9thLife

I posted this on the motor/esc forum, but thought I might add it here as well, considering this forum is more popular..

I have an e-flite thunderboltd that I have recently upgraded to include a brushless outrunner. I combined an e-flite park 480 outrunner (1020kv) with an e-flite 25A ESC with a brand new 2200mah 3s parkzone lipo that I had bought to use with my PZ stryker.

The flight went like this...

I checked everything on the ground, servos all work, range test is fine- motor went to full throttle just fine in my hand, etc...I set it on the runway, hit the throttle and she moved pretty quickly off the ground- about 15 feet into the climb and 20 feet away, the motor cut out. [X(] I nosed it down, rolled to the left a little bit, brought the throttle back to zero and instantly flicked it back to full- the motor responded and I was able to save it.

Being the stubborn fool I am, I decided to gain more altitude and fly, dismissing the earlier trouble. The motor seemed way under powered and speed was basically non existent. I flew it for 5 minutes, then set it down. None of the above components were hot, the battery was slightly warm, and I haven't flown it since.

I want to fly this plane again, I think it's a good looking plane, I've read a lot of posts that say the park 480 is great for this plane, so I want to give it a go again.

My plan is this- although I think it may be flawed...I purchased a master airscrew prop (11x7) and this time I am going to run it at full throttle on the ground for about a minute to see if it cuts out again before I launch-

I have no clue how to calculate watts or amps or voltage....

So RCU..any advice?

Glacier Girl

My Feedback: (4)

Well first tip is to invest in an Astro or Watt meter. A must for electric flight.

Just ran a quick check on MotoCalc, guessing you used the stock prop, which is 10x8, you are pulling 25.7amps. You have a 25 amp esc. Maybe see a problem there.

9thLife

you're right- I am using the stock 10X8- do I go with a smaller prop or a larger ESC?

Glacier Girl

My Feedback: (4)

either. Both would take care of the problem, but again you need the meter.
Dropping the prop down may equate to reduced flight performance.

On mine I used a cheap Tower Pro 2410-9Y motor and 30 amp esc. And I was spinning a 9x7 four blade on it. Slightly lower kv then the 480 you have so I could spin the four blade and only pull less then 17 amps on my set up. That and I spent less then $40.00 for the motor and esc combined.

Lastly. When you get a meter. Wide open throttle is what you want to check your specs on, as in amp draw. That figure, on a brushless motor is what the motor will pull no matter what position the throttle is in.

Don't think that if you lower the throttle is will drop the amps. It doesn't. All it does is reduce the amount of time your pack and motor and esc see that amp draw.

A brushless esc is pretty much nothing more then an on/off switch.
To control speeds it varies the length of time power is applied to the motor.
Kinda like this, low speed is on/off/on/off. medium is more like on/on/off/ on/on/off
and full throttle is on/on/on/on/on.

Meters average readings, so when you reduce throttle you'll see the amps drop. That's where folks get into problems. They think if they stay below full throttle they'll be ok.
Lots of magic smoke leaks out when they try that.

9thLife

thanks GG, I will replace the ESC and get a meter today. Do you think a contributor to this issue could be the lipo? The parkzone 2200 mah has only a 12c max discharge...

Glacier Girl

My Feedback: (4)

Yeah........ 12x2.2=26.4. Good catch on that one. Your pack will thank you if you drop the amps down. And it may last a lot longer too.

Hmmmm, 12C max, what's it rated for constant? Whoa, you may be very close to loosing all the magic smoke in the pack.

9thLife

yeah- I think I'll pick up a 45a ESC and TP 2100 today....

Glacier Girl

My Feedback: (4)

ummm, something else. For getting the most life out of your pack, follow the 80% rule.
Your amp draw should be 80% or less of your packs constant rating.
Taking it easy on your packs will make em last a lot longer, that and keeping them balanced.

9thLife

all set, got the new esc and tp 2100- LHS was out of meters, so I'll pick one up later

patnchris

You really need to get a watt meter and check your set up......I just went through the same problem with one of my planes. .....I bought two brand new Thunder Powers that should have taken it to the moon and back. However, after two flights and bringing the plane in dead stick after only a minute or so, I bench tested it with my watt meter and found the batteries to be giving up and dropping the voltage below LVC, after a minute. I must say that ThunderPower stepped up to the plate and is sending my two brand new TP 3S 2200 ma batteries to replave the 3S 2070 Extremes I had. It appears they had a QC problem. So in the next few days I'll be able to test a couple of the new V-3 Thunderpowers.....Pat

9thLife

brief update- this setup rocks! I got the CC 45, the same eflite 480 and a thunderpower 2100 with 15c, and the stock 10x8 prop- this thing is blistering fast, has unlimited vertical and floats at 25% throttle- it's also silent when not at full throttle!

AETCBoom4

So, what watt meter reading are you pulling now? I'm putting this setup in my GWS P-40 only difference is I have a 33 amp ESC. I take it you are using the stock black 10x8 E-flite prop that came with the kit. I hope the performance will be good.

Leo L

There are many contributers to the various forums who give very good advice. There are a few whose advice is seldom questioned. There are only two whose advice I never question, just take it straight to the bank. One is AEAJR (Ed Anderson). The other is Glacier Girl.

AETCBoom4

9th: Did you have to ream the prop out to make it fit with the 480 prop adapter? If so, how did you do it?

9thLife

no watt meter yet...don't tell GG either...

Yes I did ream the prop out, used a drill bit

afpe45

@9thLife,
I have been reading through this thread with interest, have you used the 11x7 prop yet, and with what were the test results(if you have got a watt meter yet), also do you find the stock 10x8 prop stiff enough at wide open throttle,
afpe45.