It appears he was having a difficult time picking out a spot he would like to land on.
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| Dynali helicopter http://skywolverines.com/viewtopic.php?f=6&t=2441 |
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| Author: | Gabor [ Sat Apr 11, 2015 7:13 pm ] |
| Post subject: | Dynali helicopter |
H3 helicopter....no it's not a MINI500 copy....this one actually flies! Pretty machine!!!!!!!!!!!!!! |
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| Author: | RayNAiken [ Sat Apr 11, 2015 8:00 pm ] |
| Post subject: | Re: Dynali helicopter |
It appears he was having a difficult time picking out a spot he would like to land on.
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| Author: | Gabor [ Sat Apr 11, 2015 8:21 pm ] |
| Post subject: | Re: Dynali helicopter |
I really dig this chopper.    
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| Author: | Hillberg [ Sat Apr 11, 2015 8:41 pm ] |
| Post subject: | Re: Dynali helicopter |
Don't like the fake plastic tail boom and the tube at the mid back (a back breaker) the landing gear will bend at the wrong place . engine too small for a two place machine, no flags, gussets or tabs at tube clusters. Little triangulation in design. I'll pass 
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| Author: | MadMuz [ Sun Apr 12, 2015 12:14 am ] |
| Post subject: | Re: Dynali helicopter |
Hillberg wrote: Don't like the fake plastic tail boom and the tube at the mid back (a back breaker) the landing gear will bend at the wrong place . engine too small for a two place machine, no flags, gussets or tabs at tube clusters. Little triangulation in design. I'll pass Apart from those minor issues, it looks ok?  Why cant these small helicopters not have an electric tail rotor? Why do they all have to have zillions of belts and pulleys or gears to drive a tail rotor? Surely a brushless motor and speed controller would work and weigh heaps less than all the gears, pulleys, belts and shafts Then all of the engine power (other than the alternator) would go to the rotors, the tail rotor couldn't overspeed.... Come to think of it, why not have the exhaust turn a turbo, but not to compress air into the motor, but to tap the shaft HP to turn the tail rotor   
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| Author: | Hillberg [ Sun Apr 12, 2015 12:28 am ] |
| Post subject: | Re: Dynali helicopter |
weight, control authority, cost. 5lbs tail rotor & gearbox vs 15lbs (lb per hp ? for electric or was it 10 per hp ? then add controller and what about pitch control or the weight for heavy duty power wire? An aluminum shaft works at less weight then in wire alone.
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| Author: | MadMuz [ Sun Apr 12, 2015 1:04 am ] |
| Post subject: | Re: Dynali helicopter |
Hillberg wrote: weight, control authority, cost. 5lbs tail rotor & gearbox vs 15lbs (lb per hp ? for electric or was it 10 per hp ? then add controller and what about pitch control or the weight for heavy duty power wire? An aluminum shaft works at less weight then in wire alone. I have an inverter in my car so I can get 240 volts anywhere (1000w) and can easily run a 600w angle grinder..... why not have an inverter (about half a #) normal size wiring and a tail rotor gearbox like a real precision built angle grinder and control thrust with rpm/speed (like the rc models) Just a thought it would weigh way less than a conventional kit helicoprer tail rotor system, from pulleys, belts, shafts, the gearbox and pitch system.... then again, if it were a good idea, denise fisters  would have thought about it and designed it already..... twice.... no, 3 times
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| Author: | Gabor [ Sun Apr 12, 2015 7:05 am ] |
| Post subject: | Re: Dynali helicopter |
That is very recent evolving of solid states. I agree to the fact that an inverter would increase the output greatly. I was fiddling with the idea of a strong electric pre-rotator for the tractor. Don is also right about the gearbox being very light weight actually and for that it is very durable. The pitch change is not a problem the way I see it but electric motors still have magnets/electromagnets/iron cores/and heavy copper wires in them. And an ugly short could mess up one's day quickly. The tailrotor spins constantly. I would not trust an electric motor do that for me. Now for a short burst of pre rotation I am in!!!!!!!!!!!!!!!!!! 
