rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 758 ONLINE 20 EVENTS SEARCH REGISTER  START HERE
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]581 viewsPOST REPLY
RC-Direct . HeliDirect . Heli Wholesaler

.
.
e-Electric General Discussion > Crashed Mini Titan on first flight, need help
 
 
Hoosier_Flyer
Heliman
Location: Terre Haute, Indiana

Last night I put the first flight on my new Mini Titan. I've put several "break-in" hover flights through it for set-up purposes but last night was the first forward flight.

All was going very well for the first three minutes when the helicopter seemed to lose almost all power then basically shut off in flight. I seemed to have only limited control and the heli went in from about 50 feet. Damage was limited to boom and skids but this situation is concerning as when I reached the crash site, everything was operating normally. What gives?

Here is the setup:

Stock Mini-Titan, carbon blades
Spektrum DX7 transmitter AR6100 receiver
Hi-tec HS-65mg servos
Ace BLC-40 esc
Thunder Tiger OBL 29/35-10H motor 13t pinion
Thunder Power 2100 15C cont/ 24C burst

I cannot duplicate this on the bench. The battery was far from dead as I was only able to put 800 back into if after this flight.

Any input or ideas would be greatly appreciated.

Brian
08-09-2008 04:26 PM
 
 
Heli 770
Elite Veteran
Location: Lemon Grove, Ca. USA.

Did you check temps?
08-09-2008 05:33 PM
 
 
USNAviationjay
Senior Heliman
Location: Sugar Land Tx USA

sounds like a RX reboot to me.
08-09-2008 06:04 PM
 
 
michael88997
Key Veteran
Location: northern texas, us

did u do a range check?


---------------------------
Performance Plus Rc Field Rep
trex 500, scorpion motor
08-09-2008 06:40 PM
 
 
Hoosier_Flyer
Heliman
Location: Terre Haute, Indiana

The battery was just barely warm, the motor was warm/hot I would say. The model range checked just fine before flight and had been flown much farther away than it was when it shut down. It seems like just before it hit the ground, I had some cyclic control but no throttle.

What do you mean by a RX reboot? This doesn't sound like something that should happen in the normal course of things.

I'd obviously like to get to the bottom of this before I make repairs and put it back up.

Brian
08-09-2008 07:10 PM
 
 
Heli 770
Elite Veteran
Location: Lemon Grove, Ca. USA.

It sounds like the ESC. Shut down.
08-09-2008 07:26 PM
 
 
Hoosier_Flyer
Heliman
Location: Terre Haute, Indiana

So why would the esc shut down and what can I do to prevent it from happening again?
08-09-2008 08:18 PM
 
 
Heli 770
Elite Veteran
Location: Lemon Grove, Ca. USA.

Your batts. may be causing it with only a 15C discharge rate. I would first check belt tension, gears are to tight, and your pitch.
08-09-2008 08:46 PM
 
 
Hoosier_Flyer
Heliman
Location: Terre Haute, Indiana

Belt tension was set towards the loose side and the gears had just a bit of lash. I wouldn't know if it was over-pitched but it seemed correct for the headspeed. It didn't seem to be laboring at all and it had crazy amounts of cyclic authority for the three minutes it flew. It sounds like I may need to get some better batteries. The only other pack I have is an Align 22c but it is slightly puffed and I'm a little uneasy about running it.

This is my first venture into electrics as I've only flown nitro-powered for the past 15 years.

Brian
08-10-2008 02:58 PM
 
 
Heli 770
Elite Veteran
Location: Lemon Grove, Ca. USA.

I think your pack is on it's way out. Get something with a 25C discharge rate or better.
08-10-2008 03:48 PM
 
 
paintball_kidz
Veteran
Location: Surrey, BC Canada

15C...
08-14-2008 03:00 AM
 
 
Flying Tivo
Veteran
Location: Monterrey,NL,Mexico

15C is not enough

at least 25C

Felipe

If life throws at you lemons......Squirt some lemon juice in the eye of your enemy!!!!
08-14-2008 03:08 AM
HOMEPAGE  
 
 
Aox
Senior Heliman
Location: Laguna Beach, CA

The reason 15C isn't enough, is that a 2100 mah battery at 15C is only able to supply you with (2100 x 15) = 31500 ma, or 31.5 amps.

You want to supply at least 40 amps to your motor, or else it'll starve the esc for current. A 2200 x 25C battery will give you 55 amps of continuous current, easily maintaining full current to the ESC's BEC.

Your other option is to add an external BEC that's directly connected to your main battery.

-Aox
08-14-2008 04:55 PM
 
 
Gazzer
Veteran
Location: Hope Valley, UK

Quote 
15C is not enough



Quote 
The reason 15C isn't enough, is that a 2100 mah battery at 15C is only able to supply you with (2100 x 15) = 31500 ma, or 31.5 amps



Statements like this are just plain wrong!!!!

