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View Full Version : Going to give Electircs one more try, but need some help


Spectrepilot
03-12-2007, 04:28 AM
I am a 20+ year nitro flyer and last year I decided to try the electric side of things. I purchased a used Mini-Funtana (I fly the 90 size and like the plane), which came with a Castle Creations ESC (I think it is a 45, but it does not have any numbers I can see), and AXi 2808/24, and two 210MHA three cell batteries.

Everything was assembled so I used the Li Poly charger and charged the batteries, programmed my radio and went to the local park to give it a try. I took off and after about 30 second the engine throttled back to idle on me. This happened numerous times despite changing batteries and confirming recharging.

I brought everything home and did some research on here about programming the ESC. I ordered the harness from Castle and confirmed the ESC was set properly. I went back to the field and had the exact same experience. I called the guy I bought it from and he swore he never had a problem. At that point that batteries were six months old judging from the date stamp on the battery pack. One guy in my club mentioned it might be the temperature (Washington DC in the winter – lower 30’s), but I tried keeping the batteries warm in the truck and had the same experience.

On my last outing I managed the engine dropped of and the resulting dead-stick landing took off the gear. I was so frustrated I put the whole mess in a box and have not touched it since. I’ve decided to give it one more try before I throw this mess in the trash and I need a bit of help.

I think I am going to try a new battery and see what happens. I have since moved to Florida so I don’t think the temperature will be and issue (not convinced it ever was).

Can you guys recommend a battery and place to purchase LiPos?

The pack I have has a ‘Thunder Power” label and it says it is three cells and 11.1V. It also says 15C Cont/20C burst(31.5A/42A).

I will also take any other suggestions to keep from giving up on electrics.

Thanks

Spectrepilot

skiman762
03-12-2007, 04:57 AM
We will need more details
What are the esc settings
What size prop
what charger are you using
also if you have a volt meter give the readings form the fully charged batteries

sounds like your hitting cutoff
6 month old batteries should be fine if they haven't been abused
CC makes a good esc

Spectrepilot
03-12-2007, 05:13 AM
I tried all sorts of ESC settings including setting the cutoff at 6...same result.

Prop is an APC 10x3.8.


Charger is the Thunder Power TP-425.

Don't have a voltmeter, I guess I should break down and buy one.

I have the TRITON Electricfly charger for my nitro plane packs and it has a connector that would fit my Thunderpower packs, but i don;t know if that charger works on LiPos.
.

skiman762
03-12-2007, 05:20 AM
Just a dumb question but what rx is in it

Spectrepilot
03-12-2007, 05:35 AM
Hitec Electron 6

skiman762
03-12-2007, 05:48 AM
I know they have two versions for negitive futaba and positive JR
I know you are a seasoned flyer but I just want to help eleminate some common problems
some esc's will cut the motor off if it loses the signal

what would be easiest if you have a rx from one of your other planes you might try that on the ground just plug the esc into the thorttle port and see if it will run WOT with out cutting off

skiman762
03-12-2007, 05:51 AM
Before you spend money on new batteries you might pick up a smaller prop like a 8x4 something that won't load the motor down and see if it will run with that if so it may well be the batteries but it would be odd the both are bad but it could happen

Solid Hit
03-12-2007, 12:36 PM
Your motor/prop/battery/esc is fine for the plane you have. It sounds more like your batteries are not fully charging. You need a watt meter to determine battery charge underload and watts going in. Just for information, what rx are you using?

Slowjohn
03-12-2007, 01:47 PM
From post # 1;
"and two 210MHA three cell batteries."

I'm guessing you meant ...2100mAh three cell batteries. Did you try cycling the throttle stick back to low throttle and then throttling back up to a lower throttle setting? If so, what happened?

SJ

Solid Hit
03-12-2007, 03:20 PM
From post # 1;
"and two 210MHA three cell batteries."

I'm guessing you meant ...2100mAh three cell batteries. Did you try cycling the throttle stick back to low throttle and then throttling back up to a lower throttle setting? If so, what happened?

SJ
I'm guessing a typo as well, at least I hope so!

If the esc was not arming (what I think you are suggesting) then the motor would not come on at all. I don't think he is overamping with the setup he has but there is one other explantion and that is his motor/esc connection is not proper.

Spectre, are your trim setting on the throttle at the lowest setting and is your throttle stick at the lowest setting when you plug in your battery?

