im working on a custom build using 4 400mm carbon fiber EDF's and trying to choose the right Kv range to turn these monsters. inrunner or outrunner? im not too worried about battery options as it will be powered by a kerosene microturbine/generator set and a voltage regulator (and a small lipo pack to start that). what i am worried about is overheating due to maxing the motors load (turning too slow) or over powering it which could also lower the life of the motor. i was thinking about using dynamite's fuse 9700Kv inrunners but that might not be enough power. any suggestions? i will know more about the impellers weight once it is made but it will consist of a milled aluminum hub with carbon fiber blades estimated weight will be about 150-200g.
You need to be a member of diydrones to add comments!
Replies
im looking at a 42* pitch at the base of the blade rotating to a 35* pitch at the tip of each blade. the shroud surronding the fan is reduced by a 20* angle to begin compression. as for the turbogenerator its a pretty simple design using a diametricly poled magnet (with poles around the circumfrence) on the turbine shaft and the coils surrounding that. a heat shield of stainless with either glass fiber or aerogel mat will keep most of the heat from the combustion section form killing the coils and magnet. +/- wires would be guided through stators in the fan section. the magnet used would have to be SmCo so it can withstand high heat without loosing its magnatism. ive attached 2 quickie (mspaint) drawings of the the rough blade design (2 bolt with a guide pin) and the motor mount/gearbox.
dual ( dual mount gearbox) turnigy E500 4000kv motors? 8 total for the 4 EDF's looking at a 12 tooth gear on each motor then a 96 tooth main gear on the fan mount. i got a guy that will cut me titanium gears cheap enough as well as mill the mount/gearbox once i get it drafted... ill be running 12.4v through the system from the turbine. or should i double up EDF motors like turnigy's 2610 5000kv EDF motors. ill cut 8g off my max weight and boost a little in the max rpm but ill have to run at a lower voltage which means more cooling for the voltage regulator so ill add a few grams in heatsinks and coolers. any ideas guys?
i think im going to go away with the dynamite 9700kv motors, ment for cars/trucks id probably burn them up in one flight....
I will be modifying a KJ-66 microturbine to turn it into a turboalternator (turbogenerator). nice price for parts and plans at marchlabs.com.... http://www.marchlabs.com/kj66_jet_engine_s/29.htm $375 for a parts set with plans.
edit> thermoelectric coolers and heat sinks will be installed on the motors as well.