Scale Towline Gliders

[bcarter1234]

Is there any interest in a discussion of scale towline gliders? I just built my first about two weeks ago, a 36" wingspan Reiher. I'm still learning a lot about towing and trimming but at least my homemade tow reel is getting a good shakedown.

This 36" Bowlus Baby Albatross is foam construction. The initial test glides showed promise, the first tow started well but ended in tears. I'm hoping the new larger vertical stabilizer will sort it.


 

[TheLurker]

Interest?  Yes, definitely and if you're looking for more FF bungee/towline scale subjects I've just stuck a small handful, indoor & out, in the plan gallery. 

[Stunthenk]

How do you get a bungee launched glider to release from the line? I tried a few years back, outdoors with an Aiglet, but it simply rode the line back to the ground.

[g_kandylakis]

vertically down? I would like to see that... 

[Lastwoodsman]

Towline gliders are fun.

    I had some great success with a  20"  Osprey towline glider from Vintage Model Co.    It is not easy to get a model to release from the tow line, instead of "kiting" into the ground,  but once you do,  it is like "bringing in the herd".   
I would suggest opening the tow hook wire opening a little bit more.

And there is always this trophy to aspire to ...

Pic #1    7015  High Start Towline Glider Trophy

I'm no expert - I am only one for two on gliders ...

Lastwoodsman
Richard

[Squirrelnet]

The Baby Albatross looks great bcarter, as Lurk say's says yes lot's of interest in scale gliders

How do you get a bungee launched glider to release from the line? I tried a few years back, outdoors with an Aiglet, but it simply rode the line back to the ground.

Sounds like the hook position was too far forward, the position is used to trim the tow/bungee stage with forward and back to govern the release point and side to side to give turn on the line. Sounds counterintuitive but you can then set the model to fly in a circuit and use an offset tow hook to induce a turn opposite to the glide turn so it stays straight on the line without an auto rudder.


I find Scale Gliders on a bungee very addictive. I've done a couple, which had builds on the old HPA, Lurks lovely Airspeed Tern (plan in the plans gallery) and an OD Slingsby Eagle.

vertically down? I would like to see that...

It's shame you are not around in the Uk around the OMFC scale glider comp...there's a lot of that there...usually from me 


Here's a pic from the summer with HPA members having fun with the bungee

[Stunthenk]

The Baby Albatross looks great bcarter, as Lurk say's says yes lot's of interest in scale gliders

How do you get a bungee launched glider to release from the line? I tried a few years back, outdoors with an Aiglet, but it simply rode the line back to the ground.

Sounds like the hook position was too far forward, the position is used to trim the tow/bungee stage with forward and back to govern the release point and side to side to give turn on the line. Sounds counterintuitive but you can then set the model to fly in a circuit and use an offset tow hook to induce a turn opposite to the glide turn so it stays straight on the line without an auto rudder.


I find Scale Gliders on a bungee very addictive. I've done a couple, which had builds on the old HPA, Lurks lovely Airspeed Tern (plan in the plans gallery) and an OD Slingsby Eagle.

vertically down? I would like to see that...

It's shame you are not around in the Uk around the OMFC scale glider comp...there's a lot of that there...usually from me 


Here's a pic from the summer with HPA members having fun with the bungee

Sounds logical. The hook position I used on the Aiglet was the same as I used with a normal tow. Doesn't an aft hook position cause exessive pitch up? And how  much further aft should the hook be?

[Squirrelnet]

I think the angle of the hook relative to the model centre line has an effect on release as well so it may well be the hook position is right if it tows ok by hand . Opening out the hook will allow the model to release earlier and not get stuck on the line. If it pings off too early then close the hook up a little

[bcarter1234]

Conditions here this morning were lovely so I took the Baby Albatross out for a few low altitude tows. It flies great and shows a lot of promise. I've still a lot to learn about trimming for best performance. My best flight this morning was about 15 seconds from a 30' launch. At this point it tracks well on tow and flies mostly straight. I'm in a restricted area so I'll begin working on trimming for a decent circle then go for more altitude.

Here is a picture of the tow reel. It gives 80" of retrieval per turn so the cranking is pretty relaxed. A hole in the handle allows it to be staked to the ground to pull the line back out as the glider is carried to the launch point. The gift card keeps the line from coming off the reel and getting tangled.

[bcarter1234]

Video of one the of the flights of the Baby Albatross this morning. Towing then filming is proving not to be my super power.   

[bcarter1234]

Interest?  Yes, definitely and if you're looking for more FF bungee/towline scale subjects I've just stuck a small handful, indoor & out, in the plan gallery.

Thanks for posting those. I'll go take a look.

[gravitywell]

bcarter1234    Dude!  You have got to publish a plan of some sort for that winder!  It looks amazing.

[bcarter1234]

bcarter1234    Dude!  You have got to publish a plan of some sort for that winder!  It looks amazing.

The handle, crank, reel center and large pulley are all cut from 1/2" plywood. The pivots are 1/4" bolts with bronze bushings from the local hardware store. The large pulley is 4.5" diameter, the reel center is 3.75", the reel flanges 5". The main body is 1.5" x 16". The crank is 1" x 5.75" and extends 4" from the center of rotation.

The small pulley needs to be small. In retrospect a spacer between two nuts might work well for this application.   

[bcarter1234]

Fuselage for a sort of scale 36" Nemere showing the template used to hotwire cut the wing saddle. Rough shaping will be done with a Stanley Surform Shaver followed by drywall sanding screen then sandpaper. The drywall sanding screen was a game changer. It works fast, and isn't as prone to cause tear outs in the foam like sandpaper can.
 

 

[bcarter1234]

Wing cores rough cut to outline, ready for sanding. You can see the chord had been expanded significantly.