dhc6twinotter Posted January 7, 2013 Posted January 7, 2013 Awesome! I like the tandem rotor idea much better than the original concept.
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 Thanks guys, you rock! The tandem doesnt yet work, because the 2 battery boxes short circuit protections kicks in, so i need to use 4, but for that i need to additional PF extension cables (8886) which i dont have ATM.
Boxerlego Posted January 7, 2013 Posted January 7, 2013 @Zblj: I really hope you succeed with this flying machine.
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 (edited) And another idea... Each motor powers one rotor! The main axle does not pass through both motors, but splits where motors touch in order to reverse direction of rotors. I can add 1 more blade to each rotor, but im lacking power! EDIT you think the 9V train transfromers would be usefull? Edited January 7, 2013 by Zblj
Carsten Svendsen Posted January 7, 2013 Posted January 7, 2013 EDIT you think the 9V train transfromers would be usefull? No, I know they won't. See the vid I posted further back in this thread for proof
hrontos Posted January 7, 2013 Posted January 7, 2013 (edited) Can you make tandem with just one motor? When motor is able to lift itself, may be even with added gears and friction from one motor tandem it will still work. Edited January 7, 2013 by hrontos
OzBen Posted January 7, 2013 Posted January 7, 2013 LOL i knew you would get there evenutally!! keep going man, im keen to see your ideas evolve
roamingstop Posted January 7, 2013 Posted January 7, 2013 This looks really great and im glad it works. Eould TLG make something - perhaps in NXT series where education is involved. But for average child the risk of hurting fingers is too great. RC heli kits have higher age limits and different branding - but hey id love to be proven wrong I used to run control experiments for masters students using similar helicopter designs on a rotational arm. Eg like rhose made by Quanser Canada. But they always needed a cage to protect the students - more from failing components than finger insertion. Still im looking forward to a complete hover system!
locoworks Posted January 7, 2013 Posted January 7, 2013 Can you make tandem with just one motor? When motor is able to lift itself, may be even with added gears and friction from one motor tandem it will still work. you need to control the speed of each rotor individually to turn the aircraft, by increasing the rotation of one rotor and decreasing the other you keep the same lift but have more torque from one motor anf the aircraft rotates around its main shaft. if you used one motor only the drive train would have to be spot on so that no torqu effect was taking place and this would probably only be the case at a specific RPM. you would also need a small tail rotor to compensate i would imagine so if you have a tail rotor you might aswell have only one main rotor to power. the big issue i imagine would be that the RPM's and loads involved to create lift would likely cause too much friction between rotating shafts and journals that plastic parts under heavy load may melt??
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 I just tried 2 motors with some wires. The thing wants to take off, but not both rotors have same drag, so it tends to rotate in one direction, Like Loco said, i need to control each motor individually.
Sariel Posted January 7, 2013 Posted January 7, 2013 Impressive. Are you running the RC motors on 18V all the time? Are they OK?
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 (edited) The first time i ran them in video the betteries were not full, you can see that when I try to switch off and they work against each other the rotor still spins slowly, menaing one battery box is not as full as another. After few seconds the motor slows down a bit, due to thermal protection, but even when wired directly to batteries there seems to be no damage, but some heat. I think that running RC motors like they were meant in the car, reversing power when full, ETC is harder for them than running constantly as here. Edited January 7, 2013 by Zblj
1974 Posted January 7, 2013 Posted January 7, 2013 EAT THIS!!!!!!!!!!!!!! But that's not flying LEGO. You're not gonna make a battery powered, steerable LEGO MOC with current parts Not gonna happen. At all. Ever. Ok? Think I'm stupid? I' urge you to join some RC fora and display your MOC and future plans
Lipko Posted January 7, 2013 Posted January 7, 2013 My girlfriend says you take a Boeing plane, put a Lego logo on it and a stud, and you have your flying Lego. I'm breaking up with her.
legolijntje Posted January 7, 2013 Posted January 7, 2013 My girlfriend says you take a Boeing plane, put a Lego logo on it and a stud, and you have your flying Lego. I'm breaking up with her. :laugh: @Zblj That looks great, maybe you make the PF extension cable longer and remove the arm so it would really fly?
