rednekk58

Hey There,
Brand new to heli's AND electrics. Intermediate nitro airplane flyer. Started flying new trex last weekend. Problem I'm having is I hover less than a minute the TR gets jittery and I lose power. Gradually not a complete cut. Running an Align 400s motor, align 25 ESC set @ no brake, low timing and medium (65%?) battery protection. The battery is an Align Li-Ion 1900 mAh battery. Just received two Align 1800 mAh Li-Po batteries. On the charger now, which is a Hobbico MKII Quick charge. Max charge for Li-Po's is 1 amp, in case that has anything to do with my problem. Also tried 9, 11, and 13 or 15 pinion. No difference with symptoms. Using an Align head hold gyro set to approx 40%. I think that's all I can tell ya.

Appreciate any help

Norrmannen

That battery does not deliver enough juice with that mah you need around 10C batteries, believe the li-ion is only capable of around 6C if your lucky. Mine doesn't even get off the ground with that battery.
Hope you got the 12C 1800 mahs, they are at least good enough to start with, I use them with the Align charger with good result, but they need the balancing...

Moe3754

My Feedback: (14)

First off I would replace the 25 ESC with a Phoenix 35 the 25 is just barely enough to cover the BEC and with any servo binding you can over load it and have trouble next I would get a quality battery a thunder power 2100 3s is what I use but I have found better batterys than thunder power at a better price at maxamps.com they have a 3s 2250 mah battery for $60.00 which is better than the $80.00 I paid for my thunder power and maxamps uses the same cells as Tanic does in their Tanic packs.Also get a good charger that is reliable I use the Astro Flight 109 Lithium,did have the Triton but the 109 is better charger.Do a search on the Trex and read all the post there are other people that have good advise also already available in the other post.

rednekk58

I know I could look this up, but I gotta get sim time before bed. Does 3s mean 3 cells thus 3.7V x 3 = 11.1V? What is 12C and 6C, discharge rates? Now I'm getting lost.[sm=confused.gif] I paid $68.99 for the 1800 mAh Li-po, hope it's the 12C. One flight tonight on a charge that was 20 hours old (does that make a difference with li-po?) was just under four minutes of hovering. Good , bad, Really stinks, or LOL you idiot you have a long way to go!

ClemenTang

Yikes! My 11.1/1800 only costs $20!

Clement

Moe3754

My Feedback: (14)

Yes it is 3 cell and as for time well I never timed myself I am more interested in learning how to fly than in flight time besides I have three batterys I use so when one is charging I have two to fly with and with the charger I have my charge times is always around a hour so if I have to wait it is not for long.As for how old the charge is I am not for certain but I don't think that LiPo's loose charge like other batterys do so I don't think that is a factor.I really cannot tell you if you are getting maximum use out of those batterys or not I am not that well versed on exactly how they work and if you are getting maximum charge out of the charger you are using.Sorry!!!!

Moe3754

My Feedback: (14)

$20.00 huh!! that is why it is only a marginal battery at best you get what you pay for in Quality and safety![X(]

rednekk58

ClemenTang,
Is your battery a Li-po or Li-ion? I have a $25 1900 mAh Li-ion that came with my combo. Decided I'm going to use it on a RC boat................. as an anchor! Had a second one, just sent it back. Want to trade for some aluminum landing gear The stock has been glued a few times. At least I'm hitting hard right side up!

Moe,
If I get a 35 ESC is there a chance I can burn something out? The amp rating is not like a overload breaker, so I could run a 60 amp with no damage? Checked uot max amps I will get the 2250 mAh also. That will be my third Li-Po plus the Ion pack. My Hobbico MKII charger only charges at 1 amp max. So a 2250 will take around two hours or more. I can do two at a time, but would like a reasonably priced similar charger with a max charge of two amps.
Replaced a gripper on the main rotor this morning. Need more practice in forward flight on the sim.
I know flight times will be effected by to tight a gear mesh also. Longer the flights the faster I'll learn.

Moe3754

My Feedback: (14)

A 35 is all you will need that will cover it nicely and you will have no problem at all as for the charger I would check out Astro Flight 109 but it is a 12 volt charger which means you need a motor cycle battery or a power pack for it I purchased a great power pack for mine off of E-bay I think with shipping and all it was $50.00 and the 109 is around $125.00 you can find it cheaper in other places all you need do is look around.Also if you join the maxamp web site the price of that LiPo will drop from $59.99 to $56.00 and the more you buy from them the better the discount gets.

