Raptor 50 gear ratio  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> RC Helicopters >> Thunder Tiger - Raptor 30, 50, 60, 90 >> Raptor 50 gear ratio
Page: [1]

Login
Message << Older Topic   Newer Topic >>
Raptor 50 gear ratio - 6/12/2002 10:15:01 AM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		I either read or heard somewhere that TT is now not recommending changing the gearing on the Raptor 50 upgrade from the standard, 9.56:1, to the 8.5:1 gearing that is included with the upgrade.
I don't understand why when changing to the 8.5:1 would put the engine in 12k to 15k range, depending on what headspeed you like, it should be at more it's peak torque, and run much happier, and last longer.
At a headspeed of 1600 it would be turning 13,600 instead of 15,296, which should make it a lot happier.
Just out of curiosity, what headspeed are most of you guys running on the Raptor 30/50?
       Post #: 1

Raptor 50 gear ratio - 6/12/2002 6:01:09 PM   
Furyflyer2



Posts: 2647
Joined: 6/8/2002
From: middlesex, NJ, USA
Status: offline 		The OS 50 peak Hp is @ 17,000 rpm. With the stock gearing you will have to run a 1778 to hit the peak hp of the engine. With the 8.5 gearing you have to run a 2000 head speed. I opt to run the stock gearing @ 1750 verse a 2000 head speed.


_____________________________

Paul G,
www.3dxhobbies.com

(in reply to flynfool)
       Post #: 2

Raptor 50 gear ratio - 6/12/2002 8:00:43 PM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		It is my understanding that you should be looking for the peak torque not peak hp. Is this not true for heli's?
If you aren't using the 8.5 gearing would you like to get rid of it?

(in reply to flynfool)
       Post #: 3

Re: Raptor 50 gear ratio - 6/12/2002 10:07:21 PM   
Furyflyer2



Posts: 2647
Joined: 6/8/2002
From: middlesex, NJ, USA
Status: offline 		[QUOTE]Originally posted by flynfool
It is my understanding that you should be looking for the peak torque not peak hp. Is this not true for heli's?
If you aren't using the 8.5 gearing would you like to get rid of it? [/QUOTE]

No , you want peak HP @ a given rpm ( you'll find peak torque their also). The OS 50 makes is peak hp @ 17,000 any higher rpm the power curve goes in the toilet e.i. no power. Optimal setup up is to keep a constant rpm , with in it's power curve that's why tune pipes work so well their tuned to produce engines peak out put @ a correct rpm.


_____________________________

Paul G,
www.3dxhobbies.com

(in reply to flynfool)
       Post #: 4

Raptor 50 Gearing - 6/13/2002 10:09:59 AM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		Mr. FuryFlyer2, I respectfully disagree. After many years of reading Clarence Lee's column in RCM, I know for a fact that the peak torque occurs well before you reach the peak hp, and it in fact actually falls off as you approach peak hp rpm. Curtis used to run V-tech pipes because he said they increased the mid range torque. I strongly suspect that his muscle pipes do the same as they closely resemble V-tech's.
respectfully,
Carl

(in reply to flynfool)
       Post #: 5

Raptor 50 gear ratio - 6/13/2002 7:05:41 PM   
Furyflyer2



Posts: 2647
Joined: 6/8/2002
From: middlesex, NJ, USA
Status: offline 		To truthfully answer the question we need a dyno of the OS 50 with out that it is speculation. Either way a engine produces it peak hp @ a given rpm any thing over that you get a power drop off. I run a MP pipe and that pipe develops it's peak power between 1750-1800 ie with a 9.3:1 gearing that makes the engine rpm 16,275 +/- ( OS 61WC develops it peak hp @ 16,000 rpm)any thing over the rpm range the power falls right off. Theirs some proof of running a engine within it's practical peak rpm range.


_____________________________

Paul G,
www.3dxhobbies.com

(in reply to flynfool)
       Post #: 6

Raptor 50 gear ratio - 6/14/2002 3:36:53 AM   
Hitch-Hiker



Posts: 273
Joined: 12/27/2001
From: New Middletown, OH, USA
Status: offline 		Flynfool,

I am flyin' abot 1900 rpm with 8.5:1 gearing with a GV-1 in my Rap50. This OS50 makes tons of torque with this power to weight ratio. I also am sticking with the stock 50 muffler on my machines because the heli likes the broad power in both the midrange and high end.

Some guys at our field, are flying same OS50 engine with the Curtis 60MP. This actually gave better fuel economy, but I didn't like it because the engine lost some of its midrange power, but did gain on the high end.

With my flying 3D style, I am constantly loading and unloading the heli, the muffler dosn't let the engine lean as much when you unload the head and it is only needing 50% throttle to maintain the 1900.

The stock gearing for the os32 or the tt36 would be asking the 50 sized engines to operate far above their happy rpm levels.

I guess that if you like to fly at 1600 head speed, this would be OK for the 50 and stock gearing. But why would you need to have that much power without the rotor speed to use it? The engine would be happier at the lower rpm and would also be using alot less fuel.

