from the point the plane is flying until the apex it does you nothing to build up speed. If you keep the pedal to the metal you are just sucking in line.
Before you reach the apex you should start building speed.
As far as stretch in the line ... with braided there is hardly any stretch... it is there but not much. Mono on the other hand is a kick in the pants. yeeeee haaa :-)
Cambering is a great thing (full trailing edge)... you get lift, but you don't need speed to convert it... But you must get the camber off to realize the speed.
As you are reaching the apex you should be getting speed up...
__I never said tap until the zoom....__ if I wasn't clear here is my statement
"Tapping most of the way up will get you higher. Less line taken in.
Full pedal close to the apex and then into the zoom will accomplish the same zoom with reflex added to get the speed up. "
When you get close to the apex you should then go full pedal (no camber) then reflex just b4 the zoom. I didn't say tap into the zoom.
If it is done correctly you are not stressing the line since you are now converting lift (camber slow tapping) into speed (no camber )... the lift generated at speed is substantial but if you are going for zoom you are probably( holding a slight amount of down (very very slight) or reflexing ) to get the speed up because of the added lift (during speed) ... NOW if it's mono.... you stretch the line before the zoom... but you can't do that with braided! so a more efficient launch gets the speed up.. If you keep the lift (camber, back stick, or neutral stick ) on and speed on you will break the line...If you are willing to trade speed for lift you will be safe and usually not break the line and have a great zoom.
For MONO go ahead and stretch..... (yea baby)
John Erickson wrote:
Jeff,
With all the telemetry available now it would be an interesting study to see what results in the highest launch. In my opinion the most important factors are the wind or thermal activity, the stretch of the line, and the strength of the airframe.
The whole point about cambering the wing and getting lots of tension initially is to get the most potential energy out of the line. If it can't all be created to kinetic energy at the zoom, then it is just a case of burning out brushes on the winch. I always shake my head when I see someone really tension up, full pedal, then fly off at the wrong time without a zoom, maybe just a flat trajectory going a little faster.
Dr. Drela did some launch sims comparing 6 volt and 12 volt winches. The most important factor was the speed at the top of the launch. If you can do it with tapping, great. The sim indicated that full pedal was the best way. There are a lot of other factors he put into the equation, such as line elasticity, line diameter (resultant drag on the line), weight of the plane, drum diameter, etc.
You can find the results here: http://groups.yahoo.com/group/Allegro-Lite/files/Winch_Launch/
I hear what everyone is saying about the lost art of winching a fragile
plane. I have a Bird of Time that would most likely fold the wings under a
full pedal winch into a 10 mph headwind, yet it goes up fine without damage
if I tap carefully and don't zoom too hard. The Icon, on the other hand,
can take just about any kind of abuse. Because it is F3J related, the idea
is to get off the line quickly, hence lots of tension and smoked winches (I
know, I'm the club equipment manager).
JE
--
Erickson Architects
John R. Erickson, AIA
From: Jeff Steifel <[EMAIL PROTECTED]> Date: Wed, 18 May 2005 08:54:42 -0400 To: RCSE <[email protected]> Subject: Re: [RCSE] OVSS and Line Breaks
Let's discuss launch for a minute. I think TK hit on something that gets
lost: technique.
Why do guys do pedal to the metal launches?
Is it to get more altitude?
More zoom?
Trash the brushes on the winches?
-- Jeff Steifel
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