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Looking for help with some projects that require electrical expertise

thorgol1

Feb 9, 2018
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Feb 9, 2018
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We are launching a couple of projects that require some electrical knowledge. One project is basically generating hybrid power to multiple BLDC motors and the two other projects are consumer related low power portable.

We have the ability to produce but are stumped on the electrical. Looking for someone who wants to team up with no obligations, no liabilities and no investments, simply information to some really dumb questions. Should projects come to pass will reap the benefits equally.
 

Alec_t

Jul 7, 2015
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Who are "we"? Students?
Mechanical power sources are usually quite bulky. What are your size limits (in mm, cm or whatever)? "Super tight" doesn't mean much.
 

thorgol1

Feb 9, 2018
4
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Feb 9, 2018
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Who are "we"? Students?
Mechanical power sources are usually quite bulky. What are your size limits (in mm, cm or whatever)? "Super tight" doesn't mean much.
No we are not students. The size requirements begin with weight. Weight limit must be under 250 lb. I am building a quad-copter.
It must have a speed of 40 mph and be able to travel twenty miles without refueling or re-charging and have complete VTOL capabillties.

Pure electric flight would be absolutely perfect but from my little knowledge in electrics tells me this is unattainable due to requirements.

My direction right now is gas powered generation with battery support (take off and landing) and as a safety component should generator fail.

At this point to run the feasibility report I am using 8 80kv brushless motors. Max. continuous power 7000w, max continuous current 115A, idle current around 3.8A ea.
 

Hopup

Jul 5, 2015
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What kind of application it would be used if you can tell? Will the drone have some special equipment in it or is it used for transport a load etc?
 

AnalogKid

Jun 10, 2015
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80 kv x 115 a = 9.2 megawatts. I think there are typos in post #5.

Number of motors -
Nominal motor voltage -
Full load current per motor -

ak
 

kellys_eye

Jun 25, 2010
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Jun 25, 2010
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Have you calculated the maximum lift available from the props?

How does this compare to the unladen weight of the vehicle with a gasoline engine and battery pack installed?

You're looking at an 8.5kVA generator (12hp motor/generator at around 100kg unfuelled) just to generate the base load and, after lift off, a battery pack that would need to have at least 100% over capacity to allow for headwinds, emergencies etc. A 5kWhr LiPo pack weighs in at 75kg.

Assuming a 'get you by' battery size that comprises 100kg of batteries.....

Just the motor (gasoline) or battery pack on their own seem to take up your total vehicle weight, never mind any cargo you might want to carry.

Or are my figures wrong?
 

WHONOES

May 20, 2017
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How about something like a DLE 222cc 2 stroke boxer engine rated at 22.5HP @7500RPM and weighing just 10.5lb (have a look on ebay) mated to a high output car alternator (Volvo do one rated at 245A can run at up to 10,000RPM don't know what it weighs but guess at around 20lb or so). You will need some control circuitry to regulate the O/P of the alternator plus a battery to provide energy for the armature. Neither of those are going to be cheap.
 
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