oufly2

I have a shock flyer setup with a littlescreamer motor and phoneix 25 speed control,since new anything over 3/4 throttle shuts down the whole system with an express ride to the ground.

This took quite a toll on my first foamy, but I learned to hover and fly pretty good with it.I talked to the littlescreamer people and castle creations several times with no help.

MY last flight was my best I was having a blast and attempted a nice high altitude tumble where I forgot about my little problem for a second, and that was the last flight on that plane.

Can anyone tell me what the problem is with my setup?

Thanks for any help,[][][][]

avalon

Need to know what your setup is first. What battery do you use? It sounds like LVC is kicking in.

oufly2

Thanks for the help,
I have a great planes electrifly 3c 720Mah pack. I have no idea what I'm drawing, I'm using a little screamer with a 8x4.3 prop.

I do have a hobby lobby connector on the battery and a small deans 3 pin connector on the motor/speed control I'm wondering if these connectors are giving me the problems?

I plan on swithcing to deans connectors(battery) and bullet connectors(motor) for the next plane.

Flypaper 2

Do you have a higher amp batt. to borrow, try on it just to make sure the voltage isn't dropping low enough to cause it to cut off. Do you know what the C rating is on that batt. for discharge. Might say on the batt.

Matt Kirsch

My Feedback: (21)

99% chance that the battery can't keep up with the demands of the motor.

3C means the battery is only rated to handle three times its capacity in Amps. 730mAh * 3C = 2.19 Amps MAXIMUM. If your shocky is hovering, it's certainly drawing more than 2.19 Amps. I would estimate that if the battery could handle it, your setup would be drawing 8-10 Amps at full throttle.

When a battery can't handle the Amps, it "knuckles under" and the voltage drops. Then your LVC kicks in and the plane crashes.

I'm surprised that neither the Littlescreamers people nor Castle picked up on that...

You need a better pack, something in the 600-700mAh range that's rated for 10C. OR, you can use Kokam 340 packs, which are rated for 20C.

INeedHelp

My Feedback: (1)

I think he means 3 cell not 3c. I would try a bigger battery though I think it may be to small for this application.

bp2005

oufly2: Buy or borrow a WATT meter so you know what's goin on.
Bob

c-grain

I agree with Bob---get a WATTMETER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!
An electric pilot without a wattmeter is like a sub commander without a depth guage.[sm=bananahead.gif]

oufly2

Thanks guys,
I have a 3 cell eletrifly 720 mah pack and don't know what the rating is but I might try getting a Kokam 340 pack.

I will get a wattmeter if someone can tell me what to do with it?

Flypaper 2

Just testing a couple of Little Screamer motors on the weekend. Apogee 830 ma. batts. on GWS HD 8-4 prop draws 5.8 amps on 3 cells. Worked great. I think they can handle a bigger prop as the motor was only warm. That's where the wattmeter comes in handy, outfly, the apogee batts will handle 10 C so that's 8.3 amps. I can bump up to a bigger prop as the motor is supposed to handle up to 8 amps. and the wattmeter shows me I'm still within the limits all around. Outfly. The watmeter goes between the batt and the ESC and shows Amps, Watts and batt. Voltage while your running the motor. You can see how one is flying blind without it.

oufly2

Thanks I will have to get one if I'm going to go any further into eletrics, any recommendations for a watt meter?

My battery has a 8C discharge rate what does that mean?
Thanks

Flypaper 2

Oufly:
Went to Google/ Electrifly/ batt./ 3 cell 720/ discharge rate or C =8c= 720 times 8 =5.76 amps
Which means, if you put a prop on your motor and the wattmeter says 8 amps when you run it up, means the ESC will shut down shortly when the batt reaches around 9 volts. you can see this happening as you watch the volts on the voltmeter. It's telling you to put a prop on that draws less than 5.76 amps. I use the Astro wattmeter. They don't come with connectors because there are to many different kinds, so get some to fit whatever batt. connectors your using now. Hope this helps.

PS Didn't have much luck with the Kokam 340s .
This is the one I use although there are others on the market. http://www.astroflight.com/e/env/000...-Chargers.html

oufly2

Thanks Gord,
That makes sense I'll have to get one of those and the price isn't too bad.
TC,
Keith

jetranger-RCU

My Feedback: (1)

We had the same problem with a Speed 400 and 1100 nimh pack. Turned out the speed control was shutting down transistors were getting hot for lack of cooling air. Same thing worked at 3/4 but full was too much. Made some cooling vents and now works great