Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Other Makes and Models Helicopters > Quick of Japan


Quick of Japan QJ Helicopters


Reply
 
Thread Tools Display Modes
Old 02-28-2010, 05:28 PM   #1
PAS
Registered Users
 
Posts: 153
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default EP8 wags its tail - Any ideas?

From day 1, My EP8 has had a tail wag I can not tame.
First off, a basic question: Does the EP8 use leading or trailing edge control on the tail?
I have tried both with leading edge control seeming to work better.

My equipment and details:
Radio is a DX7 with Gyro gain on GEAR channel.
Gyro is a GY401 - Delay=0, Travel just under 100
Very little drift in gain mode so centering does not seem to be a problem.
Tail servo is a Hyperion - DS13ACB
The GY401 is in digital mode (tried both modes with no difference noticed)
The tail wags in both heading hold and rate modes..
Setting the gyro gain on the DX7 to +30 (heading hold mode) cuts back on the wag but it is still present.
More gain = more aggravated wag.

Head seems a bit tight but seems vibration free once spun up.
Heli has never been crashed.

Thanks for any advice!
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-01-2010, 12:10 AM   #2
Henry
Registered Users
 
Posts: 612
 
My HF Map location
Join Date: Aug 2005
Location: Rockville, Maryland
Default

I had a similar problem early on while hovering and determined that my head speed was too low. What is your head speed?

Leading edge control is best for the 8's tail rotor.
Henry is offline        Reply With Quote
Old 03-01-2010, 11:16 PM   #3
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

Thank you Henry, I think you may be correct.
I don't have a tach but using the head speed calculator, I think I am only running about 1600 RPM in hover (not in idle up).
I believe that is too slow and something more like 1800-1900 is desired.
Do you agree?
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-01-2010, 11:33 PM   #4
Henry
Registered Users
 
Posts: 612
 
My HF Map location
Join Date: Aug 2005
Location: Rockville, Maryland
Default

Absolutely. 1600 is where I was experiencing the wag. Another couple hundred rpm should wipe it out! Let us know how you get along...
Henry is offline        Reply With Quote
Old 03-01-2010, 11:37 PM   #5
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

Thanks again Henry. I will post an update once I get to fly again.
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-02-2010, 08:44 PM   #6
quickfighter
Registered Users
 

Join Date: Jan 2010
Location: Marshville N.C.
Default

Paul, I have had to fix that problem before. What I do is first I make sure the complete linkage is working freely. I unhook the linkage at the servo arm, and i take my fingers and move if just a little bit back and forth. It should move very freely and not bind at any point. If it does not move freely, I unhook the plastic links from the balls. Now move the linkage, and find any part that does not move freely. Use only thin 3in1 machine oil or such on the t/r shaft. Then I snap one of the links back on. If it does not work freely, either buy one of those tools to make it a little bigger or take a pivot ball and mark it up with a set of pliers and put it in an electric drill and turn it very slowly and put the link on it and move it around so to enlarge the inside, Only just a little bit.
Your t/r blades should pivot with just a little resistance in the blade grips. Make them both feel the same. They have to be free to lead and lag at the different speeds of the rotor.

Harold
quickfighter is offline        Reply With Quote
Old 03-02-2010, 11:41 PM   #7
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

Harold, thank you for the great advice. Once I get a chance, I will carefully check the operation of the tail and also increase the head speed as Henry suggested. The EP8 went together very easily but the ball links are a bit tight but not to the point where I knew I had to use the link sizer. I figured after a few flights it would loosen up a bit.
I will report back and hope to snap a picture as we need "Show me your QJ thread".
Thanks!
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-03-2010, 08:26 AM   #8
quickfighter
Registered Users
 

Join Date: Jan 2010
Location: Marshville N.C.
Default

That's good. We will get it right, one way or the other. If it does not work freely, make you a reemer tool out of a pivot ball and just use it a very little at the time, moving it all directions as you turn the drill on slow.

Harold
quickfighter is offline        Reply With Quote
Old 03-04-2010, 11:09 PM   #9
Henry
Registered Users
 
Posts: 612
 
My HF Map location
Join Date: Aug 2005
Location: Rockville, Maryland
Default

Hey PAS, how's your progress?
Henry is offline        Reply With Quote
Old 03-04-2010, 11:15 PM   #10
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

Thanks for asking Henry but unfortunately I work 10-12 hours a day.
Add the family to that and my R/C time is very limited.
I hope to get some time in this weekend.
I was thinking that I should probably get a new pinion to speed up the head a bit.
The motor shaft if 5mm and I currently use a 12 tooth and think I should go to 13.
Do you know the where I can get the correct pinion to mesh with the EP8 main?
Thanks!
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-04-2010, 11:43 PM   #11
Henry
Registered Users
 
Posts: 612
 
My HF Map location
Join Date: Aug 2005
Location: Rockville, Maryland
Default

Contact Charles at Helicopter Hobbies. He should have some on hand. You might want to consider a 14-17 tooth gears. I'm happy with the 17 tooth...
Henry is offline        Reply With Quote
Old 03-06-2010, 03:16 PM   #12
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

Thank you Henry and Harold, you made my day!

