jeffp2000

Greetings all,
I am looking for some kind of one man or easily operated sailplane launch system for open class comp. sailplanes I am in a remote location and usually fly alone or have the wife help me. Hi Starts arent powerfull enough every catapult ive seen is either too small or too violent I would like a electric winch and automatic retriver (if there is such a thing) I saw a hands off retriver but I would rather spend $700 on a new sailplane. I am looking for a kit or plans There used to be a old "swing arm " retriver that used a windshield wiper motor to level wind the drum during retriveing but I havent seen one since the 90's one prospect that looked promising was a hi start that you anchored at your feet and then went out through a turn around and came bach to the plane I envisioned using this with a release mechinisim from a catapult (bungy) launcher that I could operate with a foot pedal any way I would like to hear from the sailplane community on this
Thanks, Jeff

Buran

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Northeast Sailplanes sales a Pinacle Heavy Duty hi start for 4-m plus sailplanes. It cost a little more tha $100.00 and works fine. You need lots of space though. I launch my Simprop Solution XL (4-m) with no problems. I think I get a little more height than the club winches.

jeffp2000

Thanks for the reply I think with this histart my Idea about using a turn around could work. I saw it in a british r/c forum sometime ago they put rhe turnaround in such a place so when the line was fully pulled back that end of the leader line (and the end of the rubber ) was just before the pully so you have the same total length of the high start but with half the setup length and due to the use of a pully (the turn around) and a fulcrum (the anchor point) you should gain a mechinical advantage and get a better launch (in theory) Am I nuts or what ?? I would like to improve this with the addition of a launch ramp like a catapult launcher with a remote release

Chocks

Go to www.superskegs.com he has a great winch that would fit your style and budget. I am in the process of copying this winch for myself. I have access to a complete CNC machine shop. I am just having trouble finding the time right now. Check it out and let me know what you think.

Chocks

Correction for my last reply. The web address is www.superskeg.com

BMatthews

With just a single turnaround pulley you don't get any mechanical advantage. It just reverses the direction of the pull. YOu also still need to put the turnaround about 400 to 500 feet upwind or your launch height will be limited to the distance from the launch point to the turnaround less whatever amount of line is pulled back by the rubber. So for a 500 foot final launch you would probably need the turnaround upwind about 600 to 650 feet depending on how far the rubber stretches for full power. But that means the rubber and some of the line is constantly rubbing on the ground. This will add drag and also may hard the rubber depending on the ground surface. And you still need to go and fetch the end and pull it back in any event. So I say keep it simple and just lay the high start out normally. A 4 meter model will easily lift the rubber up off the ground anyway so you get some extra height.

Depending on how many launches you do what's wrong with using a simple winch and shagging your own chute? Provided there's some lift you may only put in 3 or 4 longer flights over the course of an afternoon. If it's less lift than that you'll probably only do maybe 5 or 6 flights and then go home anyway. That isn't that much chute retrieving is it? You'll same a heap of money, weight and setup time compared to a retrieval system and shave off that tummy at the same time! A buddy of mine has a simple winch of this sort and I've flown with him often. It's not that big a deal to fetch the line really. Only in a contest situation with a lineup is the retriever a neccessity.

jeffp2000

you have a point I was just trying for a compact powerfull launch system multiplex used to make a bunge launch system but I dont think its around any more

jeffp2000

I found the site I found the modded highstart at [link=http://home.clara.net/barcs/barcs-nf/easimoore-launch.htm]launch system[/link]

BMatthews

Yep. That only reverses direction. It does not alter the pull at all.

Liberator

My Brother and I have been experimenting with this as much as the winter in Utah will allow. Let me tell you the readers digest version of what we found out.

We started with the Dynaflite Heavy Duty High Start for the 2 meter planes we were building/flying. THis worked great but the ever larger stuff calls. So we purchased from Hobby Lobby the "orange" rubber which is the middle strength for 2 and 3 meter.
We also set up a very quick turn around system that actually clipped to a fence using a C clamp and a climbing pulley we bought from REI for about $12.00. This setup works ok, however BMathews is right on the money about the friction of the rubber on grass, or whatever the surface is that your flying from.

We have thought of using a series of bicycle wheel hubs set up along the ground for the rubber to "ride" on as it is pulled tight, but this is expensive to get going as well as a pain the the rear to set up. The theory for the turn around is sound. Lifting the rubber off the ground uses energy that would be better imparted to the plane via just hauling the line up which is a lot lighter. But with out someone either pulling the rubber along the line freeing it from the ground grabbing it, or a device that suspends it from the ground, the launches are lacking in altitude.

So for giggles we just clipped the line back from about 1000 feet to about 450 feet and just did as BMathews suggested and ran it straight from the stake to the glider leaving the turn around out of the mix.

Bottom line the launch is higher, quicker, with more power by far than with the turn around. Plus, set up is quicker which leaves more time for flying than setting up.

Keep it simple, don't re-invent the wheel (or the high start) and have fun.

Also I am launching a Thermic 2.5 meter and my Bird of Time with this and it is working like a champ. This rubber is super tough and strong and will handle a 4 meter plane with no problem.

Tom

SoCal GliderGuider

Use a simple electric winch and run the parachute down to close to the turn around. Yes you will have to walk but it keeps the parachute and line from drifting cross wind and into obsticals.

You can make a winch drum with off the shelf hardware including the v-belt pulley. Core is a rolling pin. Sides can be masonite. Base and motor mounting can be heavy plywood.