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#21
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Glider Winch Manufacturers or Plans to make???
On Jul 14, 6:26 am, Derek Copeland
wrote: About the only similarity between a Skylaunch winch and a Gerhlein is that they both use V8 gasoline engines with an automatic gearbox. The Skylaunch has benefitted from 40 years of development, is well designed and properly engineered, and is built to be heavy enough that it cannot be pulled into the air or toppled over by heavy modern GRP two seater training gliders, unlike the little Gerhlein. Bill Daniels' argument is like saying that the latest Ford automobiles are no better than a 1920's Model T because they share the same basic components! In Europe Skylaunch winches are considered to be state of the art, and a well proven design. They are often bought by clubs in preference to the stepless diesel-hydraulic and electric winches favoured by Bill. The latter are in theory better, but are considerably more expensive and don't work any better in practice. Economics and proven reliability do come into the argument as to which design to choose! The current manufacturers of glider winches are Skylaunch (UK), Tost (Germany), MEL (Holland), Hydrostart (Holland), Herkules (Czech Republic), Electrowinch (Germany), Egger (Germany), Integrale (Germany), Supacat (UK), plus the two US designs described below which (as far as I am aware) are both still under development. A quick 'google' should find you all the relevant web sites. Derek Copeland At 13:33 13 July 2008, Bill Daniels wrote: The skylaunch is a cosmetic update of the 1960's US Gerhlein winches and suffers from the same major shortcomings. If you still like it, save $50k - $75k by spending a couple of thousand for an old Gerhlein and fix it up. If you'd like a modern, state of the art winch, take a look at these from US winch buiders: http://www.romansdesign.com/ and http://www.hydrowinch.com Bill Daniels The Skylaunch is indeed simple engineering - deliberately so. IMHO the two clever things that Skylaunch did we firstly, to realise that the torque curve and response to load characteristics of the GM V8 gasoline/lpg engine are more suited to the throttle-limiter method of setting the power of the winch (for glider type and wind component) than are the characterisitics of the typical non-electronically controlled large diesel engine. secondly, to work out the appropriate throttle stop settings for all the likely gliders and wind components. John Galloway |
#22
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Glider Winch Manufacturers or Plans to make???
Ian wrote:
On 14 Jul, 00:48, Marc Ramsey wrote: Or, if you value your time at more than $5/hour, you can simply buy a Skylaunch at some level of completion and finish it off with locally sourced components. I thought Skylaunch - being sensible people - would sell neither winches nor plans in the US. Product liability and all that. They've been advertising in Soaring magazine for a year now, and in face to face discussion indicated that they'd be happy to sell us anything from a single component to a complete winch... |
#23
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Glider Winch Manufacturers or Plans to make???
On 14 Jul, 15:55, Marc Ramsey wrote:
Ian wrote: On 14 Jul, 00:48, Marc Ramsey wrote: Or, if you value your time at more than $5/hour, you can simply buy a Skylaunch at some level of completion and finish it off with locally sourced components. I thought Skylaunch - being sensible people - would sell neither winches nor plans in the US. Product liability and all that. They've been advertising in Soaring magazine for a year now, and in face to face discussion indicated that they'd be happy to sell us anything from a single component to a complete winch... I am corrected. Thank you. Ian |
#24
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Glider Winch Manufacturers or Plans to make???
At 09:41 14 July 2008, Tony Clark wrote:
I still await detailed clarification regarding the Skylaunch "shortcomings" with much anticipation! Don't worry Tony! I am pretty sure that we are about to get a load of guf from Bill Daniels about gear changes, torque multiplication, tension logs and tension spikes, with dark hints that the latter are somehow dangerous, but without any hard quantitative evidence or clarification as to why! Derek Copeland |
#25
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Glider Winch Manufacturers or Plans to make???
At 18:11 14 July 2008, Derek Copeland wrote:
At 09:41 14 July 2008, Tony Clark wrote: I still await detailed clarification regarding the Skylaunch "shortcomings" with much anticipation! Don't worry Tony! I am pretty sure that we are about to get a load of guf from Bill Daniels about gear changes, torque multiplication, tension logs and tension spikes, with dark hints that the latter are somehow dangerous, but without any hard quantitative evidence or clarification as to why! Derek Copeland Glider winches should be simple, in general they are driven by simple people. Probably the best winch I have driven or launched on is the Munster Van Gelder. This winch provided an excellent launch, was very simple to operate BUT it was heavy (8 tons with cable fitted) and technically complicated to the extent that a simple failure of a small cheap part could make it u/s. Far to complex. It could sink into a grass airfield with ease, getting it out was a different story. The Roman wich looks like a cut down Van Gelder and the Hydrowinch looks even more complex. The beauty of the Skylaunch is it's simplicity, modular easily accesible main components, engine gearbox and drive gear. Driving a winch should be viewed as a skilled occupation, far too often it is the lack of training and unsuitability of winch drivers rather than the equipment itself which causes problems. Good winch operation comes with experience operators and no amount of technical wizardry can make up for that. Buy the skylaunch and then get someone who knows about driving winches to train the drivers, someone with a proven record, not someone who thinks they know. |
#26
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Glider Winch Manufacturers or Plans to make???
I think you're wrong about the Skylaunch gear changes Derek! Our winch has a torque converter, but I don't think it changes gear during the launch! Or perhaps it does, but it's just that I have never been aware of it! Tony Clark |
#27
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Glider Winch Manufacturers or Plans to make???
At 18:56 14 July 2008, Tony Clark wrote:
I think you're wrong about the Skylaunch gear changes Derek! Our winch has a torque converter, but I don't think it changes gear during the launch! Or perhaps it does, but it's just that I have never been aware of it! Tony Clark Major shortcoming is: It's not here. Not close to our gliderport in SE Tennessee, USA. |
#28
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Glider Winch Manufacturers or Plans to make???
Actually the Skylaunch comes as standard with a 3 speed changing automatic
GM TH400 gearbox. I drive Tost winches which have been retrofitted with these gearboxes and I agree that the gear changes are not particularly obvious to the winch driver, or to that matter to the pilot being launched. With a sensible axle ratio the change from first to second happens very soon after 'all out' and the change from second to top during the ground run. If you listen carefully from outside the winch during a launch you can hear them as a change in the engine note. A changing gearbox gives a more rapid ground acceleration for heavier gliders, and allows higher gearing in top for a greater range of cable speeds without cooking the fluid in the torque converter getting the glider moving. Derek Copeland At 18:56 14 July 2008, Tony Clark wrote: I think you're wrong about the Skylaunch gear changes Derek! Our winch has a torque converter, but I don't think it changes gear during the launch! Or perhaps it does, but it's just that I have never been aware of it! Tony Clark |
#29
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Glider Winch Manufacturers or Plans to make???
Robert Gaines wrote:
At 18:56 14 July 2008, Tony Clark wrote: I think you're wrong about the Skylaunch gear changes Derek! Our winch has a torque converter, but I don't think it changes gear during the launch! Or perhaps it does, but it's just that I have never been aware of it! Tony Clark Major shortcoming is: It's not here. Not close to our gliderport in SE Tennessee, USA. That could be fixed 8^) |
#30
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Glider Winch Manufacturers or Plans to make???
To hear the gear changes watch and listen to the following video:
http://uk.youtube.com/watch?v=3PBcfahq4OU N.B. The first launch is carried out by a Tost winch with a non-changing automatic gearbox fixed in top gear. The rest are all with changing automatic gearboxes. Derek Copeland At 19:26 14 July 2008, Derek Copeland wrote: Actually the Skylaunch comes as standard with a 3 speed changing automatic GM TH400 gearbox. I drive Tost winches which have been retrofitted with these gearboxes and I agree that the gear changes are not particularly obvious to the winch driver, or to that matter to the pilot being launched. With a sensible axle ratio the change from first to second happens very soon after 'all out' and the change from second to top during the ground run. If you listen carefully from outside the winch during a launch you can hear them as a change in the engine note. A changing gearbox gives a more rapid ground acceleration for heavier gliders, and allows higher gearing in top for a greater range of cable speeds without cooking the fluid in the torque converter getting the glider moving. Derek Copeland At 18:56 14 July 2008, Tony Clark wrote: I think you're wrong about the Skylaunch gear changes Derek! Our winch has a torque converter, but I don't think it changes gear during the launch! Or perhaps it does, but it's just that I have never been aware of it! Tony Clark |
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