If the batteries are at full charge, and your servos are working, then there may be a problem with the motor connection. Perhaps the three wires are not making good contact or one is shorted somehow. I'd like to know what connectors you are using for the motor/esc.

All that being said, the fact that the motor "dropped off and went to idle" really indicates a bad charge if the battery is good.

Slowjohn
03-12-2007, 04:21 PM
Actually I had a similar situation where my battery wasn't quite strong enough for the prop I was using. My first two flights on that battery/prop combo were fine. The next day I'd get airborne and start a turn when my motor would cut-off. I found that by throttling all the way back and then going to half or even 3/4 throttle I could fly. If I went past 3/4 throttle it would cut-off again. I'd have to recycle the throttle and land then change props till I found one that wouldn't cause the motor to cut-off at full throttle. After going to a bigger mAh battery with a larger C rating, I didn't have that problem any more. That's what I was thinking about. Since I'm not familar with his set-up...

SJ

Solid Hit
03-12-2007, 04:32 PM
Hi Slowjohn, I think your effect is caused by "over amping" or using a battery with a low discharge rate, but that setup should be fine if all the equipment is in good shape. If it were my plane, and I didn't want to invest in a watt meter, I would drop to a 9x6 SF and see what happens. \\ This is exactly were a watt meter is worth it's weight in gold.

Slowjohn
03-12-2007, 05:00 PM
Hey Solid Hit,
I'm still new to this electric stuff after being away from the hobby for about 26 yrs. or so. Jeff at www.headsuprc (http://www.headsuprc) has been such a big help to me even before I got some of his equipment. There's no telling how many hours I've spent reading the WattFlyer forums also and I've learned a ton of info here as well. A wattmeter is almost a must I know but I've yet to buy one. I'm sure Jeff would appreciate it as It'd most likely free up some of his time. The battery I was using was a brand new one so I'm guessing that's the reason I got away with using full throttle the first few flights or else I was throttling back before it had a chance to cut-off. Anyway Jeff knew what I had so he spotted it right away. I now have the proper batteries so now I just need to get another transmission put in my "Aircraft Carrier" Astro van and some good flying days. I have 5 planes that need to be maidened. The Brown Truck has been here alot lately.:D

SJ

Solid Hit
03-12-2007, 05:40 PM
Slowjohn, I got back in the hobby exactly one year ago from a 30 year absence myself. Electric is way different but more enjoyable to me. I own 25 acres with a lake on one side so electric is very convenient for me. I work from home and electic enables me to take a break and fly a pack during the day. There is a learning curve as there is with all things but it comes quickly if you follow the forums.

I've got 11 planes flying at the moment with a few kits waiting in the background - and a pile of motors, batteries, esc, screws, and so on and so on. Addictive isn't it?

Slowjohn
03-12-2007, 06:36 PM
Several yrs. ago I got real sick and came way to close to dying but they forgot to tell me to stop breathing so now I'm disabled from thinking I was bullet proof. I saw an ad in a magazine at the Doc's office for electric planes and that was all it took. I bought a bunch of stuff I wound up not being able to use at first but am slowly finding use for most of it. I don't even want to know how many kits and plans I have stashed or I'd have to answer the wife when she ask. I'm enjoying myself more than ever and have the time to build all I want just not enough money to go along with it. It's the best way I can think of to spend my time and sometimes I'm able to help someone else so that's satisfying also. Sounds like you've got a great place to fly and enjoy yourself. We're planning to move and I'll have the area to fly right out the back door then. I can hardly wait.
Now if we can get Spectrepilot fixed up he can enjoy electrics also. I'm just sorry I waited so long before I started asking questions. Electrical never did come easy to me but I've found there are plenty of folks out there willing to lend a stranger/newbie a helping hand just for asking.
Thanks to all of those out there who've helped me! :D
SJ

JWilliams
03-12-2007, 08:00 PM
Electrics do work fine in cold. I took one out on Friday morning and it was about 8 F outside and it was fine (battery did come straight from the house, though, so it started at room temp), so that's not a cause of problems.

skiman762
03-13-2007, 01:08 AM
Maybe he can tell us what his charger setup is and we can tell if he's getting a good charge

Spectrepilot
03-13-2007, 02:24 AM
Sorry guys just got home from work. I will try to answer all questions here;

1. The Hitec RX is a Futaba Negative Shift Low - I have a nice Futaba 8 Channel compter radio on 29.

2. The servos continue to work when the throttle drops off. Suspecting the ESC I have recycled the throttle to idle and sometime the power will come back up, but only for a few seconds before it drops off again.

