Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Electronics Support > JR and Spektrum Radios and Electronics > 2.4G JR Radios


2.4G JR Radios JR 2.4 Gigahertz Radios and Technology


Reply
 
Thread Tools Display Modes
Old 03-29-2010, 01:17 AM   #1
Sveberg
Registered Users
 

Join Date: Nov 2007
Location: Norway
Default X9503 - End Points at Gear Channel for Gyro gain

Hi,

I am trying to understand the math on how to find the proper end points for the Gear channel, when using the Gear channel for gyro gain. I have not been able to find any detailed discussions on this, so hopefully this post is of interest for others also....

In the Gyro sense meny, gain from 50-100 is Heading Hold and gain from 0-50 is Rate mode. When using end points in the gear channel, you will have Heading hold with Gear switch ON and Rate mode with Gear switch off. This means I will have values from 0-100% for Heading Hold when Gear switch is on.

I am flying with 70% gyro gain in Gyro sense menu on my AR7100 receiver (TRex 500). Now I have an AR6100 in a TRex 450 pro, meaning I have to use the Gear channel and end points for gyro gain. I want to start with about the same gain as on my 500...

In the Gyro sense menu, a gyro gain of 50% = 0% true gain. So, compared to end points, 0% true gain = 0% end point. When setting 70% gain in the Gyro sense menu, I am 20%-points above 0% true gain => 2/5 between 0% gain and 100% gain. Transferred to gear channel end points, 2/5 of 100% available end point adjustment = 40%.

So, In my mind, a 40% setting in gear channel Travel Adjust menu should equal a 70% gain in the Gyro sense menu - am I right...??
__________________
T-Rex 450 PRO, HK 2221-6, GP720, Jazz 40, 3s 2200, HS5065MG, JR DG3500
T-Rex 500 CF, Kontronic MiniPyro, ds760, Jive 80+HV, HS-5245MG, S9257, 6s 3000
T-Rex 600 ESP, HK 4025-740, ds760, Jazz 55-10-32, Outrage 3700 10s, DS8717, DS8900G
Sveberg is offline        Reply With Quote
Old 03-29-2010, 08:16 AM   #2
Bob O
HF Support
 
Posts: 27,440
 
My HF Map location
Join Date: Dec 2008
Location: Negaunee, Michigan
Default

There are two camps on this, one that thinks the equation is 2 to 1, and the other says 1.44 to 1. I'm in the first camp as 2 to 1 makes the most sense, ie: your example of 40% in endpoints equals 70% gain. I've never been able to understand the 1.44 idea.

With that said, I've set up two helis for friends using endpoints for gain. One was a B400 with HG-5000 gyro, the other a T-Rex 450 with the same gyro. I used the 2 to 1 conversion to set gains as high as 90% (80 in endpoints). With the HG-5000, there are lights that correspond to gain ranges (not extremely accurate but gives a visual idea) and the 2 to 1 conversion corresponded to the position of the lights.

But the bottom line should be how the tail performs, not exactly the number you end up at. Regardless of the number, increase the endpoints until you get wag then back it off until it's gone. Whatever number you end up with is where you end up.

I guess a good way to compare would be if you could use both Gyro Sense AND endpoints on the same heli. Like make adjustments in Gyro sense until you get to a certain performance level. The change to endpoints and set it for the same performance level and see what number you end up with.

Good luck!!!
__________________
):> Team HeliFreak
SPARTANRC - R&D Team
GAUI X4II - VX1e -
OmG servos
Futaba 14SG
Bob O is online now        Reply With Quote
Old 03-29-2010, 08:38 AM   #3
Pinecone
Registered Users
 
Posts: 18,335
 

Join Date: Sep 2006
Location: Maryland
Default

Quote:
Originally Posted by Bob O View Post
But the bottom line should be how the tail performs, not exactly the number you end up at. Regardless of the number, increase the endpoints until you get wag then back it off until it's gone. Whatever number you end up with is where you end up.
+1
__________________
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 03-29-2010, 08:41 AM   #4
Rototerrier
Registered Users
 
Posts: 2,340
 

Join Date: Dec 2007
Location: Fayetteville, GA - USA
Default

Quote:
Originally Posted by Pinecone View Post
+1
+2

Crank it till it wags or hunts and then back it down a bit. Done deal.
__________________
700 Helibug GAS 16t Helical | VBar Silverline | 290 FrankenEngine
HeliXHeli 700 | VBar Silverline | TRM275TT
TREX 550 V2 DFC | µBeast | CC Ice 100 | CC BEC Pro
Rototerrier is offline        Reply With Quote
Old 03-29-2010, 08:51 AM   #5
mediclavina
Registered Users
 
Posts: 1,064
 

Join Date: Jul 2006
Location: Louisiana, USA
Default

The formula I follow for a JR radio is:
End_point_value / 1.27 = True_Gain_value

So an end-point value of 32 gives 25% true gain.
__________________
GAUI EP-200 V2 FBL, Blade Nano CPX, Blade mCP-X, Hirobo SRB Quark, Blade mSR, Blade mCX
mediclavina is offline        Reply With Quote
Old 03-29-2010, 11:14 AM   #6
Sveberg
Registered Users
Thread Starter Thread Starter
 

Join Date: Nov 2007
Location: Norway
Default

Thank's for your comments.

I know that two different heli's will not perform the same with the same setting, meaning that I have to identify the proper setting for my heli. But, I am looking for an understanding of the relationship between using gyro sense settings and end point settings. That way, I can at least make a reasonable starting point for the end point settings.

According to Bob O I have got it about right...
__________________
T-Rex 450 PRO, HK 2221-6, GP720, Jazz 40, 3s 2200, HS5065MG, JR DG3500
T-Rex 500 CF, Kontronic MiniPyro, ds760, Jive 80+HV, HS-5245MG, S9257, 6s 3000
T-Rex 600 ESP, HK 4025-740, ds760, Jazz 55-10-32, Outrage 3700 10s, DS8717, DS8900G
Sveberg is offline        Reply With Quote
Old 03-31-2010, 09:00 AM   #7
Pinecone
Registered Users
 
Posts: 18,335
 

Join Date: Sep 2006
Location: Maryland
Default

Quote:
Originally Posted by Rototerrier View Post
+2

Crank it till it wags or hunts and then back it down a bit. Done deal.

Better is to crank it up if the tail doesn't hold. IOW, run the lowest gain that will hold the tail for YOUR flying.
__________________
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
Reply




Unregistered
Go Back   HeliFreak > R/C Electronics Support > JR and Spektrum Radios and Electronics > 2.4G JR Radios


2.4G JR Radios JR 2.4 Gigahertz Radios and Technology

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 © 2004-2011 - William James - Helifreak.com