Winching - Reverse Auto Tow

On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this.. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability....particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead