900% vs Actual 212%

►13:1 with pulleys - 1.01 INPUT x 5.04 OUTPUT / 1300% vs Actual 499%

►►►SEMI-STATIC ROPE

►1:1 pulleys n/a - 1.62 INPUT x 1.26 OUTPUT / 100% vs Actual 78%

►3:1 with pulleys - 1.31 INPUT x 3.46 OUTPUT / 300% vs Actual 264%

►3:1 without pulleys - 1.72 INPUT x 2.48 OUTPUT / 300% vs Actual 144%

►5:1 with pulleys - 1.10 INPUT x 5.15 OUTPUT / 500% vs Actual 468%

►5:1 without pulleys - 1.18 INPUT x 2.67 OUTPUT / 500% vs Actual 226%

►9:1 with pulleys - 1.31 INPUT x 7.48 OUTPUT / 900% vs Actual 696%

►13:1 with pulleys - 1.4 INPUT x 6.98 OUTPUT / 1300% vs Actual 498%

►►►DYNEEMA ROPE

►1:1 pulleys n/a - 2.33 INPUT x 2.07 OUTPUT / 100% vs Actual 89%

►3:1 with pulleys - 1.34 INPUT x 4.04 OUTPUT / 300% vs Actual 301%

►3:1 without pulleys - 1.47 INPUT x 2.97 OUTPUT / 300% vs Actual 202%

►5:1 with pulleys - 1.67 INPUT x 6.71 OUTPUT / 500% vs Actual 402%

►9:1 with pulleys - 1.47 INPUT x 9.62 OUTPUT / 900% vs Actual 654%

►13:1 with pulleys - 1.51 INPUT x 8.54 OUTPUT / 1300% vs Actual 565%

►►►THOUGHTS:

*** % wasn't that different but my input is so much greater not fighting stretch

***9:1 is better than a 13:1 and might be worth using, but a 5:1 is the most optimal to get as close to theoretical as possible


😀😀😀DISCOUNT GAME:

👉 24% off all pulleys for 24 hours on https://www.extremegear.org/shop/hard...

👉 Discount code is found in the book of numbers in the Bolting Bible https://www.hownot2.com/boltingbible

👉 10% of your purchase (of non-sale items) supports this channel and the rest goes to Cave Exploration Society, the non-profit that owns and operates ExtremeGear.


►10% off at https://rockytalkie.com/products/rock...using the code "HowNOTtoHighline" ►Perfect Descent Auto Belays I use on my drop tower https://tinyurl.com/2p9davdj

►Balance Community has great slackline gear https://bit.ly/351FSFO

►Shirts and hats (NEW IMAGES COMING SOON) - https://www.SLACKLIFE.store

►LineScale 3 - https://www.linegrip.com/shop/linesca...

►I love my Rode Go II Audio https://amzn.to/3ftU27P Buy anything else after clicking this amazon link I'll get a commission and I may not have to paint houses anymore!


👉Amazon carabiners video https://youtu.be/sBEhKh_3xtM

👉Making a living on ad revenue is a myth https://youtu.be/m8z6adEqaOs

💲💲💲We are still 100% dependent on donations until you buy a lot from Extreme Gear :) Please donate at https://www.HowNOT2.com/donate🙏🙏🙏


Behind the Scenes

abc


After Posting Thoughts

abc

© 2022 By HowNot2 - All Rights Reserved
Disclaimer - Terms of Use - Privacy Policy

Breaking Gear Fear

Edutainment has been a great way to help people understand their gear, and know the true limitations of it.  Watching HOW gear fails is more important than the force itself, as almost all gear is super good enough.  It's more important to share information on how to stay safe than it is to have a paywall.  We hope our stoke is contagious.