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 If i remove arm the single motor will spin out of control :)
hrontos Posted January 7, 2013 Posted January 7, 2013 I just tried 2 motors with some wires. The thing wants to take off, but not both rotors have same drag, so it tends to rotate in one direction, Like Loco said, i need to control each motor individually. Yes, I know that for steering and stable flight without unwanted rotation it is necessary to control the speed of each motor individually. My suggestion was only a temporary solution to see it really flying. Until you will have the needed wires and batteries. You will probably need very a smooth speed controller and not stepping one.
Zerobricks Posted January 7, 2013 Author Posted January 7, 2013 I tried it with a built tail rotor, powered by same motor as the one for lift and it does fly, but it extremely unstable, swaying to the side and crashing.
hrontos Posted January 7, 2013 Posted January 7, 2013 But that's not flying LEGO. You're not gonna make a battery powered, steerable LEGO MOC with current parts It's a matter of your expectations. A few years ago nobody expected from Jeniffer Clark's excavator to integrate motors with pumps, it was acceptable to have cables and air hoses there and controller in hands. Now it is an iconic demonstration of creativity and possibilities of LEGO those days. And now there is full RC 8043. So why not have now first cable controlled LEGO helicopter? And in few years a real one.
legolijntje Posted January 7, 2013 Posted January 7, 2013 If i remove arm the single motor will spin out of control :) Of course! Stupid of me
1974 Posted January 7, 2013 Posted January 7, 2013 What JC did, did not exceed my expectations of what LEGO can do (or more correctly, what one can do with LEGO). That's evolution, not revolution .. Zbij, if she buys that plane - marry her
1974 Posted January 7, 2013 Posted January 7, 2013 .. in few years a real one. If someone makes a proper RC controlled (no power umbilical, sorry) 'copter using LEGO parts, I'll gladly eat my words AND a properly cooked and prepared 2x8 brick with a nice Shiraz to boot Of course with a youtube vid for full documentation I applaud you gentlemen for your endeavours, but it really is futile. LEGO parts simply does not have the power versus weight ratio to make it happen
Conchas Posted January 7, 2013 Posted January 7, 2013 If someone makes a proper RC controlled (no power umbilical, sorry) 'copter using LEGO parts, I'll gladly eat my words AND a properly cooked and prepared 2x8 brick with a nice Shiraz to boot Of course with a youtube vid for full documentation I applaud you gentlemen for your endeavours, but it really is futile. LEGO parts simply does not have the power versus weight ratio to make it happen Support! I've tried this myself two years ago and indeed it will not happen in a controlled manner, at least with current parts.
hrontos Posted January 7, 2013 Posted January 7, 2013 I applaud you gentlemen for your endeavours, but it really is futile. LEGO parts simply does not have the power versus weight ratio to make it happen It is not necessary to eat any bricks. :-) Nobody denies, that it is to heavy and not powerfull enough to fly like a real model. I personally do not expect it to fly with batteries. But it would be nice if it could fly with a 5m long cable. 2 weeks ago it looked like motor is not able to lift itself. Now it can fly. And if in a few years, LEGO will produce RC unit with metalic axles and other parts sturdy enough to be a core of some simple helicopter, that will be the real one. But Zblj will keep his credit for being first pioneer in LEGO flying.
1974 Posted January 7, 2013 Posted January 7, 2013 I don't think TLG will do that .. allthough they did make RC cars that was pretty much non system LEGO. But a flying 'thing' would need so many special parts I doubt that TLG will go into that. I also think they're not wanting to compete with the whole RC world as such But what do I know, the future is hard to predict Yeah, kudos to Zblj .. but he has very good LEGO skills, I just think it's wasted on this project. Imho that is ..
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