OzMo

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Hi Gang,
I was asked to post details of the Glider Launch Cradle. It is a hobby lobby glider cradle I found on FleaBa^. No longer offered I understand but they are not hard to make at all. About 2 degrees of down for the glider wing as opposed to the launch plane's wing. Slow to idle before release. These rods are drilled and tapped alum. rods but alum. Tubing with some allthread and lock nuts will work a treat. Two rubber bands on each side held permantly to the back and held by the "L" s on the front. The servo rods hold the "L"s until release time.
I added small blocks of wood so the release rods are kept in place and some stiffening of the upright parts with CF tow. It is intended to be held on with the wing by rubber bands. Other methods are common. I epoxied two pieces of music wire to the spar /ribs with fiberglass before sheeting the wing they are bent 90 degrees forward to hold the front alum rod. the back alum rod is held by a formed piece of gutter pipe (pvc) and folds over the back alum rod and is held by the wing bolts . Gutter pipe can be heated to moldable by a monokote heat gun.

dumorian

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Yeah and now guess what we want? We want a photo with a glider loaded onto it!

That really is a neat device. I would have thought it would have had the same wing angle but I guess the Telemaster wing needs to have full control so a bit of down keeps the glider wing from possibly steering the Telemaster very much or creating a big difference in pitch control? Very interesting.

Now, who's going to build a 747 or whatever it is with the space shuttle on the back?

Tinkrerpilot

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OzMo

Great job!! looks real good. Nice finish job too.
But I have to agree with dumorian it needs a glider sitting in the cradle.
So, how soon are you going to try this contraption out?
Will be looking for a flight report now............
Good luck and have FUN!!!

TINK

iflytailies

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it has been done, see here:

http://www.rcmovie.de/video/d2167a2f...-Space-Shuttle

jbrandon

Here is a link ([link]http://www.kssclub.org/activities.html[/link]) to some pictures of the Sun Chasers in Kansas City who utilize the tug system for launching sailplanes at their power field. It is primarily a power club but the month of March they proclaimed each Saturday’s as glider day. Our sailplane club Kansas Soaring Society ([link]http://www.kssclub.org[/link])was invited to share sailplanes with the Sun Chasers. March weather can be iffy at best so we only got a couple of Saturdays of flying in.

They have two or three qualified tug pilots and the tug was more than capable of lifting my Starlight 3000 to just about any altitude I wanted. For those who do not know the Starlight is 130� wing span weighing in at 74 oz ready to fly. The tug pilot asks me to hold about half down during the climb out. Transition from power to sail is smooth as the tug pilot will reduce power and release allowing the sailplane to just fly straight on while he turns and dives away.

The only draw back to the system is the rubber bands holding the sailplane wrap across the flap and will cause a buzzing of the servos. And at least on the Starlight there is no room at the root for the bands as the cradle is about 6� wide. I found if I cambered about 2 deg the buzzing stopped. Later in the day the tug pilot learned if he stretched the bands across the leading edge the buzzing was not a problem.

Not a bad solution for somewhere where winches can be a hazard to string out and have the line float back over the runway. Only problem is someone is always on the ground looking longingly up at the soaring sailplanes.

OzMo

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BOY!
This is a tough room! Yeah, I can't wait to try it out. I need to get very comfortable flying the Telemonster before I put a glider on it. It should be well dialed in, it needs a little more elevator authority.

iflytailies

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we were piggy-backing an EZ with the TM, the pilot then did some aerobatics

http://www.youtube.com/watch?v=FRUAF2kG28k

sjgoulet

Hey Oz, bring up the telemonster im headed to the club field this afternoon. Ive got 2 you can take picts of so everyone can see a glider on your bird. We will be there around 4:00pm its located off of Hwy 13 and U road. Actually call me and ill give you directions if ya want to come out and play.

See ya Steve

colmo-RCU

This is my version

ALWAYS REMEMBER TO CHECK BOTH PLANES RADIOS

colmo-RCU

some more

Tinkrerpilot

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colmo-RCU

Is that a Goldberg Tiger .60 you guys are using for a tug? Very nice! Any problems when flying or anything out of the usual when you are carrying a glider aloft with it? Would you give us some details about the plane. Looks like it is up to the job of glider launching.

tink

colmo-RCU

hehe, it's a tiger 40, actually. It has a Saito 60 twin which weighs twice as a 2 stroke 40 and has less power. We fly at 8300 ft (Bogota). The plane has a hard time getting up to speed with the glider on it, but it gets a lot of extra lift from it. It takes off well before stall speed for the plane alone, climbs slowly but steadily to whatever height you can see it, and then you just throttle down and release. The tiger drops instantly out of the way of the Spirit. I used 0 deg for the base but I'll use -3 or -4 for the next one as the glider has to be with full down elevator all the time or they will climb to a stall. We fly near the base of a mountain range where people fly hangglider and parafoil, so I get 1 hour flight off the sailplane easily. The only thing is that thermal gliding at this altitude is impossibly. Air is just too thin.

