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Learning to use a hi-start

Old 11-20-2014, 11:47 AM
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Just came across a hi-start at Horizon hobby. FYI
http://www.horizonhobby.com/parkzone...0-2-3m-efla650

Includes a good video on how to use a hi-start
https://www.youtube.com/watch?v=ru0tyLi6L74#t=43
Old 12-17-2014, 01:09 PM
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Thanks
as much as I hate to admit it have the video instead on the narrative helped. Trying to remember what we did back in the 70s that turned my windward wing into toothpicks.
Old 12-21-2014, 01:19 PM
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Question Special Considerations for Short Up-Start Launch / Constrained Venue

>>High Reliability / Short Up-Start Launch Considerations?

So my at hand venue is a smooth, sandy seacoast beach which is often deserted in the Spring and Fall -- BUT, I also only have about 200' at low tide and sea breeze is obviously onshore.

The good news is that there may be some thermal possibilities due to differential land/sea heating which induces the seabreeze... plus there's likely a mini-slope effect near the dune line which seems worth exploring

The hope is that I only need to get 100-150' or so of altitude on launch to explore the thermal and slope possibilities. Am wondering if a shortened (100-150') Up-Start rig might do the trick for a 2.2m Parkzone Ka-8 that I just picked up... specifically considering the heavier duty version of the Up-Start from GP with the thicker tubing which is advertised for up to 100" wingspan (vs. the lighter "2m" version).

Are there any special launch considerations when using a short rig?... I don't think I need to go to high tension and, given that I'll be 'feet wet' at the release point would prefer to minimize risks associated with launching towards and over water... much appreciate any tips for achieving highly reliable launches by getting incrementally more comfortable. I don't think I can launch at too low a planned release altitude, if I'm going to have some room to abort a bad launch and get back over the beach.

>> PLAN B: Quadcopter Tow, or Lift & Release?

Another thought I've had for this venue, is to use a stabilized quadcopter to aerotow or lift the Ka-8. Most of the Youtube vids that I've seen have been a bit horrifying -- usual approach has been to drag the glider up vertically by the nose with a 'drop' release from pure hover. Best outcomes have been flyable but only after a big loss in altitude due to recovery needed... and then there's the crash risk from entanglement of the towline in the quad's blades.

I expect it might take a fair amount of practice for a team to establish a nice aerotow profile with a quadcopter -- would need to be smooth to avoid gyro induced oscillations... and might be something best done with wind as this could enable a protocol where the quad pilot maintains near zero ground speed and can focus on the ascent dynamics.

The need for two accomplished pilots (something I won't have often), for me, seems to argue for mounting the glider on the quad with CG aligned and flying the quad in a forward climb by making use of the glider aerodynamics principally for lift -- sort of a quad-assisted take off, or perhaps. a winged-quad concept. Release likely makes sense at altitude with the quad in level forward flight at a modest airspeed in the range of that for hand launch of the glider.

Given that we're exploiting lift from the glider's wings, a pretty modest quadcopter might be all that's needed -- indeed keeping the quad's blades near the wing roots so the rest of the wing can fly in relatively undisturbed air would seem to make sense (vs. brute force). I'm also speculating that control over altitude and direction could be substantially controlled by the quad -- so from the perspective of piloting the quad, this really would be the equivalent of putting a pair of wings on the quad -- something I might be able to practice initially with some spare free flight wings.

Welcome any thoughts, experience, comments that folks might have on either the short Up-Start or copter launches (multi-rotor or helicopter?)... or other approaches to getting my Ka-8 up off the beach, while avoiding landing out -- as in -- LOW (on the water without floats ;-) )...
Old 12-21-2014, 08:26 PM
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No special considerations for a shorter hi-start. I have two. One is 100 feet of rubber and 400 feet of line. The other is 25 feet of rubber and 100 feet of line.
Old 01-04-2015, 09:16 AM
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Another option for hi-start rubber is a pharmacy or medical supply store if you have one in your area. I know that this is about hi-starts but have to throw these few pics in. This is when we don't have much Thermal activity and the wind isn't blowing for the slope.
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Old 04-30-2017, 05:59 PM
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Over time I see fewer and fewer people using hi-starts. At our club it is either winch or electric. So I pulled out my hi-start just for fun. I was flying my Supra which is a molded wing competition glider made for the winch. But it still launches very nicely off my hi-start.
Old 12-26-2018, 09:12 PM
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Anyone have recommended source for hi-starts these days?

I see https://www.aerofoam.com/highstart-bungees.html Still has top quality products for sale.
https://www.aerofoam.com/highstart-bungees.html

I see Tower is still selling one but no specifics.
https://www.towerhobbies.com/cgi-bin...?&I=LXHNZA&P=7

I see Amazon has a silicone rubber hi-start for sale. 10 meter section. The old Latex were usually stretched to 3x their rested size. This claims you can go to 6X but no info on how much pull that produces. The suggest you can launch a glider up to about 6.5 pounds.
https://www.amazon.com/Bungee-Silico.../dp/B01N8XHUWI

Latex rubber up to 58 feet long
https://www.amazon.com/Rubber-Tubing...E4F&th=1&psc=1

Hobbyking has 10 mm Silicone rubber
https://hobbyking.com/en_us/hobbykin...tart-cord.html
Old 09-18-2022, 11:36 PM
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Default Micro Bungee for small gliders

Hello,

Just found your detailed hi start thread and would like to contribute in it, presenting my own design micro bungee for small gliders. This project was initially materialized for the needs of my also own design micro sailplane, the Micro Nova, but it can also be used on most micro gliders, suitable wingspans from 80cm to 120cm.

Since i am new at your forum, i cannot yet upload any photos... so will get back with photos as soon as i am able to.

Regards,
Kazaklis Tasos.


Old 09-18-2022, 11:50 PM
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The bungee is modular and consists of three separate parts:
- Special cut Latex surgical tubing (1/4 inchx1/16 half disc section with high elasticity 400%). Length is 6.5-8 meters (varies depending on application)… perfectly split/cut tubing from fresh production batch ensuring longevity… ends equipped with a strong ring and heavy duty swivel.

- Two separate line reels made of XPS and very practical to use with removable axles and easy engage/release line fittings. Line spools of 25 and 35 meters utilizing high elasticity/ yellow colored 0.6mm line… end fittings easily engaged in pennant and bungee end.

- Nylon pennant… its line ends equipped with heavy duty swivel and a small diameter tow ring.

In actual practice this micro bungee offers easy 5min deployment and retrieval… depending on conditions the short of long line can be interchanged easily thanks to the end fittings…very practical to use/ store ensuring hassle free launches of your mini sailplane… Instructions on proper use and tips on launching/model trimming included.

Only item additionally required is a ground anchor/stake that I deliberately omit from the package as its heavy weight and length would only increase shipping cost… a stake is really a low cost item and easily obtainable on most hardware stores so it’s best to obtain one from your end.


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