3. I am using the Thunder Power TP-425 charger.

4. Yes the 210MH was a typo, my batteries are 2100MH.

skiman762
03-13-2007, 03:00 AM
Are you sure you have the charger setting correct for your battery ?
How long does the battery take to charge ?

Dereck
03-13-2007, 03:05 AM
Hi There
Idle thoughts that spring to mind - apart from "What is a guy who lives in Florida doing in the Disaster of Columbia in the winter?" (I live in Potomac, just outside the DC beltway, MD side ;) )

Then I read further, to discover that you'd moved permanently and just felt jealous for a while :)

LiPo batteries - being a 'late adopter', I only have a few, and still aren't certain that they what we really need. That many marketing depts. think we should buy them is another angle... Despite the age of yours, they could be what we Brits term 'clapped out' though. One thing you could try is to run them with a smaller prop, to put a lower load on them, see if they run longer and behave better.

Do you have a way of measuring the current in your motor circuit? The grand-daddy of these devices is the AstroFlight Wattmeter, which goes between battery and ESC and can measure horrendous amounts of current plus tell you other good stuff, but the Chinese manufacturing machine is now geared up to produce ripoffs of this venerable tool, which are available all over the cut-price world of the internet.

The bottom line is that if you over-draw current on an electric drivetrain, it can get far more costly than a lean run on a glow engine, and you won't know you're going there without something like a Wattmeter.

There's also a possibility of LiPos doing a real good impersonation of an explosion too. You might care to read around about their baser habits, invest in a steel toolbox to store and charge them in and not keep them lying around anything combustible, like your house, car, etc. The record so far is probably shared by the guy who well-night burned out his basement and the one who burned out his Lexus Landcruiser truck, both courtesy of upset lipo batteries of no great size.

I have a feeling that most ready-made models are pretty weak around the UC mount, and possibly many other places, but it's not a popular viewpoint in this era. It's something you have to live with, or move to the 'if you want it doing right, do it yourself' side of things. After a few electrics, mine do not have their UCs fitted anything like the ready-mades I've seen...

Hope that helps

Dereck

Solid Hit
03-13-2007, 03:07 AM
3 Choices,

1. You are over amping the esc - not as likely as the next two
2. Poor connection between the esc and the motor - possible
3. Battery not charging properly - possible

If you have another esc that could help a great deal. Double check the solder joints as well. I still think it is in the battery. Unless the battery has been really abused (you may see some swelling as well), a battery is good for about 200 - 250 cycles but if it is not chargeing properly, you will not get full bennifit from it. A watt meter will tell you a lot.

Spectrepilot
03-13-2007, 03:29 AM
The settings for the Charger are as follows;

1. C.V-CHG - 3CL

2. C. C-CHG - 2.0A

I don't recall how long it took to charge, as I did not time it, but I am guessing around 15-20 minutes.


I just tried to charge on of the batteries and the charger starts beeping within a few seconds as if it is full, but when I hook that battery up it is totally dead.

Can anyone recommend a reasonable wattmeter?

skiman762
03-13-2007, 03:44 AM
One of the first three are about as good as it gets depends on what connectors you use
It sure sounds like your batteries may have been over discharged but it's strange your esc would arm



http://www.astroflight.com/store/store-Chargers.html?sid=00019svjbSHfuE0lRA884j9

skiman762
03-13-2007, 03:59 AM
Is the battery full light on when it beeps ?

When charge is complete, the FULL LED should be solid ON and beep alters 6 times in a minute for 5 minutes

When “CHARGE” LED (Blue)” and “FULL” LED (Green)” both are flashing with a beep, there are something wrong

Solid Hit
03-13-2007, 04:06 AM
This is the one I use. I like it because it shows all readings on one screen without having to scroll through the meter.

http://www.rcuniverse.com/magazine/article_display.cfm?article_id=468

If you know anyone with a different charger try charging on that one if you can before buying a new battery.

skiman762
03-13-2007, 04:09 AM
Yep just like the astroflight does pretty simple
looks like it has a few more features and doesn't cost that much more either

skiman762
03-13-2007, 04:13 AM
Well the first thing in basic electronic trouble shooting is to check the power so I think the battery status needs to determined first