naveed

Hello everyone,
I am new to RC and at present learning to fly my Hobbico superstar EP. The problem is shot flight timings varying between 4 to 6 minutes. first weekend in the field was really disappointing as I required 45 minutes to recharge the battery before next flight meanwhile those with gas powered planes seemed to be well in control and were really having good time. Even the second battery pack I have recently purchased doesnot rotate well.
I have recently gone through a lot of posts suggesting numerious combinations of motor/gears/propellers but one combination figures out very prominent and that includes :-
a. GD 600 gear
b. Endoplasma motor
c. 50 amp esc
d. Bigger propeller and wheels
e. Lipo battery
since I am on a budget I would like to to retain max possible stock items and upgrade on minimum essentials like motor,gear and propeller while keeping the stock esc and battery.Besides I would like to know how different ratios for gear like 3:1 etc and size/pitch of propeller effect flight.
As I am outside US therefore please give me sold recommendations on best combination along with the site to get them from .I will get the items through a friend who will be visiting me shortly.
Thanks

Matt Kirsch

My Feedback: (21)

First off, we need to determine if the batteries you have are adequate. It sounds like that's the trouble you're having. What exact batteries are you using with this airplane now? It's very easy to choose the wrong battery pack if you're basing your choices on the wrong criteria. I've seen these planes fly very well, and get flights around 8 minutes.

In an electric R/C plane, the power comes from the battery. If the battery can't provide enough power as it is, it won't matter what motor you put on the plane; it still won't have any more power, or fly any longer.

The biggest upgrade you can make to the plane, if the battery is okay, is to add a gearbox, even to the stock motor. A larger prop spinning slower gets a better "bite" on the air, and better matches the speed the airplane can fly at, so the overall efficiency goes waaaay up. As far as the specific gear goes, pick one you've seen and have your friend pick it up for you. The Kyosho Endoplasma and GD600 gearbox are Tower Hobbies items; you can get them elsewhere, but since Tower is owned by the distributor of these items, they're the ones most likely to have the best price, and the ones to most likely have them in stock.

Gearing down the motor allows you to turn that bigger prop because the gear train multiplies the motor's torque, at the expense of RPM.

neww2rc

Hi Naveed

The SuperStar EP is a great plane to learn on and even use as a sport plane when ready. We use GP 3300 7 cell packs and with the stock T 601 motor we could get up to 13 min with mixed flying incl. taxi out ROG, land and taxi back. Now with the aileron wing Endo combo it is usually 10 to 12 min due to the third servo and how hard it is to stay out of the power with the Endo on her . Sad to report the Endo looks to be a done deal as is all the Kyosho Mad Science motors unless Kyosho includes this series again once they restructure. This was the best power per dollar out there.

John and Christo

aeajr

My Feedback: (2)

What battery pack?

What charger?

Sounds like you are happy with performance, but not flying time.

Is this the plane you have?
http://www2.towerhobbies.com/cgi-bin...=LXAWF5**&P=ML

This the battery pack?
http://www2.towerhobbies.com/cgi-bin...?&I=LXBNC4&P=V

With the right charger that pack should be able to be charged in 30 minutes or less at 4 amps.


While I wait for your reply, here are some thoughts.

1) Pick up larger capacity pack
2) Second charger, maybe faster charger depending on the battery packs
3) Lithiums give more time for same weight but are going to cost

Gearbox will likely give you better time on current pack, but adding packs and a charger is easy to do.

For example, on my Aerobird I have 6 packs and 2, sometimes 3 chargers. I never come down.

They bring fuel. You bring packs and chargers.

Some possibilities:
http://cgi.ebay.com/ws/eBayISAPI.dll...974252508&rd=1
Ignore charger for field use - Charge at 4-5 amps

3000 mah 7 cell nimh - $18
http://www.amondotech.com/index.asp?...PROD&ProdID=38

3300s 7 cell - $21
http://www.amondotech.com/index.asp?...ROD&ProdID=533

aeajr

My Feedback: (2)

Chargers

Dymond 1-12 Cell DC/DC Booster Charger $55
DC Charger - Fast and trickle charge of 1-12 cell
NiCad and NiMh batteries Adjustable 0.3-4.2 amp
http://radicalrc.secure-mall.com/sho...57&cart=314724

Triton Charger - $130 - This one showed up under the Christmas Tree - :-)
It handles up to 24 cells NICD/NIMH cells or 4 cell
Lithium cell packs as well as Lead/acid field box batteries.
It will also cycle battery packs which my others will not do. So far I am
very happy with it.
http://www2.towerhobbies.com/cgi-bin...&I=LXCJG7&P=ML
Reviews
http://www.rcbatteryclinic.com/triton.htm
http://forums.radiocontrolzone.com/p...d.php?t=135705
http://www.rcuniverse.com/product_gu...product_id=19\

naveed

Good morning everyone,
I feel happy to have started recieving response on my post, actually I had given up all hopes. Yes I have the hobbico superstar EP the same one you have guessed but with four channels and the stock battery pack.I recently purchased another pack comprising sanyo cells rated at 1800mah. Unfortunatly being new to this hobby I got the towerhobbies recommended charger which can only charge 6 or 7 Nicd cells :-
http://www2.towerhobbies.com/cgi-bin...?&I=LXJC34&P=M
As you have suggested I am happy with the plane though I am still learning to fly but the problem remains the flying time. Two short successive flights can be quick on two packs but there after there is a problem....I have to let the used pack cool down for a while then put it on discharge for a few minutes as per the instructions on the charger and then charge it for 45 minutes or so. I have no plans for Lipos yet.
Right ...so I must have another pack of capacity upto 3300mah and another charger for Nimh.But what about motor, it still arcs and jerks the servos ? Should I get another DD motor like graupner 3301 or greatplanes S-600gd motor and gear combo as I understad Kyosho motors are no more available?
I will be happy I some one could tell me a list of sold recommendations with regards to motor/gear,propeller and any essential accessories so that I can tell my friend to bring the same for me without any more research.
Here in Pakistan the RC sport is not that common with limited hobby shops in three major cities only.They too have parts related to gas powered planes ..no electrics.
Regards
naveed

aeajr

My Feedback: (2)

OK, first the charger.

Sorry to say this but you bought a cheap charger and it is part of what is holding you back. It may charge at 5 amps on a 6 cell battery but, based on their chart, it is only charging at about 2.7 amps on a 7 cell pack. Just do the math.

Look at the 1200 mah pack at 7.2V. If you charge this pack at 1.2 amps it will take 1 hour. If you charge it at 3.6 amps it will take 20 minutes. How long is it taking to charge that pack? 19 minutes? You are not getting a 5 amp charge rate. Not even close.

1700 mah pack at 1.7 amps would be 1 hour. 3.4 amps would be 30 minutes. You are charging at about 3.8 amps on this one too. At 8.4V you are charging at about 2 amps MAX.

If you have not had it a long time, return it since it is not charging anywhere near 5 amps.

7.2V 8.4V
Charge Times: 1200mAh 19 min. 29 min.
1500mAh 20 min. 37 min.
1700mAh 24 min. 41 min.

This charges at a 5 Amp rate and is NOT recommended for charging
NiMH batteries. The charge rate is not adjustable on this model.

Your 2100 mah pack, charging at 5 amps should be done in about 30 minutes. Something does not add up. But no matter. It is giving you what is listed here even though it doesn't make sense to me.

So, if you want to fly sooner and longer you need a better charger and I would swtich to NIMH in the process. You buy what you can when you can.

The first thing I would get is a better charger. The one I recommend above is much better than the one you have and will charge NIHM or NICD so you can charge two batteries at once using two chargers, and the new one should charge them faster, probably in half the time.

The, I would get larger NIMH packs, when money is availalbe. I gave you links to batteries above.

As to a motor - You can go high priced brushless but that will be about $150-$250 for that plane as you will need the motor and speed control.

As far as brushed motors.
Reference info page
http://www.electrifly.com/motors/speed600.html

YOu could probably add this gear box and a new prop to your current motor. Then reverse the leads so that it turns in the opposite direction. Your current prop is probably an 8X4 prop.

http://www2.towerhobbies.com/cgi-bin...&I=LXSL79&P=ML $13
With this gear box you should be able to turn a 9X8 or 10X8 prop with the optional 3.1 gearing pinion.

This is probably a better buy since it includes everything, the included motor is reversed and the pinion is already mounted. Includes prop too. - $37 Just swap out what you have. With this gear box you should be able to turn a 9X8 or 10X6 prop with the 3.1 pinion and you will probably draw 10-20% fewer amps which will give you more flight time. Performance will probably be better too.
http://www2.towerhobbies.com/cgi-bin...?&I=LXBRN3&P=7

Here is a third option.

This is the motor system for the Multiplex Magister. $50 including motor, gearbox spinner and prop. Speed 680 motor with gearbox. includes a 12X8 Prop. You will need to see if you have room for the motor and the ground clearence for a prop that big.
http://www2.towerhobbies.com/cgi-bin...&I=LXJCJ6&P=ML

They recommend a 30 amp speed control which is what I think you have.

OK, so now you have options.

Since the planes performance is not an issue, I would go for the geared motor package for $37.

Don't mess with the motor till you feel the lack of performance.

If you are going to continue to fly electric, you will want the two chargers anyway. I have 4. At the field I always have 2 going and sometimes 3. One pack in the plane. One on the charger to "top it up" just before you fly.

