Wildthing
Well here is my latest design/build based off the SAB KR84 , high powered little rocket that has to be bungee launched. In mine is the PropDrive EF1 3842 1300kv motor, 200A brick, 7X6 TGS prop and 2 3000 3S batteries hooked inline for 6S fun. Bench testing it produced just over 100 oz thrust, 1770 watts and pulling about 80 amps. Motor is a fat one , heck it is the fattest one I have. Plane weighs in at 53 oz all loaded up, vertical thrust test it is scary at ½ throttle and you really have to hang onto the plane, you hang on so tight you are worried about crushing the foam 😃 . Most of the inner structure is 3D printed with cf rods going through it and then foam formers , canopy, nose and thruster are also 3D printed. I am very nervous on launching this guy, it could be my fastest lawn dart ever. 😊  Bungee hook comes in handy to hang on the wall 🙂 
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https://www.youtube.com/playlist?list=PL8sAtIIQ5wJc9fXqJvwc3CFJwuw-6Jk0o
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solentlife
Remember Hobby King Parkjets ?

On Wattflyer - we had a group called "Need for Speed" .... we were crazy and putting daft power setups into a model that was originally designed for 2S .... and about 70kph.

[HKParkjetarmedandready2]

I fitted a 450 Heli motor of 3700kv ..... 5x5 prop ..... 3S battery .... She hit over 100A at WOT ... so had to be careful. Eventually got her in the air and 222kph recorded on Pitot Speed Tube.

Here's a video of a slow run ... 



Here's the video of the 222 recorded ... sadly the SD card failed for the actual flight .. 



My final was to build one with TWIN motors .... metered at over 1200W .... but could not get her to fly even of catapult ... 

[26233000kvmotors4]
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Wildthing
solentlife wrote:
Remember Hobby King Parkjets ?

On Wattflyer - we had a group called "Need for Speed" .... we were crazy and putting daft power setups into a model that was originally designed for 2S .... and about 70kph.

[HKParkjetarmedandready2]

I fitted a 450 Heli motor of 3700kv ..... 5x5 prop ..... 3S battery .... She hit over 100A at WOT ... so had to be careful. Eventually got her in the air and 222kph recorded on Pitot Speed Tube.

Here's a video of a slow run ... 

solentlife wrote:


Here's the video of the 222 recorded ... sadly the SD card failed for the actual flight .. 

solentlife wrote:


My final was to build one with TWIN motors .... metered at over 1200W .... but could not get her to fly even of catapult ... 

[26233000kvmotors4]


That's cool
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solentlife
Wildthing wrote:


That's cool


Did wonders for the 'heart beat' !!

I actually hit over 240kph with the first one, but could not claim as no recording ... we estimated that if I could have got the 'twin' in the air ... about 300kph.

Here's another video of a 50mm EDF - over 140kph and then another 50mm converted to prop with speeds over 180kph ... 

50mm 6 blade, 5000kv, 4S :



Here's the prop version ...



To be honest, I'm getting a bit old for this sort of thing now ... reflexes not quite what they were !  
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Wildthing
solentlife wrote:


Did wonders for the 'heart beat' !!

I actually hit over 240kph with the first one, but could not claim as no recording ... we estimated that if I could have got the 'twin' in the air ... about 300kph.

Here's another video of a 50mm EDF - over 140kph and then another 50mm converted to prop with speeds over 180kph ... 

50mm 6 blade, 5000kv, 4S :

solentlife wrote:


Here's the prop version ...

solentlife wrote:


To be honest, I'm getting a bit old for this sort of thing now ... reflexes not quite what they were !  


That was pretty quick with the 50mm edf but the pusher is much better 😃 . They don't look that big either, what's the WS if you remember? This guy is 33" give or take a bit. 
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solentlife
Both the PKJ and T45 are 585mm (~23") WS .... 

T45 is the JPowers Skyangel 50mm T45

Parkjet was a Hobby King buy in of a discontinued model ...
I'll fly anything if I can launch it ! Youtube : solentlifeuk
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Wildthing
Well the launch went beautiful, powered up after clear of the bungee probably 30 yards out and away she went. banked to the left (cruising at half throttle and it was cruising) but slowly losing altitude and even with full up elevator it didn't want to climb. Banked left and cut the throttle and that's all she wrote. Massive crater it created . So started printing off a new set of 3D structure, going to build 2 more, one with a lighter 4S setup plus the original. Going to increase my deflection rate (I was slightly more then the actual specs) and going to move the cg back 1/4 to 1/2" back. from spec.
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