Jeff Swartz

(in reply to flynfool)
       Post #: 7

Hitch-Hiker - 6/14/2002 9:57:53 AM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		You mean your OS 50 is turning 16,150rpm's at 50% throttle? or 50% stick? What blades are you running?
Thanks for your input,
Carl

(in reply to flynfool)
       Post #: 8

Raptor 50 gear ratio - 6/14/2002 7:13:45 PM   
Hitch-Hiker



Posts: 273
Joined: 12/27/2001
From: New Middletown, OH, USA
Status: offline 		My setup:

Normal mode - 1600 rpm head speed, govoner is on, 8.5:1 = 13,600 engine rpm. I use this only at my first lift off and some slow down hovering.

Idle 1 - 1850 rpm head - not used much...

Idle 2 - 1900 rpm head 16,150 engine rpm - sometimes I will bump up to 1950-2000 head rpm but its generally not needed.

This engine is rated to run between 2,000 and 20,000 rpm with is optimum performance being 17,000 rpm (this would be a head speed of 2000 rpm)

Amount of throttle needed for 1900 head rpm is always changing depending what you are asking of the heli. Pitch curves do work well for alot of flying but not all 3D. Simple example: Inverted and climbing with stick position at 20% giving 75% throttle is fine for a normal throttle curve, but what if... you are right side up and wanting to drop altitude 20% stick position and still giving 75% throttle would over rev the heck out it. This is why I run the govoner, throttle is no longer hindered by the stick position. In this case, it may back clear off to 25% throttle. I also stay with the muffler to keep a wider power range.

Hope this helps! I would stay with the 8.5:1 ratio for the TT50 or the OS50.

Jeff Swartz

(in reply to flynfool)
       Post #: 9

Raptor 50 gear ratio - 6/14/2002 7:15:10 PM   
Hitch-Hiker



Posts: 273
Joined: 12/27/2001
From: New Middletown, OH, USA
Status: offline 		Carl,

I am running 600mm zig-saw blades. I think they are awesome!!

Jeff

(in reply to flynfool)
       Post #: 10

Hitch-Hiker - 6/14/2002 9:35:46 PM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		Thanks for the input. I am just trying to see what most people are using on the Raptor.
I'm not positive on this, but I believe TT is not recomending headspeeds above 1900 with the 600mm blades, you might want to check. Something about the added weight fatiguing the blade grips, if I remember correctly.
I have a 30 (tt36), and a 50 (os50), the 50 had a pipe on it when I got it, but I got a muffler on it now because I didn't like the pipe and it really didn't need it. The power to weight of the 50, in my estimation exceeds a 60 size machine. Unless of course you drop a 90 in it,lol.
The reason I'm trying to see what others are running is the 50 has stock gearing in it when I got it and I'm contemplating buying the 8.5 gears.
Is it hard to change the pinion?
Thanks,
Carl

< Message edited by flynfool -- Jun 14 2002 4:41PM >

(in reply to flynfool)
       Post #: 11

Raptor 50 gear ratio - 6/15/2002 6:51:27 AM   
Hitch-Hiker



Posts: 273
Joined: 12/27/2001
From: New Middletown, OH, USA
Status: offline 		Carl,

Everything is easy to change on the raptors 30/50's

Most blades are not rated above 2000 rpm.

I was with Greg Sawyer from ACE last weekend at MD and he did not mention anything about the 1900 rpm... That will be good question for the raptor boards. I would think that another factor would be the weight of the blades. My Zig-saws are very light, only about 115 grams. Heavier blades would give more of a load to the head!

Jeff S.

(in reply to flynfool)
       Post #: 12

Hitch-Hiker - 6/15/2002 9:24:47 AM   
flynfool


 

Posts: 40
Joined: 2/18/2002
From: Lufkin, TX, USA
Status: offline 		Jeff,
What Raptor boards? Your right, the weight of the blades is really the factor. WOW, those blades are light! Is that a special or are all their 600mm for the Raptor that light? I'm presently in the process of rebuilding the 30. Last Sunday the ground inadvertently interrupted my flight path,LOL. A friend of mine who is thinking of getting one was amazed that it wasn't totally destroyed. It's really not bad, I managed to get it flat before it hit and was able to go to throttle hold so it didn't beat it'self to death,lol.
Thanks for your input,
Carl

(in reply to flynfool)
       Post #: 13

Raptor 50 gear ratio - 6/15/2002 6:07:27 PM   
Hitch-Hiker



Posts: 273
Joined: 12/27/2001
From: New Middletown, OH, USA
Status: offline 		There are two good raptor boards, heres the links.

http://www.topica.com join the raptorheli list
http://www.acehobby.com They have their own forum set up.

Zig-Saw 600mm are standard that light... AND these are the best autoing blades I have ever flown...

Raptors are pretty darn durable.. I folded the blades back with an inverted rolling auto and it literally fell 300 feet to the ground. Picked it up, bent the boom straight with my knee and finished the flight

Jeff S.

(in reply to flynfool)
       Post #: 14

Page:   [1]
All Forums >> RC Helicopters >> Thunder Tiger - Raptor 30, 50, 60, 90 >> Raptor 50 gear ratio
Page: [1]





Jump to: