RC India
Welcome Guest, please login or register.
 
Pages: [1]   Go Down
0 Members and 1 Guest are viewing this topic. Topic Tools Topic Tools 
Read
« on: October 05, 2014, 09:58:40 AM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012




I have a RCB7x radio , all of a sudden the throttle potentiometer broke off. Now i have replaced the throttle and it works.
But the problem is that , when verified in the stick movement display - the movement is not as much as in real world.
I have also tried adjusting the EPA to +-150% still the movement is very little.Is there any way to calibrate the stick movement in the software?

tx_error_1.jpg
RCB7x Stick calibration
* tx_error_1.jpg (71.71 KB, 800x450 - viewed 836 times.)
This post has 1 more images(s)/attachment(s). Please login or register to view them.
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #1 on: October 07, 2014, 02:26:50 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012


Re:

Could anyone specify the manufacturer or the original model of this OEM  branded radio ?
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #2 on: October 08, 2014, 02:19:20 AM »
akhilzid
Heli Lover
Forum Hero

*****

Reputation Power: 5 
akhilzid has no influence.
Offline Offline

City: Ernakulam
State: Kerala
RC Skills: Advanced
Posts: 541
Join Date: Sep, 2014



may the potentiometer that you replaced was different in Ohms from original, try to replace with new potentiometer having the same Ohms value as original,
To get the value you can measure Ohms from broken or other working potentiometer in that tx.
Logged
 

Read
« Reply #3 on: October 11, 2014, 06:46:07 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012



You're right , the original POT was 5K but this new replacement is 5.2K , still the output will be the same voltage at the same wiper position ?
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #4 on: October 11, 2014, 07:09:56 PM »
akhilzid
Heli Lover
Forum Hero

*****

Reputation Power: 5 
akhilzid has no influence.
Offline Offline

City: Ernakulam
State: Kerala
RC Skills: Advanced
Posts: 541
Join Date: Sep, 2014



0.2 ohms will be a major diffrence in this case.but u can use less than 5k ohms potentiometer with trim enabled.
Logged
 

Read
« Reply #5 on: October 11, 2014, 11:27:34 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012


Re:

But these replacement pot are not easily available - the shape is very specific
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #6 on: October 11, 2014, 11:51:56 PM »
akhilzid
Heli Lover
Forum Hero

*****

Reputation Power: 5 
akhilzid has no influence.
Offline Offline

City: Ernakulam
State: Kerala
RC Skills: Advanced
Posts: 541
Join Date: Sep, 2014



Dont try if U hav enough experiance and dont blame me if it goes wrong,

if u hav any doubt just ask me before doing this.


i done this many times and the result is success
Try dismantling POT and solder some led in the joints between resistive meterial and the connector as shown in the picture will reduce resistance,

images.jpg
Re: RCB7x Stick calibration
* images.jpg (11.36 KB, 271x186 - viewed 729 times.)
Logged
 

Read
« Reply #7 on: October 12, 2014, 09:01:01 AM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012


Re:

That's an excellent idea , but this is a sealed plastic case pot -so it's difficult to make this mod
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #8 on: October 12, 2014, 12:58:06 PM »
akhilzid
Heli Lover
Forum Hero

*****

Reputation Power: 5 
akhilzid has no influence.
Offline Offline

City: Ernakulam
State: Kerala
RC Skills: Advanced
Posts: 541
Join Date: Sep, 2014



can u post images of the pot?
Logged
 

Read
« Reply #9 on: October 13, 2014, 04:38:13 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012



Image of the shaft/wiper of the POT and the original broken pot from RCB7x

IMG_20141013_075243.jpg
Re: RCB7x Stick calibration
* IMG_20141013_075243.jpg (48.3 KB, 800x450 - viewed 690 times.)
This post has 1 more images(s)/attachment(s). Please login or register to view them.
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #10 on: October 13, 2014, 05:12:03 PM »
sooraj.palakkad
with eyes in sky
Heli Lover
Forum Hero

*****

Reputation Power: 21 
sooraj.palakkad barely matters.sooraj.palakkad barely matters.
Offline Offline

City: Palakkad
State: Kerala
RC Skills: Expert
Posts: 2058
Join Date: Aug, 2014

SPN



For Decreasing resistance of a pot there is no need to open and add lead to the resistance track, just add an appropriate value of resistance in parallel to POT !!!

You have 5.2K POT and need to decrease it to 5K,  Just add a 130K Resistor in parallel to POT.

In parallel combination, Total resistance R=(R1R2)/(R1+R2)
Assume your POT is R1 = 5200ohm,
and total resistance needed is 5000ohm,
So, 5000=(5200*R2)/(5200+R20,
By deducing R2=130000ohm = 130K.

