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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Tue Mar 24, 2015 6:39 pm 
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Efficiency is a curve that apparently falls off at Alex levels

Hey Alex, what was that I heard about your high end radio losing signal and turfing the 880?? Hopefully the case and gimbals didn't feel too cheap and plasticy while that happened... At least you had the feeling of quality...


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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Tue Mar 24, 2015 6:53 pm 
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jv8 wrote:
Efficiency is a curve that apparently falls off at Alex levels

Hey Alex, what was that I heard about your high end radio losing signal and turfing the 880?? Hopefully the case and gimbals didn't feel too cheap and plasticy while that happened... At least you had the feeling of quality...


Lol. I guess? Just not seeing any flight time magic with xnova. Great power. Maybe cooler vs Scorpion. But on the 700's it comes down burning hot to where if I don't cool it with forced air between flights I get strips. Really in struggling to hold on to 3 to 3:30 flight times. On the 700 I run 2150 generally. Nothing insane.

I heard back from Uli. Indeed one of the IC's failed. And was burning hot. He is blaming ESD but a proper FA by the manufacturer (TI) of the IC has not been done yet

For sure the logging architecture of vcontrol is flawed. It no longer stores anything in Vbar. Just vcontrol. So if the rx fails, you get an empty log. Oops.

And yah it felt awesome while t kept making that reconnect chime it makes while my heli dropped like a rock.


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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Tue Mar 24, 2015 7:38 pm 
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Location: Austin, TX
That's too weird about the XNova running that hot, Alex. What timing and PWM are you running on them?

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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Tue Mar 24, 2015 8:20 pm 
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JustPlaneChris wrote:
That's too weird about the XNova running that hot, Alex. What timing and PWM are you running on them?


Well I tend to keep it loaded 100% of the time if I'm in a mode of going all out. Which doesn't help.

I have a couple of diff setups running. One is with a Kosmik 160. Default was with dynamic timing. Which had constant current and thermal shutdowns. In Kontronik land I guess 160 = 120? Anyway I switched to 16 fixed which dropped the kosmik FET temps by 20C and stopped the constant warnings in the log. Motor is as hot as my other setups. It reports peaks of 300A which I find hard to believe.

I also run the same motor on castle 160's, medium, 8khz. Similar high temps.

Now don't get me wrong. I think the cooling fan is better in Xnova vs say Scorp. But there is no magic imo. They are capable of draining the packs just as fast as any motor.

On the 700l I run a 13T pinion, and 110 main. The heat generated in back to back flights is enough to strip the gear easily. So I need to cool it with forced air. It's a 4530-500. On the g700 setups it heats the mother plate sufficiently to generate similar issues where the pinion main gear can strip if not cooled. Adding the heatsink mount helps a bit, but cooling between flights is still needed.

If you guys are interested I can post the castle and Kosmik logs to review the real data. Might be an interesting topic.

Oh and on one g700c I run the metal main gear. It's nice, but very noisy. In a good angry way. It's down to razor blade teeth after about 70 flights so time to replace it. It's not a cheap main gear and pinion set. I think $60? But at least there are fewer surprises in flight. It's a nice option to have.


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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Wed Mar 25, 2015 3:32 am 
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I guess when you are pulling that kind of power through a motor it's just going to get hot!
XNova recommends low (or lower) timing on the Castle, and 12khz:
http://www.xnovamotors.com/xnova-motors-esc-settings/

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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Wed Mar 25, 2015 4:29 am 
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Chris when comparing before and after flight times were you running low timing before?

Less timing advance is supposed to be more efficient at the expense of power.

I ordered an Xnova to replace my Scorpion so we will see if I can reproduce the flight time increase at mild 3D loads.

Metal geared Goblin? Sounds like Chris's nightmare. Now we just need find him an all-metal geared TT tail heli


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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Wed Mar 25, 2015 6:30 am 
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jv8 wrote:
Chris when comparing before and after flight times were you running low timing before?
Nope, I changed nothing at all other than the motor. Since that outing I have adjusted the ESC per XNova's recommendations, but have not had a chance to try the new settings.

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 Post subject: RC Today Show 155: We'll be CNC'n You
PostPosted: Wed Mar 25, 2015 7:46 am 
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Location: McKinney, TX
I got the Xnova for my DT520 a couple of days ago, but with my MR support projects going on, I haven't even taken it out of the shipping box yet.

It'll be interesting to see how it will perform with my Graupner ESC. The PWM frequency is fixed at 32kHz.

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Team Shannon (Only Fine Helis)
DT520E V2, Protos Max V2, Nighthawk 250 Pro FPV quadcopter
ParkZone P-51 BL, Hobby King Skipper


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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Wed Mar 25, 2015 9:08 am 
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After hearing about the Xnova's, I might be ditching my Scorch-me-um 4525 for one!

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 Post subject: Re: RC Today Show 155: We'll be CNC'n You
PostPosted: Fri Apr 03, 2015 6:28 am 
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I'm wondering if/when Helidirect will get their web site fixed.

I was able to access my account last night, but it was painfully slow.

This morning - nothing.

They must be losing money from this problem.

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Rick


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