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Raptor Composite Aircraft

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cheapracer

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Sep 8, 2013
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Australian
About a third of the way through I could swear one of the guys says, “It’s so bad,” under his breath.
Way more than once without words, love the bit where Elliot simply walks away rolling his eyes mid conversation while the Raptor Guy just continues to talk on .... and on ...

Can't be inspiring for them when the engine clearly has mapping issues on the ground, what's it going to do in the air ....
 

BBerson

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Dec 16, 2007
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Port Townsend WA
Easier to fit an Eiffel test club. But I think they can estimate the climb rate at liftoff and abort if marginal. I don't know if the test pilots do any quick power to weight and wing loading calculations to double check Mark the designer.
 

cblink.007

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Jul 7, 2014
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Texas, USA
Absolutely. With this much at stake, a few hours of test cell time seems a paltry expense. And the cost/benefit ratio is very favorable.
It would be a worth while thing. We will be doing that with our Yamaha Apex for baseline performance, vibration data collection and engine map characterization & refinement if needed...and those engines have been flying, unlike this Audi diesel!
 

Hephaestus

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Jun 25, 2014
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YMM
Did I get that the AC killed the battery that killed the engine?
The impression I got was that if you throttle back in a specific way - and don't let the controller manage the loads it'll happen.

Wonder if there's an idle detent switch but still have ability to pull lower than idle throttle?
 

Tiger Tim

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Apr 26, 2013
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Thunder Bay
The impression I got was that if you throttle back in a specific way - and don't let the controller manage the loads it'll happen.

Wonder if there's an idle detent switch but still have ability to pull lower than idle throttle?
Sounded to me like when you pull it all the way to the stop it triggers some predetermined fuel schedule for idle but move the throttle slightly above that it’s possible to load up the engine to a point where it bogs below idle speed, or in this case quits. So on the landing roll-out as you smoothly pull the throttle back the RPM will go lower, lower, lower, lower, higher. Seems to me where you put your limits relative to one another for fuel scheduling and prop control have been sorted out decades ago and can be logic’d out today beyond a simple “just use the control so it doesn’t do that.”

I suspect Wasabi’s hesitation over the max RPM is because it sounds like he has it set up in a way that could limit fuel flow below max prop governor setting. If you have your prop speed lever set to 100% and the ECU only allows 95% of that, the prop will go as fine as it can while trying to seek a higher RPM. Hopefully the low pitch stop (if it even exists) is set to a place where you can get some useable thrust, or else the risk is that the prop will go flat (or into reverse if the system design is klutzy enough).
 

BBerson

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Dec 16, 2007
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I doubt the AC draws much electric. But the engine, prop and glass panel and radios probably takes a bunch more than a car. And his battery may be smaller than a car battery. How many minutes after alternator failure?
 

pictsidhe

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Jul 15, 2014
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8,090
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North Carolina
The coal rolling was pretty scary. Suggests that the ECU is not well tuned. It should never run that rich however the throttle is used.

Peter seemed annoyed that Justin had managed to both stall the engine and run the battery flat. Sounds like some ECU and charging issues to me...

I wonder if Peter is regretting asking them to go public?
 
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