your test results are based from engines at idle speed (as in ur other vids) ramp it up- get into the powerband off-on off-on, burn a full tank of gas and then see what your findings are. looks frickin sweet...like many here -i cant wait to see this airborn!
Most runs have ramped up engines all the way and then brought them down to idle. Also, many things we are testing need to be in the worst case scenario. In the case of this project, the highest torque on the drivetrain occurs at startup when blades spin from about 300-500 rpm and within less than a second ramp up to pull speed or about 2700 rpm. What we need to do and plan to do is run through many startups as a shakedown to see what all we can get to break while it is still on the ground.
This is awesome. I've been researching electric quadcopters as a hobby. I'm all about using clean energy sources, but I keep wondering why no one has ever made large gas powered ones. Subscribed for sure.
if you have it centrifugally clutched, id suggest utilizing a torque converter as well to get the rotors up to a constant rpm (giving the rotors a smoother start up to operating rpm). once the rotors are at operating rpm, a main output rotor shaft rpm sensor could vary the engine's rpm slightly in the high range when drag is induced with positive collective. also suggest wider blades which may improve stability, reduce vibrations, increase lift with less induced drag, and might increase critical angle of attack for wider range of aerodynamic lift.
Question: Normal Quadcopters produce yaw by changing the rotation speed of diagonally opposing rotors. Since opposing pairs rotate in the same direction, this causes the torque of the rotors to spin the quadcopter. It looks like on yours, every rotor spins at the same speed and will be controlled by changing the pitch of the rotor blades. How will yaw be produced?
Impressive work guys. Would be great if a proper solution can be found to exceed the 1 hour barrier (for practical multirotors that can actually carry something, not the featherweight stuff with LI ION batts that fly for two hours). I have one question though, what does the stresses look like in those thin looking main rotor shafts when subjected to gyroscopic induced bending loads combined with torque loads...
Awesome machine and great tracking, gotta be tough to setup and calibrate. I'm curious if you will take on inverted flight or just wanted CP so single motor could be used. Massive respect and good luck with the flights.
Hey Incredible HLQ! I have to solute you for what you have accomplished thus far. It really is impressive stuff. I'm curious though, maybe you can answer this. If you've got the dual motors running perfectly in sync, and in turn all four props in sync, how would one then differentiate movement once airborne. Torque is not really going to work and RPMs can't be changed from prop to prop. So what would effectively happen once in the air? Hope and pray that she ain't off balance? 0.o
Hi it's cool project but, How rotates on its axis? The propeller speed should be different for rotation around its axis. How did you solve this problem?
This video being 8 months ago, I have to wonder, was there a failure, or a horrible accident? I doubt fitting the ignition sensors has taken this long.
Wow, this looks awesome! But if you're going gas powered, I think a tandem or conventional helicopter would be more efficient. Not just because of blade/prop efficiency, but drive-train efficiency too. Either way, I can't wait to see the first flight test! I subbed! :-)
Awesomely!! cant wait to see it fly but hey be penitent people!!! let them working first before ready to be fly as test would be nice to see👌amazing patrol engine on large quadcopter! love that! am deaf... big fans of quadcopter.
Im sure it has been answered in the comments, but in an application like this, isn't torque your number one concern? If so, then why the gas/nitro engines? I would bet money that 4 brushless motor setups, carbon fiber tubes, and a multi layer carbon center frame with 4 25000mAh lipo batteries would weigh less and last just as long. I may be wrong, but in my experience that has been the case. Smoother operation for sure. I understand your need to go clutchless, but half of your engineering problems would have been gone with one. Understand I am trying to be constructive. The current build is amazing for what you have.
+Ben Jackbag Mank I don't see this thing flying at all, it seems that all rotors are connected to the same drive. Steering and balancing this is impossible.
+Vlad B Why not? It is using a variable pitch design, not fixed pitch. It's not a traditional direct drive but it still has individual authority over each propeller. It's using a standard off the shelf helicopter swashplate but modified for only pitch movement, no cyclic control.
Were are you located? Im in CT if your close by I have a cnc machine shop and would be willing to lend you a hand (for free) if you ever needed any machining done. I think your really onto something. Goodluck.
Would a turbine engine running the belt produce a better power to weight ratio and better specific fuel consumption and provide more endurance for a given load? i want to build a flying segway like device.
Marc Connell You don't need any rpm change if you're uning a collective pitch setup, the rotors stay the same rpm, but the thrust is controlled via pitch changes. Check out the stingray collective pitch quad, this will give you a better idea of what I'm talking about
Just by the looks of it I'd think this thing alone is waaay to heavy for those blades. Really looking forward to be proven wrong and to see this thing fly.
A internal combustion engine needs a extreme "force" for a split second, for compression. Usually the flywheel provides this "power". At a slow speed like a (electric) start, there's not a lot of power in the flywheel, so the motor has to crank really hard in that moment. With the mass of the propellers, the engine will start easier. I tried that myself, i have a small engine that needed a electric start. So i build one, and it had problems starting the engine. Then i made the flywheel heavier, and suddenly it works great:) (look on my channel if you're interested, the rc nitro submarine)
DerKrawallkeks Your explanation make me think of standard lawnmower engine with the blade on vs off, with the blade on one pull gives extra spin than does with blade off, same is true for the electric start versions.
Why not a use a small 50 cc -90 cc 4 stroke honda motorcycle engines,much better suited,easy and cost effective to repair and or Jobi aircraft electric motors ?These appear to be RC type engines?2 stroke?
This is true. But hen again, we built this as a proof of concept, and not really with maintainability in mind. There are entire engineering disciplines dedicated to that of which none of us have any formal experience with. If we can prove out the concept, we'd love to be able to do a redesign for reduction of weight and better maintainability/usability.
+Incredible HLQ one idea is much like the 4 wheel driveshaft set up they use on rc cars. those mechanisms take a decent beating as well and break mich less than a belt system. not much would have to change in relation to the original design. but vibrations due to lengths may become a concern.
effeciency is lost with gears and shaft setup. the amount of energy required to move and carry the weight required for stable flight, and even distribution of force to all four props. which ae heavy to begin with. plus gears would break under stress where belts would just slip. and doesnt require all the extra stuff. example would need a cover assembly around the gears at each point to keep everything lubricated and sealed. thaat would aslo apply for the gears from the motor to drive all four. it can be done. but at large cost. especially with maintenance.also extra reinforcement because of tortion at each arm. belt drive doesnt cause the same type of directional torque. hope this helped
I do believe you will have serious problem controlling this, you will probably need faster response on rotors than you can get with a liquid fueled craft. I would have tried with one alkohol fueled engine feeding a generator that loads lithium packs and great number of Brushless motors instead.
Motors will stay a constant speed. The blades are collective pitch. They blades themselves will adjust for however he wants to fly. Just like a CP helicopter.