First, I increased the head speed to approximately 1900 RPM but still had some tail wag.
I decided to give the tail another look over as Harold advised.
Everything seemed smooth but the ball links attached to the tail grips were a on the tight side.
Using the ball link sizer a did just a couple of turns on each link and they did snap on a little easier.
To my amazement, the wag DISAPPEARED!!!
I was able to crank the gyro gain way up with absolutely no tail wag!!

As far as getting another pinion, I don't think I should go more than a 13 tooth.
I am running 6 cells with a 1030Kv motor (85% efficient) which gives a maximum head speed of 2206 RPM.
According to the head speed calculator, I will exceed 2400 RPM (2574 RPM) on a full battery if I go to a 14 tooth pinion.
For now a 12 tooth will probably be fine as long as I keep the throttle @ 80% or better.
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-06-2010, 03:41 PM   #13
Henry
Registered Users
 
Posts: 612
 
My HF Map location
Join Date: Aug 2005
Location: Rockville, Maryland
Default

Glad to hear you got tit gone! Hope you are using carbon fiber blades!
Henry is offline        Reply With Quote
Old 03-06-2010, 08:36 PM   #14
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

I have both wood and carbon fiber (just purchased from Charles).
I was hoping wood blades would be OK to about 2000RPM.
Do you think I am pushing it?
-Paul
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Old 03-08-2010, 08:02 AM   #15
quickfighter
Registered Users
 

Join Date: Jan 2010
Location: Marshville N.C.
Default

Good work guys! If you tail rotor ever moves or jumps around, check the tension of the tail belt.
If it is the 400mm wood blades for the EP8 from Japan, you do not have to worry, i have seen them run 2200 for years and we never had one to destroy a heli.
Harold
quickfighter is offline        Reply With Quote
Old 03-14-2010, 06:59 PM   #16
Pinecone
Registered Users
 
Posts: 18,335
 

Join Date: Sep 2006
Location: Maryland
Default

A faster servo for the tail will also help.

That servo is 0.16 at 4.8 volts. I run an S9254, which is 0.06 second.
__________________
Terry
AMA#47402, IRCHA # 3395
Blade CP "Pro", Trex 450SE, PiccoZ, Quick of Japan EP8v2 EX, Hurricane 550, Hurricane 200, JR Vibe 50, Blade mCX, Bergen Intrepid Gasser, Pantera 50, Blade mSR, Novus CP
Pinecone is offline        Reply With Quote
Old 03-15-2010, 09:34 AM   #17
quickfighter
Registered Users
 

Join Date: Jan 2010
Location: Marshville N.C.
Default

Hey Terry,

That is a good servo. I am glad to see you helping us out, I think you have a good flying EX. Is that the servo that comes with a 401 ?

Harold
quickfighter is offline        Reply With Quote
Old 03-15-2010, 01:26 PM   #18
Pinecone
Registered Users
 
Posts: 18,335
 

Join Date: Sep 2006
Location: Maryland
Default

Yeah, that is the standard size tail servo that comes with some 401 kits. You can also get the 401 with a min servo (S9650).

I run the 401 with S9254 on my EP8, Hurricane 550 and Pantera Nitro. I run the JR 770 3D with 8900G on my Vibe and Bergen Intrepid Gasser.
__________________
Terry
AMA#47402, IRCHA # 3395
Blade CP "Pro", Trex 450SE, PiccoZ, Quick of Japan EP8v2 EX, Hurricane 550, Hurricane 200, JR Vibe 50, Blade mCX, Bergen Intrepid Gasser, Pantera 50, Blade mSR, Novus CP
Pinecone is offline        Reply With Quote
Old 03-15-2010, 05:09 PM   #19
quickfighter
Registered Users
 

Join Date: Jan 2010
Location: Marshville N.C.
Default

I knew you had all the good stuff! I did get the latest JR 500 size Gyro from Charles last month. It has been great in this wind lately.

Charles has a new battery tray coming for the EX.

Harold
quickfighter is offline        Reply With Quote
Old 03-27-2010, 02:43 AM   #20
PAS
Registered Users
 
Posts: 153
Thread Starter Thread Starter
 
My HF Map location
Join Date: Jun 2007
Location: Roseville, California
Default

I just swapped the Hyperion servo in the tail for a Hitec HSG-5084 (over 2X faster) and the tail seems very locked in with no wag.
__________________
Compass Atom 500 to replace Quick of Japan EP8
Dragonus II N-Plus
Gaui 330x-S
PAS is offline        Reply With Quote
Reply




Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Other Makes and Models Helicopters > Quick of Japan


Quick of Japan QJ Helicopters

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Copyright © 2004-2015 by RCGroups.com, LLC except where otherwise indicated. The HeliFreak.com logo is a trademark of RCGroups.com, LLC.