Glider Tug

[peason]

Hey guys, I've talked to a few of you guys about setting up a glider tug.  I've got a Tower Trainer 60 with an Axi 4130/16 motor on 6S that I'm rebuilding.  Converted it to dual ailerons and finishing up adding a tow hook with a servo release on it.  The plane's large (70" wingspan), has lots of power and should tow just fine.  The 4130/16 is a bit low on KV for 6S, but in the past it had plenty power to yank the 60 around just fine (kind of a what's on the shelf in Paul's shop kind of thing). 

I'll get it set up this weekend and make sure it's airworthy again.  I've got a couple Skysurfer (also known as Bixler) powered gliders that have good glide characteristics that might be good first tow candidates.  Red mentioned that he used a about 1" of Velcro in a lap joint for the glider hook-up.  When you get to altitude, if the glider pulls up as the tug goes down the Velcro will separate.  The servo tow hook (just behind the spar in the center of the plane) would let the tug release the glider if anything goes wrong. 

I'm looking for advice on the setup and would like to know if anybody is interested in giving the tug/glider combo a go.  Any idea on how to test the tow setup in flight?  Maybe drag a banner or streamer and drop it over the runway?  Ideas would be good...  I'm in LA through Wednesday but will post some pictures when I get back.  Paul

[peason]

Pretty sick with a stupid head cold so I doubt I'll make it out to fly this weekend.  Will pick things up in a week or so.

[Red]

Sorry to hear Paul. Looking forward to seeing this!

[peason]

Gave it a try today not a lot of grunt on take-off.  Used a 15x8 prop since the Axi has such a low Kv and had to raise the front gear up enough to clear...  well, not enough since I had a prop strike.  May try a 3 blade or look into using some CF gear that I have and convert to a tail dragger and use a 16x8 prop.  The thing is very heavy at 11lbs.  However, if I could get the motor propped right, the 4130/16 is equivalent to a 90 glow so it should be able to pull hard with the right prop.

I did find a 600Kv motor in the bin, but don't have any 5S batteries - will look at how well a 4S will do.  May try to lighten it up.

[peason]

Finally got a chance to mount the 600KV motor - Turnigy 50-55.  e-calc said that it'd pull 66A with a 6Cell batt and a 13x6 prop - only had a 13x8 and static it pulled about 90A!  Thats 10A over the rating for this motor and 20A over what I'd feel comfortable with a cheap motor.  Yikes!  However with a 100A ESC and good throttle management I should be fine.  Had tons of thrust for a blip of full throttle.  I should be good to go next weekend (not traveling unless the new grandbaby comes early). 

I have some glider release latches coming tomorrow from HK-USA and will fit them into my Bixler.  Any idea how long we should set up the tow line?  I plan on using some 100lb test ultra stranded fishing line that I use for big game fishing, should be plenty.  Hopefully I can have the whole setup done so with the help of another pilot we can try this out - something that I've always wanted to do.  Any takers?

[tall n skinny]

Sure I'd give it a try. What the hell it's all your equipment. I'll fly either one for ya. Let me know when. Julio and I tried this a few years ago up at the old field. We did OK considering e didn't know what we were doing and didn't have a proper release method. Sounds like you've got it together.
John

[tall n skinny]

I should have mentioned--I'm not working--just give me a call on my cel and I'll meet ya up there.
695-7353

[peason]

John,

I'm flying an electrified Tower Hobbies 60 trainer with an emergency release servo about 2" back from the CG on the top of the wing (this is the tow point):

http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXCAS1&P=8

For a test glider, I've got a Bixler powered glider kinda like this:

http://www.hobbyking.com/hobbyking/store/__19988__Hobbyking_Bixler_v1_1_EPO_1400mm_KIT_USA_Warehouse_.html

With a tow release on the nose:
http://www.hobbyking.com/hobbyking/store/__32011__HobbyKing_Glider_Nose_Tow_Line_Release_11_7x42mm_USA_Warehouse_.html

Both are 2.4GHz Spektrum setups.  Once I get my backup transmitter from Wiley (or Bill) Walters I should be good to go with a complete turn-key system.  I'm looking for a glider pilot with some experience, looks like I have a volunteer.

Got your last post John... I am working and in the time that it took to write this, I'm now going to Tucson for work this weekend and then to Florida and won't be back until the 11th... looks like this is on hold until mid month.  Hate the travel but at least it's good to have a job...

Paul

[tall n skinny]

Great-like I said-I'm not working, so just give me a call and I'll meet you up there. I know from experience that the glider pilot has to stay behind the tug and not get any higher then the tug. The last time Julio and I tried it, he (glider pilot) got way above me pulling my tail UP and therefore keeping my nose DOWN and we wound up down in the jungle, still tied together because of our "Mickey Mouse" release set up. Soooooooooooo-I didn't want to try it any more. But we did have s few succesfull flights. I'm sure you and I can pull it off without a hitch.
Anxiously waiting-John

[peason]

Good deal John,
We'll give it a go when I get back.  I'll give you a call.
Paul

[peason]

Before I left last week I did get a 13x6 Master Airscrew in and it calmed down the over current situation pretty well.  About 70A on the deck so it should be fine in the air (just under the motor's 80A limit).  Still wants to pull my arm of on the bench so it should have plenty of grunt to pull gliders.  Will give it a try in a couple weeks, for now I'm not sure if I'll be around on a weekend until the end of March.

[tall n skinny]

Paul-I can meet you during the week if that's doable for you. Or we can wait 'till a week-end.
John

[peason]

Hey John, I've been suck on the east coast most of the week and part of the weekend.  Won't be around on a weekend until the end of the month.  Work during the week, but we'll get this sorted out sometime soon.  Thanks for your patience.
Paul

[tall n skinny]

No problem Paul. Just give me a call the night before and I'll be there.
John

[peason]

This past Sunday, Wylie and I got a chance to try out the tug and the glider.  We had Paul K there to record some incriminating evidence!

Our first attempt was aborted when the tug took off and at about 10' off the runway and my prop started slipping.  Wylie was quick on the glider release and since it was powered just kept flying.  I ditched the tug (also released my line) and got the tug down just as the wing touched the grape vines on the south side of the runway.  Luckily, no damage at all. 

We tightened the prop and tried again.  With our 50' tow line and this time an easy hand on the throttle, the two leaped into the air with ease and before you know it they were both dots in the sky.  Wylie kept the glider up and to the right so it wouldn't cross the tug's tail all the way up (great job Wylie).  He hit the release and I landed.  I think I made some turns that were a bit tight, but thankfully Wylie is an ace pilot and he kept the glider in the right position the whole time.

Paul K took some pics and some video from my phone (thanks Paul K).  The video wouldn't upload, so I'll edit it and post in another reply.  Thanks all for making this happen.  Sorry John that we didn't get to try this out together as planned!  Maybe we'll give it a try one of these days.

Paul E