larry11

My Feedback: (6)

Baldeagle and siclic33,

Thanks for quickly answering my posted questions.

I had a successful maiden earlier yesterday.

I ended up bending my own landing gear out of thicker piano wire, and put on larger wheels.

I measured my reflex after landing and I ended up with 13.5 mm reflex due to my forward cg.

Larry

larry11

My Feedback: (6)

Landing tips needed.

Hey guys,
I had a chance to get a few more flights in and on the landings I was experiencing the dreaded kangaroo hop.
Any landing suggestions with this model to help eliminate it?

I do have a slightly larger front wheel to give it a positive aoa, and it is nose heavy when landing.

BaldEagel

The normal reason for the kangaroo hop is landing to fast, do you have the rudders set as air-brakes? if not then set them up to both go outwards the maximum you can get and see how you get on.

Mike

larry11

My Feedback: (6)

Yes,
I am using the rudders as air brakes.
Also, before touching down I am giving elevator input to try to flair it a bit.
It looks like a greased landing until it pops back up and down a couple times.

BaldEagel

Mine comes in at a very high angle of attack and never pops back into the air despite the rough ground I fly from, I can only think your forward C of G is causing you to land with to high a ground speed, therefore the wing is still producing lift when the nose wheel hits the ground and up she pops from the bounce off the nose leg.

Mike

EDIT: As I have said already mine is tail heavy with no fuel on board, so I have no idea how you got yours nose heavy?

BaldEagel

Larry

I have just been looking through my notes on the Ducty and it seems I packed up the exhaust cone end of the turbine by 1.5mm to get a higher angle of flair on landing, now I remember back it was difficult to get into a high alpha position to slow it down sufficiently for a short landing, it just ran out of elevator on the landing approach.

Mike

larry11

My Feedback: (6)

What did you do to the exhaust cone?

siclick33

You need to be landing as slow as possible to avoid the bounce. I'm not sure if you've flown deltas much but they don't land like normal models. If you're not holding a lot (almost all) of up elevator on touchdown then you're not slow enough. The Ducty will float on forever and if you try and force it down early it won't like it.

BaldEagel

Larry read the post again, I packed up the exhaust cone end of the turbine, not the exhaust cone.

Mike

larry11

My Feedback: (6)

Actually, I don't have a whole lot of stick time flying deltas. When I was landing I probably had it flared around 1/2-2/3 amount of elevator available. I was just afraid of stalling it if I flared any more.

Also, some other observations of mine when flying is when turning or banking at low to medium throttle it really likes to slow down and lose altitude. Is this normal with deltas? And, does it stall easily and typically what happens in a stall with deltas?

Larry

larry11

My Feedback: (6)

Gotcha, so you shimmed up the rear of the turbine, closest to trailing edge of wing.

So with slightly more up thrust, should it help or hinder in taking off as well?

Larry

BaldEagel

It will try to push the TE down, hence the LE up and the takeoff should be quicker, also the landings should be slower as you will be able to hold the nose higher, obviously this is a bit of a compromise and you can't just keep shimming up the turbine indefinitely, you have to find the happy medium between takeoff and landings and how it behaves in the air.

Dropping its nose in a slow speed turn is normal for nearly all turbine airframes, the use of up elevator in the turn does help, plus Deltas are very forgiving in the stall, generally they will just mush and loose height, try it up high and you will see what I mean.

Mike

p1andy

Hello all, 

siclick33

I have standard sized servos on elevons and minis on the rudders.

I think I velcro'd my fuel tank in place. The straps are just velcro straps that are bolted (with penny repair washers to stop them tearing) on to the metal stand offs that are in the kit. I didn't bother with a battery tray; I use a small (1100mAh) A123 for the RX, tie-wrapped to the main frame and the turbine lipo is just stuffed into the nose.

There aren't a lot of build tips to pass on as there's not much to it

BaldEagel

Have a look at post 67 page 3 and post 77 page 4 to see how I did mine, HS85MG on the rudders and HS5625's on the elevons.

Mike

r 3

p1andy
home Thur give us a ring or come round to the house. Do you want me to maiden it for u Ha Ha

p1andy

R3 I did send you a PM on AAMFC which was duly ignored hahaha. Yeah if I'm still home Friday I will pop out and have a look.

siclick33

I wouldn't use anything that small. Whether they would work or not, I'm not sure, but the Ducty doesn't notice a little bit of extra weight so I'd go for something a bit bigger. I can't remember exactly what I have but think they may be SH-1251MG.

BaldEagel

Why would you want to put mini servo's on the main control surface????? Use a good quality digital servo, you know it makes sense.

Mike

larry11

My Feedback: (6)

I was just reviewing the servos people are using for the elevons.
I have Hs-5245mg servos that I'm running at 6.0 volts. They have 76.4 oz torque.
Is this a powerful enough servo for this model?
Larry

p1andy

BE that's why I was asking what others were using.

BaldEagel

.

pyropupx36

Hello, I realize that this is an old thread, but I am just starting to assemble a new Ducty 20 for a P20, and it would help me to get started if someone could please tell me what height to make the engine bearers shown in many of the "Jetty's" in this thread. I want to make sure I elevate the engine sufficiently off the surface to preclude heating issues.

Thanks very much !
Gary

BaldEagel

From the U/S of the TE to the top of the mount mine is 60mm, sorry for not replying earlier, no excuse.

Mike

pyropupx36

Thanks very much Mike. I will post pictures of my build on this thread as well. Any other tips from those who have built "Jettys" always appreciated.

Gary