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| Author: | elwood [ Sun Apr 12, 2015 7:06 am ] |
| Post subject: | Re: Dynali helicopter |
You can get the Subaru or the rotax...I wonder what the price difference is... |
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| Author: | MadMuz [ Sun Apr 12, 2015 8:04 am ] |
| Post subject: | Re: Dynali helicopter |
Gabor wrote: That is very recent evolving of solid states. I agree to the fact that an inverter would increase the output greatly. I was fiddling with the idea of a strong electric pre-rotator for the tractor. Don is also right about the gearbox being very light weight actually and for that it is very durable. The pitch change is not a problem the way I see it but electric motors still have magnets/electromagnets/iron cores/and heavy copper wires in them. And an ugly short could mess up one's day quickly. The tailrotor spins constantly. I would not trust an electric motor do that for me. Now for a short burst of pre rotation I am in!!!!!!!!!!!!!!!!!! Not that sort of motor Gabs, I am thinking more of a fan setup in a housing around the outside of the tail rotor disk, with just coils spaced around.... would make more power than a motor with an armature like a normal electric motor.... the fan being turned by the tips is far more easy to turn than from the center.... like trying to turn the clothes line by turning the center, or pushing from the outside.... Hopefully someone will try it one day.... the fan would have to work hardest at a hover, at forward speed a fin could do a lot of the work, so the fan can take a holiday at half throttle
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| Author: | Gabor [ Sun Apr 12, 2015 8:12 am ] |
| Post subject: | Re: Dynali helicopter |
Oh a wash machine setup huh? That is light weight. |
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| Author: | elwood [ Sun Apr 12, 2015 8:34 am ] |
| Post subject: | Re: Dynali helicopter |
Sure why not, it all starts here..... Then you upgrade from a vacuum cleaner motor to a washing machine motor... |
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| Author: | elwood [ Sun Apr 12, 2015 8:36 am ] |
| Post subject: | Re: Dynali helicopter |
Then this... |
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| Author: | elwood [ Sun Apr 12, 2015 8:40 am ] |
| Post subject: | Re: Dynali helicopter |
I do like that chopper, but my fave is still the Cicare CH7 But that is just because the CH 14 is not available to civilians. |
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| Author: | MadMuz [ Sun Apr 12, 2015 8:58 am ] |
| Post subject: | Re: Dynali helicopter |
Gabor wrote: Oh a wash machine setup huh? That is light weight. I am thinking of a set of fixed fan blades with a bearing each side on a fixed spindle and a row of coils in the housing around it, sort of like a 'hub motor' and with pitch and rpm to be able to have enough thrust to do a quick stop or do a pedal turn in a hover.... that would be the only time the motor would be running flat out..... otherwise it would only need decreasing rpm, the faster you go.... I reckon it would be good, if the engine driving the rotor fails and you are forced to autorotate, the battery should have enough power to have the tail fan keep operating for a couple of minutes.... that would be amazing to have tail control in an autorotating situation.... We all know that car starters, heaters with fans, washing machine motors etc are designed to only last 5 years..... but if the motors were to be used in aviation, they could be built to NOT fail... they would just cost 10 times the amount  I would trust a purpose built, long life expectancy brushless electric motor over belts, pulleys, bearings, gearboxes etc that have to be where the shaft set up dictates it can be.... an electric shrouded fan could be put anywhere because no shafts driving it........ there is no reason it couldn't be a pitch adjustable fan so you can pedal right or left with a constant rpm.... the pedal doing the most anti torque could have a 'boost button' under the pedal, so if at 3/4 rpm in a quick stop, the machine tries to torque around, pushing the pedal hard will crank up the tail fan speed momentarily.....  I have it all worked out.... lets make one 
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| Author: | RayNAiken [ Sun Apr 12, 2015 10:08 am ] |
| Post subject: | Re: Dynali helicopter |
elwood wrote: I do like that chopper, but my fave is still the Cicare CH7 But that is just because the CH 14 is not available to civilians. I like the looks of the controller in that one. |
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| Author: | MadMuz [ Sun Apr 12, 2015 10:11 am ] |
| Post subject: | Re: Dynali helicopter |
RayNAiken wrote: elwood wrote: I do like that chopper, but my fave is still the Cicare CH7 But that is just because the CH 14 is not available to civilians. I like the looks of the controller in that one. Yes, has a couple of outstanding good points 
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| Author: | Arnie M. [ Sun Apr 12, 2015 2:47 pm ] |
| Post subject: | Re: Dynali helicopter |
. Turning horsepower into electricity (generator) and running the current to an electric motor to turn it back to horsepower is reasonably efficient , not a lot of energy is lost Trouble is they (generator & electric motor) are heavy as hell so aviation ends up at the bottom of the list Top of the list are heavy freight trains , a huge diesel engine turning a generator , and a bunch of electric truck motors in the wheels , nothing works better , smooth as hell , tons of torque , and heavy , which is good for trains. Hydraulic pumps & motors are not very efficient (power loss) but can be more compact & streamlined ... no driveshafts , flex cables , drive wheels etc YADA YADA .... but I keep thinking there may be a better way lurking in some inventors mind I am a slow learner (pre-rotation) .... but (I think) I like what birdy does .... minimum power to pre-rotator (100 rpm or so ) , start the takeoff run (build rpm) (pre-rotator still engaged) , (rudder can overcome remaining torque) , and he is off the ground as fast as if he prerotated to 200 rpm with the brakes on Not sure if I got that right , but it made sense at the time. KEEP INVENTING GUYS !!!!!! . . |
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