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E-flite . Next D . Fast Lad Performance

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e-JR Voyager E > can't get higher than 3 feet hover
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

Just got my VE (used) and have an experienced Heli pilot helping me out. We got everything setup and went to fly. He couldn't get it over 3 feet even at full throttle and 10 degree of pitch.

Here is the current setup:

Stock motor/esc (10 degree timing - new brushes, broken in)
JR G400
Jr 341 servos
stock blades
8 cell battery pack (4/5 SC size - lighter than normal gp3300's).
15 tooth pinion.
Futaba 7C radio

We have the pitch curve at 5 degree at mid stick with the throttle curve up to 74% at midstick.

Can anyone help out?

I will evetually go to a brushless but right now I am sticking with a brushed motor until I learn how to fly.
03-13-2004 Over year old.
 
 
pepper
Veteran
Location: GREAT STATE OF TEXAS!!

what is your head speed??
03-13-2004 Over year old.
HOMEPAGE  
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

how do I figure that out. With a tach? Or is there a calculation?

I can get it, I just need to know how.
03-13-2004 Over year old.
 
 
pepper
Veteran
Location: GREAT STATE OF TEXAS!!

that is about the best way.. not sure of any other way.. may want to check and make sure that the batteries are fully charged,, my sound like a stupid answer but you never know.
03-13-2004 Over year old.
HOMEPAGE  
 
 
Voyager
Senior Heliman
Location: Canada

Your head speed is probably low.
You may have too much pitch for not enough throttle.
My throttle curve hits max by the time I am at mid stick (hover).

... Rob
03-13-2004 Over year old.
HOMEPAGE  
 
 
Ralphw
Key Veteran
Location: Spring, TX

With the stock motor you ought to have at least 90% - 95% throttle at mid-stick. I might also look at the possiblity of a 16t pinion (no bigger than that with the stock motor).

Mine flew well with the book value curves and 90% throttle.

Ralph W.
"Life's Short, Fly Fast"
03-13-2004 Over year old.
HOMEPAGE  
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

Seem like the common problem here is low head speed.

Here is question:

Head speed is going to be based on relative resistance (i.e. pitch). So at what pitch do you measure the head speed? zero?

I can actually hear the rpm's picking up as I start back down from full pitch to half pitch.
03-13-2004 Over year old.
 
 
pepper
Veteran
Location: GREAT STATE OF TEXAS!!

I can actually hear the rpm's picking up as I start back down from full pitch to half pitch.



that would indicate that you have to much pitch. also is still sounding like your head speed is to low..


pepper
03-14-2004 Over year old.
HOMEPAGE  
 
 
Ralphw
Key Veteran
Location: Spring, TX

If you can hear the rpm decrease as you increase the pitch, you are probably asking too much pitch from the drive train. I'd try increasing the throttle percentage first and see if that helps. If it still sags with pitch increase, bring down the pitch curve values a bit.

I measure pitch in flight at hover. This gives me a consistant load on the system. I wouldn't want anything less than 1450-1500 rpm at hover with the VE. Get below the 1400 mark and you are on the verge of the "wobbles".

Ralph W.
"Life's Short, Fly Fast"
03-14-2004 Over year old.
HOMEPAGE  
 
 
twguns
Senior Heliman
Location: Indianapolis, IN

The problem is likely your choice of batteries... I just went through this with a new guy here in Indy...

Do you know exactly which cells are in your battery pack?? If they are the 2150's, they have an IR (internal resistance) of about 25mohm and won't allow enough current to supply the needs of your motor...

Go with any of the sub-c batteries as most will have an IR of less than 6 mohm (the lower the better) and these will fly your model just fine...

The model will fly just fine with the extra weight, but more power, from the larger batteries...

I find the Nimh cells in the 3000 to 3300 ma capacity to work the best these days... Another good cell is the Sanyo 2600's...

Sanyo, Gold Peak (GP), Panasonic, and Saft all have batteries in this range that work well...

bigTim
03-14-2004 Over year old.
HOMEPAGE  
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

OK, it 's starting to make more sense now.

What should pitch be for this heli at hover(midstick) with stock motor/esc and 8cells?
03-14-2004 Over year old.
 
 
Ralphw
Key Veteran
Location: Spring, TX

Nice catch bigTim, I completely missed the cell size in the first post (I probably still would not have thought of it..even if I'd noticed ).

Rodney...the book calls for 7-8 degrees, but thats with only 80% throttle. I'd up the throttle value to at least 90 and probably 95% then use 5-6 degrees to start with. BTW, I have two 8 cell packs (1 2600 NiMH and 1 2400 NiCD) left from pre li-po days. If you're interested, PM me.

Ralph W.
"Life's Short, Fly Fast"
03-14-2004 Over year old.
HOMEPAGE  
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

ok. I have been able to try some things.

First, I up the throttle to 95% at midstick.

My head speed at mid stick is around 1470-1500 RPM (as measured by a tach)

It gets light on its feet but cannot get it to come off the ground gracefully.

It may very be the batteries. They are some 4/5 SC from Cheapbatterypacks.com. They are brand new and only have 1 to 2 cycles on them. I unfortunatley don't have a charger/discharger that can do 8cell packs or I would get the voltage and IR info.

I am getting ready to head to the Hobbyshop and grab a pitch guage to verify the settings (the expert pilot originally set it up).

A quick question: Will a brushless setup correct this problem still using my 8cell packs I have currently. Something like a c40-8L and appropriate ESC.
03-14-2004 Over year old.
 
 
KnimRod
Senior Heliman
Location: Central Michigan

A brushless would probably fare a little better but it does sound like your pack is junk.

Do yourself a favor and contact Steve or Sarah at www.battlepack.com for a pack of GP3300 cells. $47. for an 8-cell pack with your choice of connectors and the cells will be soldered, not welded. You won't regret it.

Lance
03-14-2004 Over year old.
HOMEPAGE  
 
 
twguns
Senior Heliman
Location: Indianapolis, IN

Lance is correct... Get a quality battery pack and you will be fine...

A charger won't give you the IR info. It would come from the manufacturer of the individual cells...

bigTim
03-14-2004 Over year old.
HOMEPAGE  
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

FIXED MY PROBLEM

It wasn't the batteries.

I had the wrong timing in the motor. I was around 10 degree retarded.
Once I corrected that, everything is working much better now.
03-18-2004 Over year old.
 
 
DeanM
Senior Heliman
Location: Oklahoma City, OK

How does one adjust the timing on the stock motor? ... I suspect I should check/adjust mine.

Dean
03-18-2004 Over year old.
 
 
rodneybarrett
Heliman
Location: Brentwood, TN USA

Dean,

There should be a line on the actual can (near where the endbell will go). There should also a a thin line on the endbell. those two lines need to match up.
03-18-2004 Over year old.
 
 
DeanM
Senior Heliman
Location: Oklahoma City, OK

Thanks ! ... Dean
03-18-2004 Over year old.
 
 
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e-JR Voyager E > can't get higher than 3 feet hover
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