Tiny trainer derivative

bracesport

Legendary member
So, I made a wing for my DLG with the method of sanding the inner surfaces and glueing them together with gorilla glue (described above), but sadly the wing template was slightly wrong and it ended up under size.

So I decided to use it on the V Tail TT and build another one for my DLG with the updated template on that thread.

The main wing has been joined and cut down from 1.2m to 1.0m. I used a 13 deg dihedral template.

The dry fit looks not too bad so tomorrow I’ll glue it all together and look at the control surfaces.

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bracesport

Legendary member
@flyboa - The 1.0m V tail TT is taking shape while I rebuild the 1.2m DLG wing with the corrected chord - the throwing peg is in so I can try a discus launch and/or some sloping - I expect this to be about 200g with servos, battery and Rx - about the weight, should a sloper be heavier than a DLG, or put another way, can a DLG slope??
 
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bracesport

Legendary member
Fitted the elevator servo under the wing up the front of the TT - as it is a bank and yank setup, I made a Y tail assembly on the push rod to join both elevators to the one pushrod - seems to be OK!

Ran out of servos to finish the Ailerons!
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bracesport

Legendary member
There are a couple of parallels now between the V tail TT and my homage to flyboa’s DLG thread. I will attempt with both of them to DLG launch 🚀 and also have a crack at soaring.

These are not the first FBs with DLG qualities, but the TT is unique in that it is 100% FB.
 

bracesport

Legendary member
As I was running low on servos, I got a bit creative and Y linked the ailerons to one servo - it was a tad more complex than I imagined with fixed length pushrods, however, I got things close enough to be able to get the TT in the air - I have more than enough aileron movement that I can tone down with 'endpoint' adjustment in the Tx.

I also got some small 700mAh 3.7v lipos that can stack in a battery housing to give me 7.4v dropped through a BEC to 5v for the Rx and servos and this should be light enough of a setup for my 1.2m DLG build as well! The 1.2m DLG with have separate servos on the ailerons to enable differential and/or flaps.


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bracesport

Legendary member
It is a hard business to save weight without getting some more gear - with two small servos and pushrod wires the fuse weight crept up to 185g from 155g and the radio gear, BEC, and batteries add another 75g for an AUW of 260g.

All going well this time I can get a smaller Rx and battery to save more weight!

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bracesport

Legendary member
Today is a beautiful autumn day here in Wellington. Sadly it’s a Wednesday and I have to work! So no maiden today! 😫

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bracesport

Legendary member
@flyboa - looking hopeful for Saturday afternoon if the weather is accurate - DL(TT)G is ready to fly, and hopefully, I can get the other DLG finished (still need to hook up the pushrod for the tail)!

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bracesport

Legendary member
@flyboa - well, the weather was great - but it was not a good start with the DL(TT)G!

I should have done some more research - I think I am trying to launch it upwards rather than throwing at the horizon - but to be honest I just don't know - the TT just rolls over on launch?

Flies well with the straight hand launch

back on the bench - I discovered my tail was damaged on one side (fixed that) - the nose was heavy (so I shifted the battery under the wing) - I mixed in a launch mode that gives me a little up elevator - I am considering adding a second mix to the launch mode to give it a bit of right bias?

Any input welcomed!

 

Paracodespoder

Elite member
@bracesport , from my experience that roll you’re experiencing is caused by trying to discus launch a v-tail, it doesn’t work too well. I’ve tried a couple different times to build a DL v-tail, always ending the way yours did (I also tried dl-ing a side arm launch balsa glider that was a v-tail, same result). I was hoping that it was just me and yours would work, but it looks like v-tails won’t work discus launched :cautious:. Try it with a normal tail, it might work a little better, good luck.
 

Hai-Lee

Old and Bold RC PILOT
From the video it appeared that the release was not good for a plane with such a distributed mass as the TT type. It has a relatively short tail boom and so the tail surfaces have less effect at slow speed.The distributed mass is such that the mass of the outer wing and its inertia cause the outer wing to "Try" to maintain its velocity whereas the inboard wing due to its mass and inertia "Try" to maintain the velocity of the inboard wing. It is this difference in relative velocities that is causing problems.

Try to ensure that the inboard wing is pushed in the direction of release at release. If you do not manage to accelerate the inboard wing to the same velocity as the outboard wing at release the wing travelling fastest will generate the greatest lift and so a roll or turn will ensue. The greater the distribution of mass the more accurate your release will need to be!

Just from my experience!

Have fun!
 

bracesport

Legendary member
@Hai-Lee @flyboa - thanks for the replies - what you both say makes perfect sense.

I could see in my video the launch was bad and I’m confident the C/G was off - the tail was probably damaged in one of the launches.

The good news is I’m not giving up just yet!

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