This must be the best sell pitch ever or just their fantasy.
But still, if somebody can come up with a formula ( battery size , prop size,
motor ) to get at less 50% of that it would be great .
This are the specs for the MD4-1000 from the MicroDrones
Empty weight 2650g
Max payload weight 1200g
Take-off weight ~5500g
Size 102cm rotoraxis-rotoraxis
Flight duration up to 60 min
Operating distance up to 2000m
Battery cell LiPo 9000, 18000 or 27000 mAh
Wind tolerance 12 m/s
I don't know why the maximum flight time is tested in hover. At least in traditional helicopters the maximum flight time is achieved with some forward speed as you can see from the graph.
I'm not sure how directly the graph is usable with quads or hexas which have rigid rotor system.
But perhaps someone could test it by flying with different airspeeds at the same height and at the same time check how many amps is going to the engines.
When traveling fwd in an normal heli, you have relative wind due to the fwd movment throuh the air. The blade angle of the blade moving fwd is reduced, and the blade moving back is increased due to the decrease of relative wind speed.
Since we do not have this on quads, I would guess that this principle would be valid due to the rigid rotors we use.
But I am not 100% sure!
Sorry to resurrect an old thread but had a couple questions. I'm in the process of developing a VTOL quad for extremely high endurance.
I noticed one of the posters, Maximus, had access to some really nice low KV, high torque motors. Does anyone else know where I can go to find suitable props, motors, etc... for this task?
RC tiger motor MT series, Hobbyking NX series motors for multirotors. Been using the NX-4005 650kV and the MT3506 650kV for my builds with really good results. High stator and pole count. These motors are really quite. You may also want to check out the 5010-14 360kV outrunner from rctimer.com. Motors such as this will provide more torque to turn a larger high static thrust prop. I am drawing literally half the amount of current with these motors than I was with motors that had fewer stators and magnets. Good luck:)
Todd could give specifics about your setup as in :
Amount of Battery (mAh)
Weight of Battery (gms)
Flight Time at hover (min)
Along with the motor used....
My motors are 24 poles, nothing to do with RCTimer (12 poles) or other low quality motors
nobody knows that MD used lithium-sulfur batteries that gives 3 times flight time of Lipos....but very low number of cycles !!!
@Todd, Thanks for info. How much flight time are you getting with the above mentioned 4S 5Ah battery ??
Thanks for your reply guys. I have several days of hands on experience with the MD4-1000 and with 6s lipo batteries and a standard point and shoot camera we were getting around 40 minutes of usable flight time. There is just no way MD can claim that amount of flight time with the same setup. They have to be using primary batteries as Maximus suggested. @Maximus can you confirm this?
I've been looking into the rctimer 5010 motor and I've noticed a few have compained about quality but it looks exactly like the motor I need for the job. I's like to try Maximus' motors but they are very heavy and not sure how they would do with much bigger props.
@ Brian, rctimer will do custom stator wrapping to match the kV you need, or if you have a little experience you can re-wrap them yourself. I usually replace the bearings on all of the budget motors I buy, as they are generally weak. You may also want to check AHM brushless motors, but they are pricey. They also sell the parts to build motors yourself for a lot less. Just giving you some options.