hand tow pulley

[southern soarer uk]

Me and my flying buddy have recently got back into hand towing and whilst flying on sunday were reminded by one of our club members of a hand tow method he uses where you can tow on your own . The end of the tow line is pegged out approxamatly 10metres in front of you the line then runs back towards you and over a pulley attached to your belt it then travels about 150metres to another pulley and back to you where you hook the model on then walk backwards to tension the line , as it`s on a pulley system you have a ratio of 2 to 1 so less effort is required , he has lent me the pulley to clip on my belt but i`m trying to source one for myself can anyone help? i`m looking at something UK based , see picture for details of the pulley it`s approx 90mm acroos and 25mm thick, thanks Harvey

[dwells]

Hi Harvey,

It looks very simple and can probably be fabbed easily. You could take a pair of Duncan Butterfly yoyos, pull out the shafts, glue the halves together, drill them out and fashion the axle/belt clip from pin stock or all-thread or something.

Don

[rogerflies]

Try this forum:
http://bbs.homeshopmachinist.net/forumdisplay.php?f=3

It's for home shop machinists. There are some very talented members from UK, and they may be willing to fabricate one or more of them for you. Just join up (it's free), and make a post to explain what you want to have done. Pictures always help. Be sure to have a self-explanatory title. Something like "Needed: UK machinist to fabricate several simple pulley assemblies. Pics."

If that's too involved, PM me your email address so I can make the post for you.

Roger

[dmt]

Me and my flying buddy have recently got back into hand towing and whilst flying on sunday were reminded by one of our club members of a hand tow method he uses where you can tow on your own . The end of the tow line is pegged out approxamatly 10metres in front of you the line then runs back towards you and over a pulley attached to your belt it then travels about 150metres to another pulley and back to you where you hook the model on then walk backwards to tension the line , as it`s on a pulley system you have a ratio of 2 to 1 so less effort is required , he has lent me the pulley to clip on my belt but i`m trying to source one for myself can anyone help? i`m looking at something UK based , see picture for details of the pulley it`s approx 90mm acroos and 25mm thick, thanks Harvey


That's nuts, but I want to try it! I'd like to see a diagram (or better yet, a YouTube video!) of how this sort of setup woks.

[Sotir]

Me and my flying buddy have recently got back into hand towing and whilst flying on sunday ........

Don't forget to put plastic shield (25-30 cm diameter) as F3J pulley. Lines are very dangerous.

[Elmog]

How's bout' a schematic?

[MarkusN]

There you go.

[Elmog]

Thanks for the pictorial. So I guess you have to run backwards, eh? Probably not too bad once you get used to it.

[DT56]

text

[southern soarer uk]

When i`ve seen it used there has been some wind but i`m told it will work in no wind and with a ratio of 2 to 1 on the pulley less effort is needed

[rogerflies]

It would take a bit more line and another pulley, but you could always put a pulley behind you to run forward when launching.

Roger

[MarkusN]

Are you able to use this system in low or zero wind conditions?

I ask, because generally when a system of blocks is used to reduce effort, the output speed is reduced as well.
The system is not set up that way. Force on the pulley is actually increased; you have to pull twice as hard. Speed is doubled, so you don't have to run as fast.

Since attaining enough speed is usually the problem in hand tow and the force is no real concern you could still claim that "less effort" is needed, just in a bit loose sense of the term.

As for running forward: The main use of the system is if you want to launch on your own. Since both R/C and release of the plane are virtually impossible going forward, I think that's not really an option.

And as running backward certainly ain't easy I thinkt it's limited to planes that are happy with rather slow towing speeds: Build up tension in the system for some speed reserve at initial launch, after that even in moderate wind fast walking at the pulley is usually all it takes.

[enrico74ec]

Try some used or replaced aviation fly line pulleys. They sometime replace them every X amount of time and work perfectly fine. Just not airworthy :rolleyes:

In any case, we did use this sistem with my dad and with just a fast pace walking we where able to seriously damage gentle lady and spirit 2 m wings. It worked perfect with a huge Sailaire also.

[wixy3]

southern soarer uk and others interested in flat field soaring in the UK .
As the UK f3j league co-ordinator I am always looking to encourage newcomers to
our great sport.
This season we have organised 2 f3j practice days /Clinics where we will have some of the UKs top Thermal pilots available to help and share their f3j secrets .
This will also include Towing, including safe practices as the correct equipment is essential to avoid injury.
Practice day 1 Easter Monday venue Ashurst ,Sussex.
Practice day 2 April 6th Isa field Bedfordshire.
For full detail please look at the WWW.BARCS.UK
All welcome .Wixy