Winch, Hi-Start, Up-Start, Zip-Start, Bungee, Zoom??
When thermal soaring, you need some method of launching unless you have a handlaunch glider (HLG). The main options are a Winch, Hi-Start, Up-Start, Zip-Start and Bungee. For a description of a winch and a hi-start, see R-C Sailplanes. For an illustration of a winch launch, see Soaring League of North Texas. That page depicts a launch where someone was too heavy on the pedal, destroying the plane. Picture the plane coming loose from the line and sailing off instead.... A good drawing is at Extreme Products.
Here is a question from the rec.models.rc.soaring newsgroup and the answers which should explain what the the variations of a hi-start are:
QUESTION: (Albert Vallone)
> >In the lexicon of soaring I have seen the terms Hi Start, Up Start, and
> >Bungee used almost interchangebly. There deesnt seem to be any
> >standard. Are there different configurations?
> A histart is piece of tubing around 100 feet with about 400 ft of line
> connected to it. An upstart is a smaller version with 50 ft tubing and 150-200 ft
> line, and a bungee is just the tubing, probably around 50 ft. A zoom launch is
> about 20 ft of tubing and maybe 10-30ft line if at all.
[Note from David: these are typical lengths of tubing and line, there are many variations.]
FOLLOW-UP ANSWER: (David Cole -- yep, that's me....)
I've also heard that in some places outside the USA they call a hi-start a
bungee -- Joel's descriptions are correct for the USA.
Another version is a zip-start, which is about 10 feet of small tubing and 20-30
feet of line. Many handlaunch glider (HLG) pilots use a zip-start to get about
the same launch height as a good hand launch. In our club, zip-starts are
always an option in HLG contests, as we have several older guys and people who
have thrown out their shoulders. Our club has a number of zip starts with the
same tubing and a limiting line within the tubing so they can only be pulled
back a certain distance, thus evening the field.
Where to buy
For info on where to buy hi-starts and tubing of all sizes, see my Sailplane Links page. There is a section titled "Hi-start and tubing links" on that page.
I have a Pinnacle M hi-start (100 ft tubing, 400 ft line) for my 2-meter, a Pinnacle S up-start (50 ft tubing, 200 ft line) for my 1.5 meter HLGs, and a zip-start (10 feet tubing, 20 ft line) I made for my 1.5 meter HLGs using tubing from Hollyday. All three are great, but there are less expensive choices available. I also have a zip-start made with tubing a friend gave me -- it is the exact same tubing the other guys in my club use for their zip-starts, allowing us to even the playing field for our friendly all-up-last-down handlaunch competitions we do over and over when we are all flying handlaunch.
Here are the specs on my hi-starts:
Pinnacle M hi-start 100 ft tubing 400 ft line Tubing is 5/16" OD, 3/16" ID, 1/16" wall thickness, color is red
Pinnacle S up-start 50 ft tubing 200 ft line Tubing is 7/32" OD, 1/8" ID, 3/64" wall thickness, color is red
Zip-start - black 10 ft tubing 20 ft line Tubing is 3/16" OD, 1/16" ID, 1/16" wall thickness, black Hollyday tubing
Zip-start - amber 10 ft tubing 20 ft line Tubing is 7/32" OD, 1/8" ID, 3/64" wall thickness, color is amber
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