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5.. Final question – towlines. Is there still a huge variation of
opinion on which is best or has a preferred type risen to the surface. I
would like to use Russian rod but am worried that it is too thick at 1mm
– the drag on the model when circling will knock enough out of the glide
with the line attached to make picking air difficult when lift is very
marginal (for me anyway). With an e-hook, a snapped line is not a lost
model anymore so provided it does not happen twice in one round the
consequences are not serious. I am tempted to try 50 kg Kevlar with a
leader of 15m Russian rod but am scared I will have no fingers left
after a while (less serious now that it is not necessary to build models
anymore but still required to earn the greater income needed to buy
them)Neil Murray posted by Jim Parker
Towline is a matter of personal taste. Can’t beat the russian rod
for simplicity, and lots of guys use it and get very high launches which
don’t seem to be bothered by extra drag. I like having a thick cord at
the bottom for easy handling and am currently using “pulse line” for
this, about 3mm stuff available in sailing shops, and then use spectra
on top.Final question – towlines.
A snapped line is not a lost model but it is a bad flight – especially in
round 6 of a big competition^&*)*(*&(*&^*&^%$%$#%$#@#@!@$%$^&&*(.
Russian rod is nice and non-stretchy but a pain on a rough field. Russian
rod is about 1 mm dia. Kevlar or spectra at the top end (~30 m) with softer
monofilament below is certainly good good for F1H and ok for F1A (and I
think it is now legal to have a joined line).
Finally. Zooming gliders all used to have conventional warps whereas, as you
noted Wakefields used “reverse warps” to aid thermal seeking (a hige topic
in itself). Now that differential is not required to control the zoom,
gliders can be set up with minimal (or even a touch of reverse if lower
aspect ratio). Models that are marginally spirally stable in the glide (R-L
rubber models, HLGs, F1Bs with reverse warps) do seem to thermal better.The russian rod, or polyester line, is 1 mm as you say. The stretch is minimal, but it has high energy storage. The yellow monofilament is also 1mm, and also the 200 # braided kevlar is 1mm. So all of these lines have the same drag.
So what is the diameter of the Spectra that you use Jim??
The only problem I have had with the polyester line is that it coils on the ground after launch and a chase bike invariably catches it in the chain and cuts it. This has happened twice now in 10 flights at Lost Hills. Never a problem on a sod farm with no chase bikes going through the launch area.
I was going to do some comparisons between the polyester and monofilament as far as launch altitude, but the wind came up as I was going to begin testing, and the next day my polyester got cut by the motorcycle. The yellow monofilament stretches 2 to 4 feet and takes a permanent stretch after each high tension launch, so theoretically, one should be chopping the line after every few flights.
I have not tried Spectra, and will have to give that a try.
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