James Humphreys 1 Posted February 2, 2022 Share Posted February 2, 2022 As per the title I'm after a tug tow line release I've had a look around but can't find anything, if anyone has seen anything let me know cheers. Quote Link to comment Share on other sites More sharing options...
Wookman Posted February 2, 2022 Share Posted February 2, 2022 Have a look on Scale Soaring, there is loads of info on there. https://scalesoaring.co.uk/aerotow-releases/ 1 Quote Link to comment Share on other sites More sharing options...
Trevor Posted February 2, 2022 Share Posted February 2, 2022 It’s sometimes easier to make your own, e.g. 1 1 Quote Link to comment Share on other sites More sharing options...
James Humphreys 1 Posted February 3, 2022 Author Share Posted February 3, 2022 Cheers guys? Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted February 3, 2022 Share Posted February 3, 2022 Powerful servo with the release rod as close to the servo centre as possible, while only needed very rarely, when you do need it to release a hung up out of control glider it has to work. 2 Quote Link to comment Share on other sites More sharing options...
John Minchell Posted February 5, 2022 Share Posted February 5, 2022 James, Gliders Distribution do various ones for the glider end and may also have (but not on the website) tug ones. I got a 6 bolt flange fitting tug release from Stuart Mackay models - don't know if he is still trading. Also made my own as well - can take some pics if you need to copy it. John M Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 5, 2022 Share Posted February 5, 2022 This is mine in my Sig Rascal Quote Link to comment Share on other sites More sharing options...
flight1 Posted February 5, 2022 Share Posted February 5, 2022 If you don't want to make one wheelspin models do and make it build it also , but as said before a strong servo and strong jam not mechanism is a must . other sell them but i can't find at the moment Quote Link to comment Share on other sites More sharing options...
flight1 Posted February 5, 2022 Share Posted February 5, 2022 Hi could not edit previous post for some reason but i remembered . I new there was a cheaper version look for Ripmax WOT 4 XL/Xtreme Aerotow Unit A-CFWOT/TOW about £12 i think leeds model shop sells it too. Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted February 5, 2022 Share Posted February 5, 2022 (edited) I use this on my Wot-4 XL. Homemade from some 6mm ply and a spare U/C saddle clamp. The tow line is attached to the keyring. The assembly is held in place by the wing bolts. It's simple, it's tried and tested and it works. It would only be needed if the glider gets into difficulties. You don't want the tug to be dragged down with the glider so a flick of the switch and you're free.... Edited February 5, 2022 by Brian Cooper Quote Link to comment Share on other sites More sharing options...
J D 8 Posted February 5, 2022 Share Posted February 5, 2022 I like that, just fix on with wing bolts when needed.? 1 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 5, 2022 Share Posted February 5, 2022 Does it work under load with the small servo? In the full size world, several tug pilots were unable - or found it extremely difficult - to operate a release under load - a kiting glider can exert a lot of force. In one case at my club, the rope broke at literally the last moment and the Chipmunk was severely damaged as it pancaked but happily the tug pilot survived virtually unscathed. It's quite likely not all were so lucky. Releases were redesigned with over-centre locks to make release easier in an emergency - coupled with weak links, safety was certainly improved. Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted February 5, 2022 Share Posted February 5, 2022 (edited) 34 minutes ago, Martin Harris - Moderator said: Does it work under load with the small servo? In the full size world, several tug pilots were unable - or found it extremely difficult - to operate a release under load - a kiting glider can exert a lot of force. In one case at my club, the rope broke at literally the last moment and the Chipmunk was severely damaged as it pancaked but happily the tug pilot survived virtually unscathed. It's quite likely not all were so lucky. Releases were redesigned with over-centre locks to make release easier in an emergency - coupled with weak links, safety was certainly improved. It was tested by towing and releasing a glider which weighed about 10 pounds. It worked every time. It would be easy to fit a bigger servo for greater peace of mind. Edited February 5, 2022 by Brian Cooper Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 5, 2022 Share Posted February 5, 2022 Sounds good. The sort of situation I was thinking of was with the glider way out of position pulling very hard on the release bar. It was a very serious situation on full size as the attachment point was below the rudder and a glider could easily overpower the tug’s elevator if it got too high - especially with a belly hook, putting the tug into the ground very quickly. I lost a good friend to this. 1 Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted February 5, 2022 Share Posted February 5, 2022 The other area the tow release needs to work is on take off, I've been at a couple of aerotows were a glider has got hung up on take off, i.e. caught a wing tip in and swung round, the glider pilot hasn't been quick enough with his release and the tug pilot has had to rely on his release to allow the tug to get safely away While there's not much load on the release under normal operation where you throttle back before releasing to take the tension off, it has to work under the extreme conditions when you really need it. 1 Quote Link to comment Share on other sites More sharing options...
John Minchell Posted February 6, 2022 Share Posted February 6, 2022 Normal aeroplane - you need the best quality and torque servo on elevator. A tug needs the highest torque servo on the tow release and same or next best on elevator. The rudder on a tug may also need a grunty servo if the tow line can pull against it but you still need the rudder to work against the side load of a glider on tow. Applies to the glider as well. ( strongest servo on aerotow release). Oh, and don't be tempted to use a retract servo - they are too slow to release after you have flicked the switch - don't ask how I know that! 1 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 6, 2022 Share Posted February 6, 2022 This quickly knocked up diagrammatic representation of the sort of thing I was thinking of would remove all holding load from a servo, while allowing release under any amount of tension with minimal servo torque required: Moving components shown in green for towing positions and red after emergency release operation. First pivot from servo allowed to sit slightly over centre in towing position. Floating pivots shown in black. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 7, 2022 Share Posted February 7, 2022 Maybe the Tost system could be used in a tug? https://scalesoaring.co.uk/tost-release-system/ Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 7, 2022 Share Posted February 7, 2022 Similar interpretation of the same principle that I vaguely remembered - looks well designed and constructed. I like the manual release idea. Perhaps I'll try knocking up a working example of my solution if I get time...I could make use of a tug from time to time. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.