rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 256 ONLINE 20 EVENTS SEARCH REGISTER  START HERE
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]655 viewsPOST REPLY
CanoMod . Futaba-RC . A Main Hobbies

.
.
Century Hawk - Falcon - Raven - Predator > Running out of options here, Raven just does not have power
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

Hi everyone
You may have been following the Raven bogs inverted thread. Well, i think i got them similar but I am at the point were i just don't know why this bird has poor power/pop. In realflight, i have to turn the torque generator setting on the Dolphin 46 down to 45 from 100 to get remotley similar flight characteristics. It just doesn't seem to move the way i want it. Maybe it is the hot temperatures out but i am getting sick of this. When i go to full collective the heli sort pulls out, nothing impressive. Not remotley close to other 50's i have seen. Do you think my hyper has met its end. I have tried 2 different pipes, mp5 and hatori, tried all sorts of different throttle curves, have the grey speed up gear. What could i be missing here. Would slow cyclic servos make the illusion that this bird doesn't have power? I am starting to think that could be it.
08-01-2008 04:47 PM
 
 
az_heliguy
Senior Heliman
Location: Florence, AZ

what servos are you running? what is the transit speed? could be an issue where they may be going bad, who knows... if you have your pitch curve set right +/-10 (+/-12 in my case), you shouldnt notice any difference normal or inverted. a buddy of mine converted his hawk pro to a 50 size and his collective went to complete crap, was not snappy at all. replaced the collective servo to a 9252 and it works great now. perhaps yours are at the end of thier life cycle, or just too slow...
08-01-2008 05:43 PM
HOMEPAGE  
 
 
oldfart
Elite Veteran
Location: Vancouver, Canada

Have you checked to insure that your fan has not come loose and is robbing power and cooling ability, by dragging up against the top of the fan shroud?
08-01-2008 06:12 PM
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

Old fart
The fan is in good shape. I am really curious about these servos

s3050 on 4.8v .20 and 70oz torque
08-01-2008 06:47 PM
 
 
oldfart
Elite Veteran
Location: Vancouver, Canada

When you say "does not have power inverted" do you mean that the rotor speed bogs or that it just does not climb inverted as well as it does right side up?
08-01-2008 07:29 PM
 
 
az_heliguy
Senior Heliman
Location: Florence, AZ

your gonna want something faster then those cambo... i first used ds821's on my raven and changed them out because i didnt think they were fast enough and they are listed as .15 @ 6v. if you got .20 at 4.8v that may be a reason why you think your losing power... they are just slower to react to your input. go in your sim and put the torqu generator back to where is was and change all your collective and cyclic servo transit speeds to .20 and then try the sim...
08-01-2008 07:29 PM
HOMEPAGE  
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

That is exactly the first thing i did AZ heli guy. Even with .2 the heli could still power through stuff without a problem. Maybe it is me, i don't know but it is just really frusturating. Tictocs, wich i can do all day long in the sim are impossible. I don't think the sim predicts inflight load. I am worried that increase loads in flight are slowing my servos to the point were they just can't transition to other menuevers without maxing out the cyclic to get the heli to do what i want?

Inverted, the heli just doesn't seem to have as much pop as upright although better than before.

This is what i am going to do.

I am going to lower my pitch range (don't trust my pitch gauge) to the point were the blade actually speeds when i go full cyclic. This way, i know when i have gone to far. Maybe i have to much collective range still.
08-01-2008 08:27 PM
 
 
oldfart
Elite Veteran
Location: Vancouver, Canada

What governor are you using?

If you are not, be sure to mix in a good bit of Aileron to Throttle and elevator to throttle (usually needs a fair bit more elevator to throttle mix then aileron to throtle mixing).
08-01-2008 08:51 PM
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

No gov

cyclic to throttle mixing is about 25% throttle for full cyclic stick imput
08-01-2008 08:52 PM
 
 
Ray Fernandez
Elite Veteran
Location: Guam (U.S.A.)

I don't know if I missed it, but how old and how much flying time on your engine?

Ray Fernandez - GUAM
08-01-2008 09:51 PM
 
 
oldfart
Elite Veteran
Location: Vancouver, Canada

I would aso definitely add more mixing ... try 40 or 50...may even require more, depending on your set-up
08-01-2008 09:54 PM
 
 
Jafa
Elite Veteran
Location: Sydney, Australia

No governor on a 50?
I've found it hard to use a 50 without a governor
I had to use a U curve 100 60 50 60 100 to avoid over speeding
That left me with not enough power to do high load stuff

The cyclic to pitch mixing has problems
Many radios don't limit the throttle servo throw
to the ATV value you set - the mixing over drives it
This means your throttle servo binds and could burn out
And do a full negative collective descent without a governor
the engine will rev it's guts out and the head will overspeed

Get a governor on that bird - it will provide much more usable power

What headspeed are you running in idle up? Aim for 2000

What blades are you using?
I used a set of NHP 600's on a Sceadu for six months
I also struggled with poor climb rates
I switched to RotorTech 610's and the problem was solved

Remember that people are running up to
+/- 14 degrees pitch on the Trex600N
It seems to take it well

Does your heli climb straight when upright?
If not, that will be robbing you of collective power
Both blades need to be pulling hard and the same
If the climb pulls to one side you need to fix it

Then you need to ensure that at 0 pitch
the bell mixers on the seasaw are level
Otherwise they different a different pitch change rate
between going + and - which could also be part of your problem

Make sure the flybar is level when checking this all out

When setting up at 0 pitch
use a 0 50 50 50 100 pitch curve
This means you wont have a small error from stick position


Lepton | TRex600Nitro | Sceadu | Freya | Avant | Predator Carbon Max
08-02-2008 02:43 AM
 
 
RICH.L
Key Veteran
Location: east springfield p.a.

