Help me make a flying helicopter!

[AVCampos]

Wow, the helicopter thread has become an airplane thread...

Anyway, I tried a few moments ago a rotor I designed with three 9396 blades angled at about 14.5º, connected to an RC motor powered from a 9V train regulator. In a word: disappointing. At least it showed that I can push the setup a little bit further without triggering the regulator's over-current protection. I'll try adding more blades and angling them more aggressively. If only the blades weren't so expensive!

[TotalyWicked]

I seen a video.of a Guy using old NTX brick to control a kite. Let me see if I can find it.

Also has anybody put their motor and prop on small scale to see how much thrust is generated???

I use to do that all the time, for scratch build RC planes...

Edited January 18, 2013 by TotalyWicked

[piterx]

unfortunately i have no legos with me at the moment :( ill be operative again in april...

btw let's not forget about gearing propellers :P we can achieve so much speed!

[SkyrateShadowStorm]

ZBLJ, wouldn't it be easier to give it wheels and put the power pack on it instead of holding it? If the speed of the propeller is enough to make it fly it will be able to do so on its own wheels and with the battery pack.

[AndyCW]

I can contribute what little I know about propellers.

These are rules of thumb. They do not apply in all situations.

• The length of the prop determines static thrust.
  
• The pitch of a prop determines pitch speed.
  
• The fewer blades on a prop the more efficient it is.
  
• Reduction drives reduce efficiency
  

What little I know about wings

• Long wingspan and short chord wings are the most efficient
  
• Short stubby "hershey bar" wings are easy to make, strong, and have good stall characteristics
  
• Delta wings have poor stall characteristics
  

The power requirements for rotorcraft far exceed the requirement for fixed wing aircraft. For example, a 1946 Taylorcraft outfitted with a Continental engine produced 85hp and has a maximum gross takeoff weight of 1500 lbs. This aircraft has sufficient performance. A mosquito helicopter equipped with a MZ301 engine also makes 85hp and has a maximum gross takeoff weight of 720 lbs. It has sufficient performance. The size and weight difference between these two types of aircraft is large. The power limitations of lego make a fixed wing model much more likely to fly than a rotorcraft, given that a suitable wing and fuselage structure can be assembled.

http://en.wikipedia.org/wiki/Taylorcraft_B

http://www.composite-fx.com/compfx/XE3.html

A control line model may be the best interim solution. This would allow you to leave the batteries out of the airframe by using long power cables. You could focus on structural integrity, controlability, and lift. WIth these things resolved, you could then transition into free flight with batteries aboard and then free controllable flight.

http://en.wikipedia.org/wiki/Control_line

v/r

Andy

**I am pursuing a degree in aeronautics, am employed as a unmanned aircraft pilot, and I have my pilots license. I also fly RC planes in my spare time.

[piterx]

has anyone tried this propeller? it seems good...

i wonder if a geared up M motor can generate enough speed...that would be cool in terms of weight :P

[piterx]

:P cool!

this one is very intresting....maybe zblj, you have to consider re-designing the surface of the wing...

and this? it seems not lifting like an helicopter, its inbetween an heli and a plane lol

Edited January 19, 2013 by piterx

[Zerobricks]

So here it is, first few seconds of sustained flight with Lego. Too bad that the cable soon tangled and caused the thing to crash down.

For now I will wait for snow to melt with the kites, etc...

[rm8]

You need many many 50cm pf-9v cables ;) the man that makes lego fly:)

[z3_2drive]

any stronger materials for wing skeleton? seems like only thing keeping it from flight...bends then loses lift...this plus longer cable as mentioned above would be great

Edited January 19, 2013 by z3_2drive

[piterx]

:-D i knew it! I f#/!?;:##g knew it !!!! AWESOME DUDE! !!!

[RohanBeckett]

So here it is, first few seconds of sustained flight with Lego. Too bad that the cable soon tangled and caused the thing to crash down.

although I personally won't count that as 'true powered-lego-flight'... I will admit that that video is *hilarious*, and looks like you had a lot of fun!

c'mon... you used trash bags as wings... (non lego part).. just go ahead and get 10metres of cheap/lightweight wire.. and be done with it..

heck.. you could probably make some sort of control-line plane, that goes in circles (add another motor for elevator control??)

[Zerobricks]

although I personally won't count that as 'true powered-lego-flight'... I will admit that that video is *hilarious*, and looks like you had a lot of fun!

c'mon... you used trash bags as wings... (non lego part).. just go ahead and get 10metres of cheap/lightweight wire.. and be done with it..

heck.. you could probably make some sort of control-line plane, that goes in circles (add another motor for elevator control??)

Well TLG also used such materials in their models, so i dont see the issue.

[piterx]

use the lego bag as someone was suggesting xD

anyway, future tests, in my opinion, should be:

- how many rpm do you need to make it fly (maybe a geared M motor could work too)

- finding out minimum speed required to fly

- improvements for the wing frame to avoid all that bending

- testing 42002 propeller

btw i can't wait to get back to italy and test it all by myself :D

great job man!

Edited January 19, 2013 by piterx

[DLuders]

The clingy plastic wrap (used for storing leftover food) is very strong and useful to cover the wing frames. When the plane crashes, one can easily see where the damage is and repair it:

Edited January 19, 2013 by DLuders

[piterx]

yeah i was suggesting that some posts ago but i don't even know its name in italian ahahah

[AndyCW]

The material used in covering RC planes is commonly known as Monokote. It provides a cleaner surface and contributes to the models overall strength.

[freakwave]

There is an interesting thread over at the German 1000steine forum.

A guy (Axel) made the 9396 fly by putting a Heli-RC Unit into the body. So it is basically a naked RC-Heli with a 9396 body! The RC-Unit is covered pretty well!

Complete with video:

[media]

[/media] Edited January 25, 2013 by freakwave

[Conchas]

Never thought an RC unit like that could support all the 9396 height. Even if it is only the outer shell.

Amazing! Well done!!

[hrontos]

This video look really great. It's really interesting, that the RC unit and blades of that size can handle the 9396 body. It is not very smooth body comparing to traditional RC heli bodies and it's definitely heavier than those bodies. May be he selected some stronger motors and batteries to handle it even with 9396 sized rotors.

[AussieJimbo]

That is uber cool.

Thanks for sharing, freakwave.

I'm surprised how well it flys too. Looks like it's totally controllable and not at all sketchy.

Given this thing flys nicely, how about a double rotor LEGO Chinook.

:classic:

[AVCampos]

I can't wait to watch that video (it's inconvenient to do that at work)!

As for a Chinook-like all-LEGO helicopter, at least with the same configuration (two three-bladed rotors), I can say it's not possible. I tried a few weeks ago a three-bladed rotor made with 9396 blades, connected to an RC motor and powered by a train regulator (10 V), and it gave nothing more than a gentle breeze... When I have time, I'll try to figure out a design capable of securely holding 6 blades and with a more aggressive pitch.

[Tamas Juhasz]

"flugfähiger RC LEGO Heli" - it sounds interesting, because all of the RC parts and motors, etc. aren't Lego. It is equal with a regular RC helicopter which carries weight. Why makes it sense to do this with a Lego body? I see nowadays even more models which have a lot of custom parts(like this), and with these the essence(building creative mocs with Lego technic parts) of Lego technic is loosing.

A few(1-2) custom parts or custom wheels(like many of us used them in crawlers) aren't makes a moc non-Lego, that's absolute ok.

Edited January 25, 2013 by Mbmc

[hrontos]

"flugfähiger RC LEGO Heli" - it sounds inetersting, because all of the RC parts and motors, etc. aren't Lego. It is equal with a regular RC helicopter which carries weight. Why makes it sense to do this with a Lego body? I see nowadays even more models which have a lot of custom parts(like this), and with these the essence(building creative mocs with Lego technic parts) of Lego technic is loosing.

A few(1-2) custom parts or custom wheels(like many of us used them in crawlers) aren't makes a moc non-Lego, that's absolute ok.

Yes, it is a regular heli with LEGO "weights", but it is nicely integrated and flies nicely.

Some famous RC heli producer should negotiate with TLG and put some aluminium pins into their kits and LEGO logo on them to satisfy also purists.

[Tamas Juhasz]

Yes, my problem is that it's called a LEGO heli with those lot of custom parts.

Some famous RC heli producer should negotiate with TLG and put some aluminium pins into their kits and LEGO logo on them to satisfy also purists.

Edited January 25, 2013 by Mbmc