I have a similarly constructed high start, I used heat shrink for the end wraps instead of tape.

Sorry, I got lost somehow.
Are you anchoring 2 bungees to two separate ground anchors then both of the other ends of them to a single bungee with the 60m of rope with the parachute on the end of that?

I believe that is correct. That provides a little extra safety in case one of the anchors or line fails.

So as I understand it, this a 'Y' configuration, with the tail of the Y connected to the towline-'chute-glider. Correct?

It's being discussed in another thread. Someone posted a diagram at my request. Not a Y. Just 3 strands so that one can break without endangering the pilot.

Diagram

The idea being that 1 strand is dangerous, 2 strands is better, but if one breaks it's possible for the 2nd one to go immediately after, but with 3 strands this is less likely.

Post 296 for more info...
https://www.rcgroups.com/forums/show...anceled/page20

Post 280 for pictures of what can happen if you find yourself on the receiving end of a metal ring launched at you.

Interesting! I use a single line hi-start which when fully extended is probably some 700 - 800 ft in length. I've never worried about the anchored end hitting me because it just too far away. This is something different and I will have to explore it further as I am moving into larger 10 to 12 ft wingspan sailplanes. I've only tried a winch once and understandably, I was rather nervous about using it. It just so easy to overload a wing structure. this "Y" setup might be a good alternative.

Cheers!
Lyle

Another thought.....(yes, it can happen! : ) With this setup, if the wind shifts....which it inevitably does, you would have to either reset one stake or risk launching with the wind off at an angle. With the hi-start you have some latitude in that you can move your launch location left or right depending on the wind shift.

Regards,
Lyle

This hi-start is about 10 feet of rubber and 200 feet of line. You don't need a big field, but it's designed to create a LOT of tension, therefore the extra safety features such as no metal rings and the redundancy of 2 stakes and 3 strands of rubber.

Joe Wurts posted a couple of photos of his that uses 4 strands of rubber for even more power.
https://www.rcgroups.com/forums/show...&postcount=304

4 strands of the silver?

I have a traditional high start setup with 100 ft of the silver rubber and it will launch with pretty good authority. I have launched 85oz airplanes with no problem.

So this discussion came about because I built a zip start with rubber left over after re-working my primary high-start after it failed. The zip-start failed. Post 280 is my back after the line between the anchor and the rubber broke.

My original highstart had a large amount of rubber, purchased from GravesRC.com as a kit, and broke from age. This original break was a non-issue because the length of mono on the end. I took the left over, which was too short to provide the power to launch my 4m Xplorer at a good tension and turned it into a parallel setup similar to above. To make equal lengths of rubber I had ~2m left over.

I took the left over, which had one of the plastic plugs and metal eyelets for connection, and made a small zip-start. The difference being that it wouldn't be for full launches, max 10 steps, get me to approximate landing pattern height, for launch, land, launch, land, repeat practice. I used winch line to tie from a concrete spike to a the remaining plug and then added 7m of mono on the other end of the rubber.

Anyhow, I like the multiple rubber idea as it does make it safer.

At what length does a Hi-Start become a catapult/zip-start? just curious. I've used hi-starts since the late 1970's, had hi-starts let go on me (lost count) and never had to worry, the rubber looses energy in the first 50', never had a use for a short 30' - 40' catapult/zip-start.

Cheers,

Dave

Originally Posted by iflylilplanes

At what length does a Hi-Start become a catapult/zip-start? just curious. I've used hi-starts since the late 1970's, had hi-starts let go on me (lost count) and never had to worry, the rubber looses energy in the first 50', never had a use for a short 30' - 40' catapult/zip-start.

Cheers,

Dave

Not sure. I called my contraption by that name because it just felt like it was correct. The idea behind my zip start was not to launch a model to a height to hunt of thermals but to get it it to approximately the same height I'd be going downwind for the landing pattern. Some people just throw their model for landing practice. I found that I was spending more time working on setting up the approach from a sub-optimal throw than actually getting the model lined up as it would look like in a "real" landing.

Ok, I've always hand launched for landing practice, even managed a 25 minute flight from a hand launch once with a own design 12' floater (never had a name) just bounced of little puffs of lift till it gained a 150' altitude then went hunting for bigger and better thermals.

Thanks,

Dave

https://www.walmart.com/ip/Pet-Champ...Stake/20369862


Something like this is much safer as an anchor. It has way more grip on the ground, the tube can rotate around the shaft without fear of it pulling off a free end. Different sizes are available and you don’t need a hammer. Plus, they stick up a little which helps keep your rubber from fouling. I always put a small bit of bright covered ribbon on mine. Shows wind direction easily and limits people walking into it. Doesn’t stop them...

I like the idea of a very powerful small launcher. It’s hand for launch n spot land practice, or for hunting thermals at low levels which is a good skill to have. I made a similar unit but with very lite theraband for dlg launch. I’d call it more a catapult in my usage though. For me it provides horizontal speed which I translate to vertical like a dlg launch, but without and knee or back stress.