 Thumbs Up Thumbs Up
Logged

RC Hobbyist and an Aerial Cinematographer..
 

Read
« Reply #11 on: October 13, 2014, 05:57:29 PM »
K K Iyer
Global Moderator
Forum Hero
*****

Reputation Power: 61 
K K Iyer is a rising star!K K Iyer is a rising star!K K Iyer is a rising star!K K Iyer is a rising star!K K Iyer is a rising star!K K Iyer is a rising star!
Offline Offline

City: Indore
State: Madhya Pradesh
RC Skills: Intermediate
Posts: 5180
Join Date: Jan, 2012



+1 to sooraj.
Logged
 

Read
« Reply #12 on: October 13, 2014, 06:18:34 PM »
sooraj.palakkad
with eyes in sky
Heli Lover
Forum Hero

*****

Reputation Power: 21 
sooraj.palakkad barely matters.sooraj.palakkad barely matters.
Offline Offline

City: Palakkad
State: Kerala
RC Skills: Expert
Posts: 2058
Join Date: Aug, 2014

SPN



Thanks, Sir.
I am new to rc, however know some thing in electronics and embedded systems. Hats Off
Logged

RC Hobbyist and an Aerial Cinematographer..
 

Read
« Reply #13 on: October 15, 2014, 09:43:36 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012



Found the problem  when I opened up the POT. In normal POT the resistive trace is available for 210 deg or so ,then the whole range of voltage variation is available only in 210 deg. But in this case of gimbal POT the total variation of the voltage must be constrained within the movement of the gimbal so the trace is available only for 80 deg which makes it difficult to replace it with a normal POT.

Removed the case of the POT.

Transplant the good wiper knob to the damaged POT

Fix the wiper contact onto the new knob

The resistance track constrained within 80 deg.

IMG_20141015_190128.jpg
Re: RCB7x Stick calibration
* IMG_20141015_190128.jpg (39.72 KB, 800x450 - viewed 686 times.)
This post has 3 more images(s)/attachment(s). Please login or register to view them.
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #14 on: October 15, 2014, 09:49:01 PM »
akhilzid
Heli Lover
Forum Hero

*****

Reputation Power: 5 
akhilzid has no influence.
Offline Offline

City: Ernakulam
State: Kerala
RC Skills: Advanced
Posts: 541
Join Date: Sep, 2014



Good  Clap Clap Clap

Check and post the results.
Logged
 

Read
« Reply #15 on: October 15, 2014, 09:51:50 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012



Normal POT trace nearly 300 deg

http://www.geofex.com/article_folders/potsecrets/pot5.JPG
RCB7x Stick calibration


There was misalignment in fixing the case

The range works as expected

IMG_20141015_195804.jpg
Re: RCB7x Stick calibration
* IMG_20141015_195804.jpg (61.91 KB, 800x450 - viewed 662 times.)
This post has 2 more images(s)/attachment(s). Please login or register to view them.
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Read
« Reply #16 on: October 15, 2014, 09:53:24 PM »
santhosh-r
Plane Lover
Forum Hero

*****

Reputation Power: 7 
santhosh-r has no influence.
Offline Offline

City: coimbatore
State: Tamil Nadu
RC Skills: Intermediate
Posts: 596
Join Date: Dec, 2012



In general , its very rare to find a replacement POT for the gimbals in our Radio systems. You have to buy a new gimbal replacement unit instead of a single POT costing around Rs.10 .
Logged

Spektrum DX6i | Phoenix V4 | CoroTrainer | Tamiya Baja king 2WD | RCTimer F450 Quadcopter
 

Pages: [1]   Go Up
Jump to:  

Related Topics
Subject Started by Replies Views Last post
Why can’t HK FC board remember calibration
Multirotors
atulrajguru9 10 5199 Last post January 10, 2013, 07:22:50 PM
by atulrajguru9
Esc calibration help! Urgent
Multirotors
Aeroempire 7 3659 Last post December 18, 2014, 09:08:22 PM
by akhilzid
Multirotor calibration
Electric Power
vihang.vaidya 3 2789 Last post December 24, 2015, 11:38:29 AM
by Darshan for multirotors
ESC calibration
Servos, Gyros and All Electronics
Vysh975 0 1878 Last post July 15, 2016, 11:54:39 PM
by Vysh975
Kk 2.1.5 yaw esc calibration problem
Multirotors
Rcjabalpur 1 3176 Last post December 06, 2019, 08:23:54 PM
by Yedhu