Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Radio Equipment => Topic started by: Tug-Kenny RIP on December 28, 2012, 03:10:32 pm

Title: Servo Direction
Post by: Tug-Kenny RIP on December 28, 2012, 03:10:32 pm


        NEW YEAR CRACKER PUZZLE


Is it true to say that a servo will rotate the arm Right when the Transmitter lever is pushed to the right.  ?????

What way will it turn if the the T/X lever is pushed upwards,  (when connected to another channel of course).

Is it possible to reverse this action by altering the servo in some way. ??


Cheers

Ken



Title: Re: Servo Direction
Post by: Big Ada on December 28, 2012, 03:52:06 pm
Er, Why?. {:-{
Title: Re: Servo Direction
Post by: Bob K on December 28, 2012, 04:34:53 pm
Er, Why?. {:-{

Sometimes it is necessary to have two servos on a single channel, one turning in the opposite direction. eg: aircraft ailerons or bow & stern rudders.  Some analogue servos can be modified internally, or simply buy a JP Y lead with servo reverser.
Title: Re: Servo Direction
Post by: Tug-Kenny RIP on December 28, 2012, 04:45:09 pm

My point was to see which way they ALL turn when new, or does it depend on pot luck ?

The question arises when fitting rudder control, as Bob says.  Until you connect it up and find it goes the wrong way around.  At the moment I'm working on the theory that last boat turned clockwise on rudder right, but will it do it with the next one ?     :}


Ken

Title: Re: Servo Direction
Post by: Timo2 on December 28, 2012, 05:15:17 pm
Hi


   1 = Buy a Servo Swinger .


   2 = Turn Servo 180 '


   3 = Buy a servo reverser eg. =       
                     http://www.hobbyking.com/hobbyking/store/__17033__Turnigy_Servo_Signal_Reverser.html

   Hope this helps

  Timo2
Title: Re: Servo Direction
Post by: barriew on December 28, 2012, 05:21:52 pm
Surely it depends on how you install (align) the servo in the boat  %) :}  If you always install (align) them the same way, then yes they will always turn the same way, assuming no reverser is enabled.


Barrie
Title: Re: Servo Direction
Post by: Bob K on December 28, 2012, 06:39:21 pm
   2 = Turn Servo 180 '
 Timo2

   2  = If it turns clockwise on right/up it will still turn CW if turned 180' (with the spindle still at the top).
         Another option is to cross the linkage across the centre line.,  ie Servo port side to Rudder s/bd side
 
At this point we should own up to turning on each of our boats to see what happened  O0
Mine all go CW
Title: Re: Servo Direction
Post by: Circlip on December 28, 2012, 06:48:09 pm
From memory, Sanwa mini-servos were orientation noted by the fact that one digit in the type number denoted whether clock or anti clock rotation was the norm. eg. 350 was clock and 351 was anti. or vicky verky, so that in the mini-two set, you got one of each.
 
  "Servo Shop's" Hitec HSC-5996 TG and 5997  may be opposite rotation.
 
  Regards  Ian.
Title: Re: Servo Direction
Post by: Umi_Ryuzuki on December 28, 2012, 06:50:26 pm
If the servo turns clockwise when the joystick is moved to the right, then if you
want the control rod to PUSH, then mount the control rod on the three o'clock side.
If you want the control rod to PULL when the joystick is moved to the right, then
mount the control rod on the nine o'clock side.
(assuming your rudder is at the six o'clock position...)
 ok2
Title: Re: Servo Direction
Post by: Tug-Kenny RIP on December 28, 2012, 07:52:29 pm
From memory, Sanwa mini-servos were orientation noted by the fact that one digit in the type number denoted whether clock or anti clock rotation was the norm. eg. 350 was clock and 351 was anti. or vicky verky, so that in the mini-two set, you got one of each.
 
  "Servo Shop's" Hitec HSC-5996 TG and 5997  may be opposite rotation.
 
  Regards  Ian.


Thanks for the details Ian.   I've had a look at the comprehensive range which was very impressive.

But ....  no mention of which way they Turn.     %)

Regards

Ken
Title: Re: Servo Direction
Post by: tony23 on December 28, 2012, 10:56:17 pm
am I reading this right that all you guys don't know how to make your servo move the other direction if it need too
Title: Re: Servo Direction
Post by: derekwarner on December 28, 2012, 11:04:14 pm
Just send them down to OZ tony23.. we guarantee to make anything go backwards/upside down........ {-)  ...mind you by the time we send the back....their polartiy will have probably reversed itself again..... %% .......Derek
Title: Re: Servo Direction
Post by: tony23 on December 28, 2012, 11:06:37 pm
Hi Dereck,
         Even water down the plug hole  {-) {-) {-)
Title: Re: Servo Direction
Post by: RAAArtyGunner on December 28, 2012, 11:14:38 pm
am I reading this right that all you guys don't know how to make your servo move the other direction if it need too

 O0 O0 O0
 
C'mon Derek and Tony, and the answer is.........................
the suspense is killing me O0 O0 O0
Title: Re: Servo Direction
Post by: Tug-Kenny RIP on December 29, 2012, 10:13:02 am

The original question is still not answered.

The only point to this thread was to determine if all servos are supposed to turn to the right on right stick movement, or is it pot luck when you select one.  :}


Ken

Title: Re: Servo Direction
Post by: tony23 on December 29, 2012, 10:29:02 am
The servos turn in the direction that the transmitter is programmed to so if the servo when fitted is turning the wrong direction you want you simply go into the programming mode in the transmitter and reverse the direction!
this is from my futaba manuel
To reverse a servo:
1) Turn the transmitter on.
2) Press and hold the MODE button to access the programming mode.
3) Press either the MODE key OR the END key to scroll through the function menus.
Continue pressing the MODE or END key until the reverse (REVR) menu appears
on screen.
4) Press the SELECT key to select the channel you wish to reverse.
5) Push the DATA INPUT lever downward for 0.5 seconds to reverse (REV) the servo. Press the DATA
INPUT lever upward for 0.5 seconds to make the servo operate in a normal (NOR) direction.
6) Repeat the steps above to bring forth and modify any other channels for which the travel direction is to be
altered.
7) Press and hold the END button to exit the servo reverse menu.
 
Title: Re: Servo Direction
Post by: Netleyned on December 29, 2012, 11:10:57 am
If your tx is not computerised you have a servo reverse switch for each channel normally.

Ned
Title: Re: Servo Direction
Post by: Timo2 on December 29, 2012, 11:21:45 am
If your tx is not computerised you have a servo reverse switch for each channel normally.

Ned


OR    Turn it  a 180' to reverse it  O0


 Timo2
Title: Re: Servo Direction
Post by: knoby on December 29, 2012, 11:46:18 am

Ken, just out of curiosity I tried a few servos last night to see.
2 Futaba S148 both turned clockwise when stick pushed to right.
Hi Tec  808mg turned anti clockwise when stick pushed to right.
Power HD 9001 mg turned clockwise when stick pushed to right.
So there doesn't seem to be a standard set for servo direction, although same types do seem to turn the same way. Given that most modern servo feedback pots are soldered directly on to the pcb, I think its fair to assume that all similar servos models would turn the same way, although different models from the same manufacturer may not.
Of course, you have to take into account, most are made in China, & given their reputation for quality control, I wouldn't bet my house on any of the facts above.

Cheers Glenn
Title: Re: Servo Direction
Post by: Bob K on December 29, 2012, 11:50:45 am
OR    Turn it  a 180' to reverse it  O0 
 Timo2

As I replied before, with the actuating spindle at the top turning the servo 180' it will still turn the in the same direction.  ie:  Clockwise.  Try it
Title: Re: Servo Direction
Post by: Martin (Admin) on December 29, 2012, 12:20:10 pm
 
It seems to depend on your particular TX and it's setup Ken, but the "default"  seems to be that
pushing the 'stick' up or to the right should increase in the output signal's 'pulse width'  which
should turn the servo clockwise.

http://www.pololu.com/blog/17/servo-control-interface-in-detail
http://www.scriptasylum.com/rc_speed/radio.html

Title: Re: Servo Direction
Post by: Norseman on December 29, 2012, 12:59:18 pm
Never ceases to amaze me that simple questions never have simple answers. More food for thought and I'll continue to follow.
Dave
Title: Re: Servo Direction
Post by: Circlip on December 29, 2012, 02:12:50 pm
Still needs the manufacturers individual spec sheets. It used to be important before servo reversing switches and computerised TX's. where you had to plan the layout.
 
  Another one to ponder, how many rely on just pushing the "Trim" lever instead of determining trim when operating, coming back to Firma Terrer disconnecting the linkage, screwing the adjuster and re-setting the trim lever to central?
 
  Regards   Ian.
Title: Re: Servo Direction
Post by: tony23 on December 29, 2012, 06:26:24 pm
I have been modelling for years and a first should be to get your push rod at  90degrees to the servo horn and control linkage through manual adjustment if need be that way the travel will be the same in each direction.
Title: Re: Servo Direction
Post by: Martin (Admin) on December 29, 2012, 08:45:23 pm
(http://www.seattlerobotics.org/guide/images/pulse_code.jpg)

http://www.seattlerobotics.org/guide/servos.html
Title: Re: Servo Direction
Post by: Tug-Kenny RIP on December 30, 2012, 11:35:30 am

Thanks for the info Martin.  That explains it beautifully.

I knew there was more to this than meets the eye.  I have been through all my stock of fitted and unfitted servos and they all turn right, on pushing the stick right.  I am now convinced it's the T/X controls that govern the situation. My T/X does have a reversing switch which works but I do not use it as it's best to keep all models set to standard.  I must admit that I didn't know it was down to the T/X, which is why I wrote in the first place.

I also have a few servos with the 'mechanical stop button' removed and a balance set of resistors fitted, so that they can be used for continuous rotation in my crane.  These also rotate the correct way around, so all is well.

Thank you all for your input.   :-))


ken
 
Title: Re: Servo Direction
Post by: Circlip on December 30, 2012, 12:16:42 pm
Quote
I am now convinced it's the T/X controls that govern the situation.

   No Kenny, it's down to the servo manufacturer as to which way the feedback  pot and the motor are wired. I mentioned the Sanwa mini two and a servo of each rotation was supplied.
 
  The TX pot may be wired so that RH movement of the stick increases the signal length but the reversing switch "Reverses" that.
 
  It should also be noted that although the "convention" for M/S is 1.25 / 1.5 / 1.75 early Futaba was 1.3 / 1.5 / 1.7 so they would only work properly with Futaba gear.
 
  Regards  Ian.
Title: Re: Servo Direction
Post by: Tug-Kenny RIP on December 30, 2012, 12:45:09 pm

Thank you for that Ian.

If I wanted to reverse the action of an individual servo then would I just reverse these two sets of wires ?   ( motor and supply to the twin resistors?)

Cheers

Ken



Title: Re: Servo Direction
Post by: Circlip on December 30, 2012, 01:08:48 pm
The connections I'm referring to are inside the servo casing.
 
  Regards   Ian.
 
 
     http://www.youtube.com/watch?v=EK_FdRTenl0 (http://www.youtube.com/watch?v=EK_FdRTenl0)
Title: Re: Servo Direction
Post by: Martin (Admin) on December 30, 2012, 02:43:44 pm
 
Some servos are almost impossible to get at the wires without destroying it but you may be able to fit a switch to the transmitter.

http://www.rcgroups.com/forums/showthread.php?t=387127
http://www.rcgroups.com/forums/showthread.php?t=1505333


http://www.ebay.co.uk/itm/Turnigy-RC-Servo-Signal-Reverser-Rotation-for-JR-Futaba-Aeroplane-V-Tail-Reverse-/160862474288?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item2574269030


Title: Re: Servo Direction
Post by: Circlip on December 30, 2012, 03:57:46 pm
Quote
Some servos are almost impossible to get at the wires without destroying it

 
 
If an Oriental can make it, a Brit can mod it   :-))    {-)
 
  But as Kenny stated, although he has reversing switches on the TX, he wants to keep the controls "Standard".
 
  Regards  Ian
Title: Re: Servo Direction
Post by: malcolmfrary on December 30, 2012, 04:30:59 pm
Thank you for that Ian.

If I wanted to reverse the action of an individual servo then would I just reverse these two sets of wires ?   ( motor and supply to the twin resistors?)

Cheers

Ken
Basically, yes.  They tend to be fiddly to get at, but it can be done.  If the pot and the motor are wired to the board, life is fairly simple, but some have one or both soldered direct to the board.  In the case of the pot, modding would involve cutting the end legs and cross-wiring.  Direct soldered motors typically have three legs - two for power, one each side, and one halfway between for the can.  Reversing involves unhitching all three, flattening the can one out of the way and wiring it to its original hole, refixing the motor 180˚ from its original position.  The can connection hooks to the onboard suppression capacitors.
Title: Re: Servo Direction
Post by: JayDee on December 30, 2012, 05:26:48 pm
Hello,
Servo reversing can be done with the linkages.
Back in the "Good old Days" we had no reversing, it was all done with the linkages.
Come On Chaps, get your thinking heads on.
Post some details of a setup that needs "reversing" and lets see the problem.
 
John.  :-))
Title: Re: Servo Direction
Post by: Umi_Ryuzuki on December 30, 2012, 06:32:27 pm
Basically, yes.  They tend to be fiddly to get at, but it can be done.  If the pot and the motor are wired to the board, life is fairly simple, but some have one or both soldered direct to the board.  In the case of the pot, modding would involve cutting the end legs and cross-wiring.  Direct soldered motors typically have three legs - two for power, one each side, and one halfway between for the can.  Reversing involves unhitching all three, flattening the can one out of the way and wiring it to its original hole, refixing the motor 180˚ from its original position.  The can connection hooks to the onboard suppression capacitors.

I think what he really means,... Is No you can not simply reverse the red and black wires.
You have to leave those wires alone. But yes, reverse the polarity at the motor, and the reverse
the two outside wires on the potentiometer.  O0
Title: Re: Servo Direction
Post by: Martin (Admin) on December 30, 2012, 07:10:47 pm

Back in the "Good old Days" we had no reversing, it was all done with the linkages.


"That's crazy talk man!!!!" There was never a time with electronics and the internet.... ask my kids!"     {-)
Title: Re: Servo Direction
Post by: JayDee on December 30, 2012, 07:40:27 pm
Title: Re: Servo Direction
Post by: JayDee on December 31, 2012, 01:17:32 am
Hello,
Well, what has happened to all the rewiring, servo chopping and altering ect,ect ???.
John.  ok2