The reason I used this plane is that my other one is a goldberg extra and I was not about to risk that one with the glider. But I would prefer something with a little more lift of its own and a lot more power. This one is pretty IMO but not ideal. Also, a low wing tug requires a higher base, with the added problems of flexion (did I say it right) and structural integrity. But on the end it does the job and looks cool

Tinkrerpilot

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colmo-RCU

Very nice. Thanks for the details. Hace you guys thought of going to a Sr. Telemaster or something along that line? Would make a great difference. The Sr. Tele has a lifting wing with a Lifting stab that would help in most cases. There are some good reviews for the plane and what the guys are using in the motor department. A few of them are even electric powered that should work well to. Just some other ideas to throw out there. Great job!

tink

vicman

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Here is the one we did. The glider is a Sig Samurai and the tug is...well it's a club trainer of some sort. Take off was ok we also had to be cautious of stalling but didn't need to make any corrections in flight with the glider. The tug pilot just needed to be cautious. The wire landing gear was a bit frail.

colmo-RCU

Yeah, a friend is finishing a .60 Protege (a somewhat aerobatic trainer) with an OS 75 2stroke. I think we'll start using that. Also, I think we'll use it to tow my 4 meter ventus. We'll see

lordmerren

Tink

Back some time ago (page 6 on this forum) I posted a thread, showing my old tug and cradle which had become lost, and I was looking for help at that time, to find info to build a new cradle. I received lots of help (thank you everyone), and I proceeded to build, promising to show you the end product after it was sucessfull. Well today I gave my new tug, a Kadet Senior, along with my home built cradle, and my sixteen year old Sophisciated Lady it's maiden flight, and all went well. I climbed to a couple hunderd feet and released the glider, landed the Kadet right away so I could watch my buddy fly my glider around for a while. All the guys at my club now want gliders. The glider has had many flights on my high start, so it was only a maiden flight for the Kadet.
Here are some pics if I do it right.

Tinkrerpilot

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lordmerren

Great pics. Thanks for postuiing them. Now it sounds liike you are going to have your hands full hiking up the other club members gliders for them. Great fun to be had with this set up. Awesome job on the Kadet Senior. Always good to see the older gliders still hanging in there after so many years.

The rest of the story is I guess is that there has been some great talk and help here to get some of the guys to a point that it makes the hobby more enjoyable and to draw others into the same fun that we all can share in.

For those that have posted pics here, great job. Keeping them coming. So are we ready for aerotowing yet???

tink

echostud

So when you're taking the tug/glider combo aloft, do you try to climb like a rocket immediately after takeoff, or do you circle in a more gentle climb to gain altitude? I have a Kadet Sr with a ST 75 on it so have plenty of power to do it either way. We tried aerotowing and the towplane/release setup worked well, but man it was tough to keep the glider behind the towplane in turns. How many rubber bands do you use to attach a 2 meter glider to the cradle?-if it's more than a couple (which I've found doesn't work too well) is there a problem with the release rod binding up?

A10FLYR

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I climb at the max angle that will keep the towed glider flying....not hanging! I've managed to climb very steep with the glider hanging and slowly push over the top but I don't consider it to be very safe! Much better to go at less of an angle, in my case about 45° and a large gentle turn. My tug is a homebuilt fuse with a Kadet Sr wing and an OS 108. I've taken 2 100" gliders up at the same time using the cradle and tow line.

The glider pilot only needs to keep the wings level. The glider WILL follow the tug!

I use 3 bands on each side to hold the glider down. Remember, you don't need or want to go fast! Also, angle of attack on the glider wing in relation to the tug wing is somewhat critical...experiment. I find that with a glider in the cradle the combination wants to climb excessively so I've programmed extra elevator trim into the slider on the left side of the transmitter so that I can make large trim adjustments depending on the different drag/lift combos without changing the trim when I'm flying the tug by itself.

OzMo

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On rcgroups, in the scale sailplane forums, you can see some video of scale towing. I would call the angle of climb "moderate". I would also think you would want to keep the glider above the tug all the way up. But then I have not yet tried this. I think I will fabricate a simple tow dolly though.

colmo-RCU

Dean, you placed the servo with its widest part facing forward. I know you have plenty of power, but why not fight for less drag?

OzMo

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Tryed out the piggy back cradle today. Sorry no pics. We had our Club's annual spring fun fly todayI had the cradle on the Telemonster. Second time out to fly it. One of the guys had hisGentle Lady and said lets try it. We checked to make sure it released then we just went for it. Had to hold some down elevator in the climb out and it was more sensative to the mild cross wind but handled fine. We released at around 200 feet so we could obseve well. Thats when Iran out of gas so we both glided down. All in all a very good day

OzMo

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Tryed out the piggy back cradle today. Sorry no pics. We had our Club's annual spring fun fly todayI had the cradle on the Telemonster. Second time out to fly it. One of the guys had hisGentle Lady and said lets try it. We checked to make sure it released then we just went for it. Had to hold some down elevator in the climb out and it was more sensative to the mild cross wind but handled fine. We released at around 200 feet so we could obseve well. Thats when Iran out of gas so we both glided down. All in all a very good day

snuts

I use an electric assit glider to carry my Fling up. Then my friend flys it down. Yesterday he flew for 25 min over the rural intersection 1/4 mile down the road. I managed to start in the same thermal and ride it to a new recorded "high" of 3499ft. That was at 6:30pm. No mods to the Fling, built the 3meter with a release, using no stretch fishing line.

gshort72

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Lordmerren,

I was thinking of doing a kadet senior for this project. What size engine are you using and is it enough power, not enough, more than enough?

Thanks
Greg