At 2000 for headspeed with the grey speed up gear that thing should be running super!!

I know you said you replaced the bearings in the engine,but when you put the head back on did you make sure you evenly torqued the bolts in a criss/cross pattern?

I speak from experience on this one,I replaced the bearings on my hyper and after that my raven had poor power and would not climb as well as I thought it should.

When I pulled the engine back out I had found the piston was riding up against the cylinder wall and you could see where the ring was shiny,I put a new ring in it and scuffed up the cylinder with fine sandaper using tri-flow and then torqued the head properly.I did not torque the head the proper way)

After that the ring ran awesome until I decided to do something really stupid and sell it for a 90 series heli(one of the dumber things I have done)

rich
08-02-2008 12:40 PM
 
 
RICH.L
Key Veteran
Location: east springfield p.a.

Here is a link with pictures,it's worth reading cambo!!
just trying to help out.

And just curious how many people came back to century after trying some other heli's out there?

The raven looks pretty tempting again for only $299.00!!

http://www.runryder.com/helicopter/t263160p1/

rich
08-02-2008 12:47 PM
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

Hi everyone,
I made sure to setup the radio so it doesn't over drive the servo. I have spent alot of time getting this head setup right and am convinced it is. I am using the stock blades but in other vids with the stock blades the heli has loads of power.

Now, what is weird is my middle throttle setting in idle 2 is nearly 70% throttle on the barrel and the head is NOT over speeding. As a matter of fact, i feel like i could got even higher and not over speed the head. My throttle curve at one point was 100-90-70-90-100 and i was not over speeding the head but as you can see, throttle was kind off maxed out. Maybe Rich i should go with your advice and grab a new ring and piston.

Engine has 7 gallons BTW


Cameron
08-02-2008 04:31 PM
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

I just ordered a new ring. I was doing some searches and am almost positive that my ring was bad. The ring had a VERY large gap in it and the engine has very low compression.
08-03-2008 01:31 AM
 
 
az_heliguy
Senior Heliman
Location: Florence, AZ

well, a large gap between the piston ring and sleeve could definately be an issue, but i dont think that would explain why it only seems to loose power when inverted. the gap would affect the engine performance as a whole, not just in certain orientations... (at least one would think so, lol...)
08-03-2008 02:42 AM
HOMEPAGE  
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

az heli guy, removing the header tank resolved my inverted power loss problems. The problem there was mainly the HS not recovering at all once inverted.

Currently, what is happening is the HS just can't maintain when transitioning from one trick to another. Here is an example of what is happening. This is what it is like trying to do a tic toc. I pop the stick and see really poor climb out, the HS slows. I pull back on the cyclic, not all the way of course, but at the same time move the collective to 0 to try and avoid putting to much pitch on the head. (I have been practicing this allot on real flight so i am not over doing it ). The HS slows more. Once on the inverted side i would guess i have lost anywhere from 300-500 rpm as the tail has trouble holding. My HS is slow enough that i might, if i am lucky, be able to bounce back but after that the heli falls like a rock and i have to put the pitch back to zero again for the HS to recover. Essentially what has happened is i can't do more than one flip, roll, or whatever without having to stop and let the HS recover.
08-03-2008 04:20 AM
 
 
Cambo
Senior Heliman
Location: Phoenix, Arizona

Hmmmm, a few concerns after opening up the engine. First off, Rich.L, my engine looks alot like yours. There is definate wear on the exhaust side and it is obvious after opening up the engine that the piston was riding the liner on the exhaust side . The ring, strangley, doesn't seem to lock from that little tiny pin in the piston. How big is that suposed to be? Not sure if it broke off or not. Also, if I put the piston in the liner and rotate it, the ring will not rotate with the piston. Is that bad?
08-03-2008 10:14 PM
 
 
az_heliguy
Senior Heliman
Location: Florence, AZ

cambo...

can you post pics of your engine and what your seeing?
08-03-2008 10:26 PM
HOMEPAGE  
 
 
2 pages [ <<    <    ( 1 )     2     NEXT    >> ]655 viewsPOST REPLY
Boca Bearings . Modefo's RC Helicopters . XHELI.COM

.
.
Century Hawk - Falcon - Raven - Predator > Running out of options here, Raven just does not have power
 PRINT TOPIC Advertisers 

Subscribe to This Topic

Saturday, November 22 - 10:27 am - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie