Micheal, I see this as two different “zoom” situations. The first is where there is the shallow dive type of zoom that attempts to gain energy from the...
7012
derek_cirrus168
May 2, 2009 8:32 am
Even with a normal winch launch it is not unusual to gain another 50 to 100 feet after release, depending on the exact circumstances at the point of release....
7013
skmord
May 3, 2009 11:41 pm
Anytime you have extra speed above your flyaway speed when you release you can convert it to height. It has nothing to do with excess lift only conversion of...
7014
derek_cirrus168
May 4, 2009 8:30 am
Yes, but any excess speed is still potential energy that has been stored up during the winch launch. If you launch something like a K21, it's best winch...
7015
Michael Derry
michaelwderry
May 4, 2009 1:41 pm
Hi George Many thanks to your reference to post 4545 which has added to my knowledge on the subject. I have just tried to get into the files area of this group...
7016
George Moore
soargsm
May 4, 2009 4:55 pm
Hi Michael, In general the climb (in still air) should be performed at the best loaded L/D speed for the glider/parachute/cable system - this minimizes the...
7017
Udo Rumpf
udorumpf
May 4, 2009 8:10 pm
Hi, everything George said is true. since I have well over 1000 launches and 3 world championship from 1980 to 1987 in The FAI class F3B. I would like to make...
7018
derek_cirrus168
May 4, 2009 9:05 pm
In that case, what is the point of having a maximum winch launch speed (Vw)? The most it is for any normal glider is 81 knots (150kph), many are far less than...
7019
George Moore
soargsm
May 4, 2009 9:48 pm
Hello Udo, Thanks for the confirmation from practice. I would make one small correction to your post. With a true constant tension winch, diving would not...
7020
derek_cirrus168
May 4, 2009 11:23 pm
Hi All, I have posted a video of a short aerobatic sequence flown by a K21 off a fairly high, dead into wind, winch launch: ...
7021
Udo Rumpf
udorumpf
May 4, 2009 11:40 pm
Correct George, In my thought experiment, the tension would terminate hence a small dive to take the tension of the hook. (I am wondering If the Hook would...
7022
Udo Rumpf
udorumpf
May 5, 2009 12:04 am
I have design, base on Bill's feed in guide and sheaves, a pulley for auto towing, the one attached to the car is a 2:1 ratio and the other is the same but for...
7023
Udo Rumpf
udorumpf
May 5, 2009 12:24 am
I listed it as a word .doc file as well Udo...
7024
Michael Derry
michaelwderry
May 5, 2009 1:20 am
Dear George and others I gather that the maths for optimising speed, AOA throughout various stages of the launch is very complex however most of us can improve...
7025
Marc Ramsey
marc_5k
May 5, 2009 1:29 am
Hi Udo, You just tried to upload three files, the first one just has text (as far as I can see), the second two don't seem to have made it.... Marc...
7026
Udo Rumpf
udorumpf
May 5, 2009 1:56 am
Marc, One is an acad drawing file version 10, the other is a word doc. in both cases I can open it. This is why I posted the word file because some people can...
7027
Marc Ramsey
marc_5k
May 5, 2009 2:34 am
Yes, works now, for some reason the links in the notification messages didn't work when I first tried them......
7028
George Moore
soargsm
May 5, 2009 3:21 am
Udo, I think we are in general agreement. Regarding releasing under high tension, I do not advocate that. That was another reason for not doing the more...
7029
George Moore
soargsm
May 5, 2009 3:30 am
Michael, Thank you. I'm glad you found the discussion useful. I don't know the details of your winch but I surmise it is petrol powered probably with an...
7030
Michael Derry
michaelwderry
May 5, 2009 3:40 am
Hi George The winch is approx 30 years old and was made from an old diesel powered tractor engine probably 1950/1960's vintage. Although diesel it doesn't have...
7031
George Moore
soargsm
May 5, 2009 3:47 am
Michael, Thanks for the additional details. Does your winch employ a fluid clutch then? Unless it is loosely coupled so that it can keep up some revs when...
7032
Michael Derry
michaelwderry
May 5, 2009 4:19 am
Hi George Not sure fo the clutch system or other details on the drive system for this winch. I take note of your comments though. Cheers Michael On Tue, 05 May...
7033
Michael Derry
michaelwderry
May 5, 2009 4:25 am
Dear All Some gliders gain lots and lots of height from high speed pullups. From my limited knowledge it seems that the more efficient the wing the greater ...
7034
Udo Rumpf
udorumpf
May 5, 2009 9:35 am
Yes, you are right. I get 300 ft with 100 kt with my ASW 27, maybe a bit more. As an aside, lots of contest pilots are under the false assumption and think...
7035
derek.copeland45
derek.copela...
May 5, 2009 12:27 pm
How much height you get back from a high speed pull up depends both on the efficiency of the glider and its weight; the heavier the better because it will have...
7036
skmord
May 5, 2009 3:36 pm
Derek wrote: I used to own a share in a rather heavy, 21.9 metre, all glass fibre Nimbus 2. In a competition finish at 120knots, that would climb from just...
7037
derek.copeland45
derek.copela...
May 5, 2009 3:55 pm
George's height gain equation could be wrong of course! On one occasion I ended up at 1000ft AGL, but that may have been aided by a thermal. My current...
7038
Udo Rumpf
udorumpf
May 5, 2009 6:00 pm
I am sourcing C-Load cell and a simple digital display with 3/4 digits Best price so far complete $ US 860.00 plus tax and shipping. Any one know where I could...
7039
Marc Ramsey
marc_5k
May 5, 2009 7:34 pm
This place has some of the lowest prices I've ever come across: http://www.icscale.com/index.html I've done no business with them, so I have no idea whether...
7041
George Moore
soargsm
May 5, 2009 7:55 pm
Sorry, his time with the link. This one looks interesting and is around $400. http://www.icscale.com/p2000hang.htm Comes with 10 foot cable between sensor and...