Land, swap packs - wait 5 minutes before you fly to let the first pack cool. Then put it on a charger before you go back into the air.

You should not have to wait more than 15 minutes or so between flights. That is chat time, tune time, getting a drink time.

If you get a 4th pack, and run two chargers, you will be flying all day.


I don't like to wait. I like to fly!



Almost all chargers today can do both NICD and NIMH so it did

naveed

Hello Aerjr ,
Had I realized the importance of a good charger being new to the hobby, I would have never asked for the towerhobbies charger.Anyway this is what I have gathered to go ahead with :-
1) A 3300 mah battery pack
2) Quick charger for both type of batteries
3) S-600GD motor / gear combo
4) Spare propellers like 10X6 or may be 11X7. The stock prop is 9X5.5.
I hope above will solve the problem but I am still not clear about the prop size.

Thanks

aeajr

My Feedback: (2)

What battery charger did you get? Have you tried charging your existing packs with it? How long does it take?

Your NICD packs should be able to be charged at 2C, so a 1900 MAh, which is the sames as a 1.9 Ah pack, should be able to be charged at 3.8 amps, for example. 2 X 1.9 = 3.8 and should take about 20-30 minutes to charge at that rate

NIMH packs can normally be charged at 1.5C unless the manufacturer says they can be charged at a higher rate. So if you have a 3300 mah pack, you should be able to charge that at 4.95 amps. 3.3 X 1.5 = 4.95, or 5 amps. It should take about 30-40 minutes to charge.

Break-in and conditioning

I suggest the first 2 times you use the NIMH pack you charge it at about 1 amp, 1/3 C, and let it fully charge. Should take 3-4 hours. If you new charger has a discharge/cycle feature, you can let it do this for you automatically. If not, then use it to break in the brushes on the motor.


It is a common practice to do the intial charges at a lower rate. Seems to help "condition" the battery. Then I suggest 1-2 charges at 3.3 amps, 1C. Fly the plane.

From that point on you can charge it at 1.5C, 5 amps, unless the manufacturer says you can charge it at a higher rate.

You don't have to follow this conditioning procedure, but I find my packs and motors do better this way.

Breaking in the motor

Put the small prop from your plane on the new motor. We want a load on the motor, but a light load. Mount it somewhere so that it won't move. You can do this in the plane, but make sure you leave as much open/cooling air flow as possible. Leave cowling off, battery covers, etc.

Now use your new battery, or one of your old batteries and run the motor at about 1/4 throttle till the ESC cuts off. Make sure that there is plenty of cooling air flowing over the motor and battery.

Do this for two battery packs. It should set the brushes on the motor. Then the motor will run better and the brushes should last longer by "setting" them at this lower power rate.

An even better procedure would be to use 2-3 flashlight batteris with no ESC. Just tape or attach the motor leads to the D size flashlight batteries and let it run till the batteries are drained. Using this lower voltage method is even better for setting the brushes. Let the batteries run till they are dead

Of course you can continue to use your old charger for your NICD packs so you can charge two packs at once.

Finding the right size propeller

First, make sure you have enough ground clearence or you will be breaking props and maybe gearboxes if you hit the prop when you land.

That new motor package comes with a 9X8 Propeller. This is larger (9) and deeper (8) than the prop that came with your plane. Try that first as that should be OK for that motor.

Heat test

Using a freshly charged pack, fly your plane with your present set-up. Fly at full power for 3 minutes, then land. How hot is the motor? How hot is the battery?

Now, change the motor and use the 9X8 prop that came with the package.

Run the same test for 2-3 flights with the new motor and prop.

Is the motor hotter or cooler than you standard motor? Should be similar. Cooler is better.

How does the plane fly with the new motor/prop combination as compared to the original? You may get stronger climbs and longer flights.

Now try it with the 10X6 - How dies it fly? How hot is the motor?

Now try the next prop - How does it fly? How hot is the motor/battery?

If you get the motor or battery too hot, you will damage them. Make sure your cooling air holes are clear. Perhaps there is a way to get more cooling air to the motor compartment if the motor or pack seem to be running hot.

Good luck with the new power package. Let me know how it goes.

naveed

Hello Aeajr,
Thanks for a very informative and comprehensive reply. I wiil give an update when I recieve and install the new motor / drive.The charger I am looking forward to is MRC 959:-
http://www.modelrectifier.com/produc...gers/index.asp
Hope I have made a correct choice.
Bye

aeajr

My Feedback: (2)

I don't have one but I have been advised to avoid that charger for high current charging. I have been told that it does not meet the expected charge rates unless you keep the car running. I beleive it lacks a booster.

I could be mistaken, but I believe you will be disappointed with the charge times. Let me know how it performs for you.