+30A is more than enough for most flying ,excluding the most aggressive 3D and is probably more dependant on the motor being used.

Although relying on temperature of components is not a good substitute for an inflight data logger to check actual current draw, it would seem from your description that your battery may be failing and unable to hold the voltage.

<--Raptor 60--Raptor 50--Mini Titan E325-->
08-20-2008 08:15 PM
 
 
Aox
Senior Heliman
Location: Laguna Beach, CA

Yeah, how could a motor rated for 40 amps and an ESC rated for 40 amps cause a voltage drop on 31 amp pack, especially with TT's stock pitch curves being so power hungry?

How could the pack, which is UNDER SPEC for the BIRD, according to the manufacturer (They recommend their 40A pack, of course) possibly have anything to do with his under voltage situation?

How could a heli, set up the same as hundreds of others, except for the one difference being the pack, NOT perform like a champ with it's under-current situation?

Even if not, maybe it is the battery going south. The motor and esc combo, specced higher than his pack, may have pulled too much current, and damaged the pack.

Additionally, the TP prolite 2100, which is what he's running, is not a new battery, it could be age affecting its performance as well.

The lesson here is, run the right pack for the bird, not the one that will 'get by if you don't push it too hard".

Though, I love how you throw in your little eye rollies and accusations to someone trying to help educate someone. The math I presented was correct, and whatever the issue, bad pack or under spec pack, he needs to replace it.

-Aox
08-20-2008 08:50 PM
 
 
Gazzer
Veteran
Location: Hope Valley, UK

Quote 
Yeah, how could a motor rated for 40 amps and an ESC rated for 40 amps

Motor rated at 40Amp Does that mean current draw IS 40amp

From the original post he was doing some forward flight not stick banging 3D so probably drawing some 25Amps . Could be that tight belts or mesh would push this way up but the original poster doesn't think so.

Quote 
How could a heli, set up the same as hundreds of others, except for the one difference being the pack, NOT perform like a champ with it's under-current situation?

Are you saying that 100's of others are NOT using 15C rated packs ..... I do with no issues! Not 3D just sports flying.I'm sure there are many many others also doing same!

Quote 
Additionally, the TP prolite 2100, which is what he's running, is not a new battery, it could be age affecting its performance as well.

Exactly what I concluded but does not mean 15C packs CANT be used when working properly

Quote 
The lesson here is, run the right pack for the bird, not the one that will 'get by if you don't push it too hard".

The lesson should be not to make sweeping generalised statements that would lead somebody to think that you can't happy fly the E325 on 15C packs. Not everybody has money to throw at the latest and great high C battery packs. Hell it was not that long ago that 15C was the latest and greatest!!

Quote 
Though, I love how you throw in your little eye rollies and accusations to someone trying to help educate someone.

It is frustrating when generalisations are made which do not really help or answer the original posters question and in fact may be missleading

Quote 
The math I presented was correct, and whatever the issue, bad pack or under spec pack, he needs to replace it.

Yes your calcs are correct, never said otherwise but you did not factor in the burst rating for the battery, and yes he does need to replace the battery IF it is faulty . IF it's not, he could be buying a battery he does not really need ......... which is my point exactly

<--Raptor 60--Raptor 50--Mini Titan E325-->
08-20-2008 10:34 PM
 
 
Heli 770
Elite Veteran
Location: Lemon Grove, Ca. USA.

Gazzer
What makes you think Hoosier Flyer only sports fly his Mini Titan?
08-21-2008 12:01 AM
 
 
1ba68c
Heliman
Location: Bethlehem, Pa -USA

Had same issue with stock BEC. Just normal forward flight nothing crazy and wah-la, no power. After a bunch of crashes I switched over to an Align BEC. So far only one crash do to loss of power in 6 months and I beleive I may have caused it.
08-22-2008 01:24 AM
 
 
co_rotorhead
Senior Heliman
Location: Centennial, CO, USA

Quote 
15C is not enough

I am getting about 5 minutes of flight that includes loops, consecutive flips and rolls, inverted hover and a small amount of inverted flight on some fairly old TP 2100, 15C packs. I am using the stock motor and ESC. The batteries have never puffed and are only warm on landing. No, it's not hard 3D, but 15C is definitely adequate.

My $.02.

I never finish anythi
08-22-2008 01:53 AM
 
 
luv2fly2
Heliman
Location: colton ca usa

Hoosier Flyer

Im curious. What are your ESC settings set to?
09-14-2008 11:05 PM
 
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]581 viewsPOST REPLY
3D Heli Depot . JR-Spektrum . Gyro Hobbies

.
.
e-Electric General Discussion > Crashed Mini Titan on first flight, need help
 PRINT TOPIC Advertisers 

Subscribe to This Topic

Wednesday, December 3 - 8:55 pm - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie