Five Years of Evolution

[Jurgen Heilig]

Using Martin Müller's competition models, you can see the development of Indoor Aerobatics over the last five years:

[Andycap]

I assume aircraft no.6 usesa mylar baloon type envelope from what i see in the picture, it would be interesting to see just how much weight this concept saved. My guess is just a few grammes, revolutionary all the same. Also like the new machine with the fixed dive brakes

[Trisquire]

........ it would be interesting to see just how much weight this concept saved...........
It may have been an alternate way of creating drag as well; for constant speed flight.

Tom

[CharM]

In the latest model what are the little cutouts along the trailing edges for? Also is that a VPP set-up?
:D

[Bsouthwell]

I just picked up on the pull pull on the ailerons (Manta)......nice!

Bill

[Jurgen Heilig]

In the latest model what are the little cutouts along the trailing edges for? Also is that a VPP set-up?
:D

The little holes in the trailing edges are "Top Secret". ;)

No VPP in this model - just a standard MicroRex 220-3 (11g) motor.

:) Jürgen

[Trisquire]

I just picked up on the pull pull on the ailerons (Manta)......nice!

Bill
It looks like they run around a pulley.

[Team3D]

Hey Jurgen,

Can you give us some info on this model on how it is built and also the
measurements of it

[Draganfly]

Tris, thanks for pointing that out. I was looking at the pics and thinking those don't look like arms, but I didn't realize they were round pulleys.
-Adam

[Trisquire]

Draganfly,

There is a continuous cable that runs across the top of the wing from one pulley to the other. There is a little cutout in the fuselage to let it run through. I suspect it's the same underneath the wing, only the cable attaches to the servo.

Tom

[Jurgen Heilig]

Hey Jurgen,

Can you give us some info on this model on how it is built and also the
measurements of it

You are really interested in the old stuff?

http://www.rcgroups.com/gallery/showphoto.php?photo=15919&sort=1&cat=500&page=4

http://www.rcgroups.com/gallery/showphoto.php?photo=15894&sort=1&cat=500&page=7

http://static.rcgroups.com/gallery/data/506/1636Martin-A.asf

:) Jürgen

[David Kyjovsky]

Well Martin will be always in my mind as the "great inovator" :)

[Trisquire]

It seems to me you've done a bit of innovating yourself David.

Regards,
Tom

[Bsouthwell]

I have a new design going together as we speak....I have it set up for pull-pull on the tail but seeing the aileron system above it might be worth trying.....lighter and tighter! LOL I just need to see about fabing the pulleys. I have some phenolic and PCB material.....hmmmmm. I have a 18 gram motor built for it, every gram saved will help.


Bill

[Jeff Pfeifer]

Here is the pull-pull aileron setup.

[Draganfly]

Jeff, what method do you use to adjust tension on that aileron pull-pull?
Jurgen, what method does Martin use?

[Malves]

Here is the pull-pull aileron setup.

Thanx for sharing, bro.:)

[sairaghi]

The little holes in the trailing edges are "Top Secret". ;)

:) Jürgen

Why starting a thread "five years of evolution" and than say "this is Top Secrect"? :confused:

[perttime]

Psychology...
When a "champion" shows up with something new, everybody else thinks that they have inferior equipment... Then he says it is top secret and nobody else can concentrate on flying :)

[Jurgen Heilig]

Why starting a thread "five years of evolution" and than say "this is Top Secrect"? :confused:

Why do you think I added the ;) Smilie?

I already posted a close-up shot here:

http://www.rcgroups.com/forums/showpost.php?p=5124647&postcount=2225

There is also some discussion about the purpose of the holes in this thread. ;)

:) Jürgen

[perttime]

All the pros are required to run them now.. kinda like restrictor plates in NASCAR!! :D :D :D

I bet she put them there to start long discussions like this about them LOL! :D :D :D...

[sairaghi]

Why do you think I added the ;) Smilie?

I already posted a close-up shot here:

http://www.rcgroups.com/forums/showpost.php?p=5124647&postcount=2225

There is also some discussion about the purpose of the holes in this thread. ;)

:) Jürgen
now all becomes clear! :)

[CharM]

What works best for the pull-pull line? I've been trying different types of "Spyderwire" and it all stretches and ends up with lots of slack. I'm going to make a sorta Manta based on the pictures , maybe even with the secret holes in the trailing edges.

:D

[Trisquire]

Don't leave out the canted SFGs. :D

Tom

[Erik Johansson]

What works best for the pull-pull line? I've been trying different types of "Spyderwire" and it all stretches and ends up with lots of slack. I'm going to make a sorta Manta based on the pictures , maybe even with the secret holes in the trailing edges.

:D

I bought a roll of Berkley Fireline (the thinnest one available is the one you want). It is said to work really well.

/Erik

[Andycap]

If they are acting as sfg's there pretty small and a long way aft of the cg. More like dive brakes to my way of thinking . Pssst perhaps we should add some holes to them too.

[Larry3215]

What works best for the pull-pull line? I've been trying different types of "Spyderwire" and it all stretches and ends up with lots of slack. I'm going to make a sorta Manta based on the pictures , maybe even with the secret holes in the trailing edges.

:D


Part of the problem is the foam itself expands and contracts with temp changes. You build in a nice indoor temp, then go outside and the entire plane shrinks or expands. For indoor models its not such a big deal, but its still a factor. Some of the indoor places I have flown have been relatively chilly compared to my workshop.

Larry

[mikemann]

Hate to sound stupid....but Is it just me or am I the only one who read the above thread and did not get an answer or even a clue on the holes and canted SFG's? :-)

[Erik Johansson]

Hate to sound stupid....but Is it just me or am I the only one who read the above thread and did not get an answer or even a clue on the holes and canted SFG's? :-)

Two words: downline braking! :)

Both the holes and the fins are ways to create additional drag.

/Erik

[Devin McGRath]

for pull pull I found the best thing to use is fishing line. I use low stretch 17 lb test. you want some strech but not a lot.


Devin McGrath
www.devinrocks.com

[TRuss]

I'm trying to figure out the pull pull ailerons. Are there pulleys on the top and underside of the wing. It looks like the servo is mounted laterally, with half of the servo arm on the underside of the wing and the other half of the servo arm located on the top part of the wing.

If anyone can make any sense of what I just typed...then can you tell me if I'm on the right track here?

How tricky would this system be on a bipe?

[KNUFFAN]

You are on the right track! It would be the same on a bipe if you wanted it to be..The second set of ailerons is driven by the first set.

[TRuss]

Great! I was a little perplexed at first, but now it doesn't seem too bad. I think I might try it on my next plane. Thanks.

[Trisquire]

Post removed.

[Jurgen Heilig]

Those guys who watched closely the models used in Carvin in November 2005, would have been able to spot the Manta prototype:

[WACOFlyer]

What are the chances of getting Manta plans?


Those guys who watched closely the models used in Carvin in November 2005, would have been able to spot the Manta prototype:

[TRuss]

Tom, I somehow missed your post on the first page. I Didn't mean to be redundant.

[Trisquire]

TRuss,

You had asked how tricky it would be to do a pull-pull arrangement on a bipe. I posted an explanation, and then I realized that KNUFFAN had already answered your question. To my knowledge, there is no way of deleting a post, so I just edited it.

I was being redundant.

Regards,
Tom

[Trisquire]

Those guys who watched closely the models used in Carvin in November 2005, would have been able to spot the Manta prototype:
Another thing I've noticed is that the leading edges have been thickened with some depron doublers.

Regards,
Tom

[Aio_1]

I was considering trying that on my plane. I was thinking I'd thicken and profile the LE.
Do those planes already using thickened LEs have square or rounded edges? I presume rounded!

Aidan

[Jurgen Heilig]

What are the chances of getting Manta plans?

Next to nil - as with all MM Designs - but the model will be kitted with all the accessories. ;)

:) Jürgen

[Jurgen Heilig]

...
Do those planes already using thickened LEs have square or rounded edges? I presume rounded!

Aidan

Correct. ;)

:) Jürgen

[TRuss]

Oh. I love how easy it is to have a miscomunication on these message boards.

Anyway. I was thinking about the holes in the control surfaces of the Manta. I was wondering if maybe they helped clean up the laminar flow, similar to dimples in a golf ball. If the flow after the ailerons in particular could be cleaned up, then maybe the elevator and rudder would be introduced to cleaner less disturbed air, and possibly, be more effective. I also recall from my younger days of being really into warbirds, that the Navy SBD Dauntlas dive-bomber also had swiss-cheesed flaps that ran the full length of the wingspan. I am going to try to Google some information on this plane and see what I can find out about these flaps. I am sure that it was just airbrake, but you hardly ever see footage or photos of these planes without these flaps deployed. Regardless of angle of attack.

[Erik Johansson]

Next to nil - as with all MM Designs - but the model will be kitted with all the accessories. ;)

:) Jürgen

IMO he should consider what some americans are doing, selling plans. At say 12-15 euro (about $15-$18) / plan I bet there are several hundreds of people aroung the globe that would buy them. That sure adds up to some extra pocket money. :)

Just having a simple paypal payment function like Foamyfactory has, that handles everything automatically.

/Erik

[Devin McGRath]

Thickening airfoils hummmmmmm.....

[MKH]

The folks at 3dfoamy have the g-force wing, thickened up from the LE to MAC, and claim all kinds of handling improvements. I may try it on my next foamy.
MKH

[Draganfly]

MKH, I built one of those planes, and experienced no good flying qualities.
-Adam

[MKH]

MKH, I built one of those planes, and experienced no good flying qualities.
-Adam

Hmmmmmmmmmmm... :confused: Thanks for sharing that, maybe some more research is in order!
MKH

[TRuss]

I've been researching this a lot today. It seems that a thin wing is better when you are dealing with low reynolds numbers. i.e. flying very slowly like what we are doing with these indoor planes. In a nutshell, this works because turbulent flow much is introduced much sooner along the airfoil than it would with a thicker airfoil. At low speeds an airfoil that is too thick will be constantly stalled regardless of angle of attack.
At a medium speed it can even reach a point of hysteresis where the airflow is constantly changing from laminar to turbulent, causing extreme instability. This is why flatplate foils seem to work so well for our applications. Because our thin airfoils are seperating the airflow much closer to the leading edge the turbulent flow actually sticks to the surface, instead of a "bubble" forming causing a seperation from the surface, and a stalled characteristic.

There was also mention of "turbulators" which in a sense is similar to the air dams on Devins' F3A, even though he added the airdams for a different reason. These turbulators require a lot of trial and error to get their placement right, but they can also help with this low speed turbulent flow, that sticks to the surface. You can also put a wire in front of the leading edge as well (if I comprehended).

As an avid F1 and CART fan I can recall reading an article on how these guys manipulate airflow. These are openwheel cars, and they use the front aero parts (Every part is an aeropart on an openwheel racecar), such as winglets attatched to the front wing(that is used to force the front wheels downward) to divert the airflow over the car in a most desirable way. These parts basicly act as turbulators, causing a turbulent flow that is easy to control and direct.

I would love to see some of these planes or at least the ideas put to test in a lowspeed windtunnel.

Quiet Flyer did a series of six articles explaining how an airfoil is designed. I have the last four articles. This all came from the fourth article, but I forgot what issue it was.

[dcronkhite]

More than likely the holes turbulate the air keeping the flow attacked.

[Jurgen Heilig]

...
I would love to see some of these planes or at least the ideas put to test in a lowspeed windtunnel.
...

I agree - that would be great.

:) Jürgen

[Alexandre Cruz]

I believe there are two reasons for the holes:

1- They may produce some kind of sound during flight (or may not), as MM loves to add new things for his show.

2-Just like said perttime a champion says his eqquipment is better and top secret so nobody else can concentrate on flying :D

[Aio_1]

More than likely the holes turbulate the air keeping the flow attacked. (attached?)

As the holes are at the trailing edge there is no reason to try and keep the flow attached. There are three possible functions that come to mind (there may be others I'm missing). One is that the holes have no real purpose and they're just there for the hell of it. Two is that they are intended to damp flutter by increasing flow mixing at the trailing edge to prevent the shedding of well defined vortices, this should lead to smoother flight (seems most likely to me). Three is that when the suface is deflected they will increase drag which may be desirable for certain manoevers - but seems it would contribute to adverse yaw.

As I don't have much actual experience with lightweight depron planes (yet!), I'm curious whether there is any "wobbly" behaviour noticable in these planes due to low frequency flow oscillation? On faster, heavier planes vortex shedding is fast enough that it may cause problems with individual control surfaces but won't effect the plane as a whole because the frequency is too high.

Aidan

[Andycap]

The holes could also be there for another reason.

To create a post on RCgroups! to discuss them :-)

[StephanieSchwan]

Hi!

I´ve got some pictures about the missing Minsai.
Juergen gave you pictures of Minsai 2 - 4.
Here are some of Minsai 1:

Best regards,
Stephanie

[Trisquire]

Stephanie,

Thanks for the pictures. It's always interesting to see how Indoor Aerobatics have developed over the years. I suspect that, in the right hands, the Minsai 1 would still be competitive today.

Regards,
Tom

[Azarr]

I love the 3d effect on the Minsai 1, it looks as if the spheres are just floating above the wing.

Azarr
www.ecubedrc.com

[Aio_1]

Stephanie,

I saw the video Jurgen posted of yourself and Martin flying indoor formation - very impressive. I'll bet that took some practice!

Aidan

[StephanieSchwan]

Hi!

@Aidan: We try to fly synchronous the last two years at every fair like the Intermodellbau in Dortmund. But it wasn´t really trained, it was always improvised. But the last training days Martin an me, we worked out a good concept (we think it´s good) and trained it. Now it´s more synchronous and it has good a suspense-structure.
We will show it at the German Indoor Mastership in 10 days and of course at the fair in Dortmund in two weeks.

Best regards,
Stephanie

[Devin McGRath]

Cool I am looking forward to a video.


Devin McGrath
www.devinrocks.com

[Aio_1]

...We will show it at the German Indoor Mastership in 10 days and of course at the fair in Dortmund in two weeks.
I hope someone can get that on video and post it here. Good luck and have fun!

Aidan

[Jurgen Heilig]

I hope someone can get that on video and post it here. Good luck and have fun!

Aidan

I will try, but usually during that time I am doing the documents for the participants.

:) Jürgen

[Trisquire]

Jürgen,

I remember watching another video you had posted. It was about four people flying in formation, including Stephanie and Martin.

Regards,
Tom

[Jurgen Heilig]

Jürgen,

I remember watching another video you had posted. It was about four people flying in formation, including Stephanie and Martin.

Regards,
Tom

Hi Tom,

It was probably this video:

http://www.rcgroups.com/gallery/showphoto.php?photo=26363&sort=1&cat=500&page=3

:) Jürgen