ClemenTang

...and it's a $20 LiPo!

Clement

rednekk58

OK, Where can I get some $20 batteries?

jamesotron

I got a 2200mAh 3 cell lipo from flying-hobby.com for only US$33. Seems good. Not sure what the discharge rate is, but I will flight test it as soon as my trex is dialed in and let you know how it goes.

ClemenTang

Shenzhen in China.

Clement

tanasit

With your setup, the Align 25 Amp ESC will do just fine because at hovering it will take about 10 Amp and almost 20 Amp at full throttle. I had the same setup with generic lithium pack and when I switched to Thunder Power 2nd generation, I thought I had a new motor in my trex! With 2000 mAh pack, you should get around 10 to 12 minutes if not you have to check: gear mesh, tail belt tightness (too loose but not skip is much better than too tight) and the hovering pitch. You may be hovering at too high pitch at too low head speed and that will reduce the cyclic control and eat up the batt real fast. Put the heat sink on that motor too.
When you get a good batt, you don't need to worry that the Align 25 Amp ESC won't provide enough juice for all the servos but you have to check "all" the ball link fitting that is the known problem for the Trex becasue they are too tight.
The 2000 mAh pack with 10C rating will put out 10 x 2000 mAh = 20 Amp.
So my Kokam 15C 2000 mAh pack will deliver 30 Amp.
Don't skim on the batt pack. Your charger is fine.
Save enough money and get the Lehner 1020/17T together with 35 Amp CC ESC, and you will get the ultimate power combo for the Trex, bar none

rednekk58

Wow! Lotsa good info. Thanks for explaining the "C". For packs I got 2 Align 1800 mah Li-Po. I've seen a difference in those from the Lith. All I'm doing right now is hovering, and that is at about half throttle? stick? I have an Eclipse and I set the throttle and pitch curve as advised on http://www.trextuning.com/ It's the same motor I'm using. I rechecked the mesh yesterday just before going out and busting the rotorhead. I have a Glo Bee tach for my planes, I'll tach the rotor soon as the parts show up. Belt is good too. Just ordered a 2250mah pack from maxamps for about 60 clams. I figure one more pack after that one and another Hobbico MKII charger. that would be four packs, two chargers charging two batteries apiece @ 1000 mah. Should have a pack popping off every half hour Who am I sh*%#@* I spend more time fixin' than flyin'.
I was very careful with the ball links when I assembled it. I read on Trex tuning that was a problem. I made sure everything moved very freely. Then used lite oil. It'll be awhile before I outgrow this motor and ESC. I used the heat sink that came with it. I use an infrared thermometer (point and read) on the battery after flight, and the hottest was around 110 F. Have not measured the motor, but not hot to the touch. Thanks for the advice.

tanasit

One more note: when inserting the ball link, note that one side has larger diameter than the other, so you should insert with the larger size going in first. Unless it is absolute to adjust half a turn for the blade pitch, then you may have to push hard to get a smaller size to go in first.

rednekk58

I didn't know about the link diameter difference. Light bulb just went off. Explains why some are hard to push. Thanx again, anything else you can think of. Bought some wheel collars for the fly bar, I might try that. Was thinking of making training gear from an electricians fish. Made of spring steel. Right now I'm using dowels and plastic golf balls.
Here's a ? What is the Hi, Med, & Lo, battery protection settings in the ESC. I think it's 60, 65, & 70 %?

tanasit

RE: Here's a ? What is the Hi, Med, & Lo, battery protection settings in the ESC. I think it's 60, 65, & 70 %?

I assume you are talking about the "cut off" voltage when the main battery falls below the preset voltage, the power to the motor will be cut, so that you still have the control of the other servos. Initially it was designed for the air plane so you can land safely because you can glide without motor power. As for the heli, it depends on the manufactures of the ESC, for example the CC (Castle Creation) has 6 options for cutoff depending on how many cells and what type of cell. For 3 cell Lipo, it is option 5 which is 9.0V cutoff, which is also for the 12-14 cell NiCd or 12-16 cell NiMH. This turns out to be 81% for Lipo, 57.6% for NiCd and 53.6% for NiMH because both NiCd and NiMH once the power is getting low, it will drop real fast whereas the Lipo can deliver more power at the tail end.

Further more, you can set how the cut off will be: hard cutoff or soft cutoff.

Finally, the current limit which means if an over-current condition detected (moving part got stuck e.g. something get into between the gears), then it will cut off at 5 different options.