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[GARY C]

Hi,
Help,  I have a supertec s06/2bb servo as new condition. When it is connected into the receiver and radio swiched on, the
servo self sweeps on its own. Like the wipers on a car.
Is there a majic spray to apply ?
Is it repairable ?
Or does it go into the skip ?  :'(

Any ideas ?    cheers, Gary.

[catengineman]

daft question time but have you got the plug in the reciever the right way round ?

IE: ground to the ground in the rec, signal to the signal in the rec, and the power to the power in the rec.
from past I have found that not every servo etc are wired the same way though I cant remember the make of the ones that differ.  just a thought

[GARY C]

Hi,
Good thought,
the plug has 3 wires, red-black-white. I had to trim the lug off to make it fit into the receiver (hitec 2 ch 40mz am) which was allready installed in my Victora yacht, unpluged one servo and swapped  it for this one.
If I swap the plug around can I do any damage to the rec, eg spike it?.

Are the colours of the wires supposed to follow inline, e.g. if the battery red wire is in pin 1 of the rec, do the servo red wires follow suit e.g. pin 1 again?.

Gary.

[catengineman]

All the wires need to fit to the corresponding part in the rec but here is where I fall short on the info if I can remember MY rec terminals the white (signal wire) is inward to the rec box and the Black (ground wire) is to the outer side but different rec's and different servo makes could throw a spanner in my posting.

I think that if it is white then follow the working white wires but if the colours are say "brown - orange" etc I think there is requirement of a greater mind than mine

sorry I cant help that much my models are at home and Im on a rock dodger

R,

[Peterm]

Generally speaking, ithe black (or sometimes brown) wire goes to the outside edge of the rx socket.   I have on the odd occasion got it the wrong way round with no damage done.   Pete M

[GARY C]

Thanks for the help  
Off to work soon, so will check and investigate tomorrow.

cheers

[John W E]

Hi all

I have just made a quick scribble of the various wire configurations for different servo plugs.

Hope this may be of some help.

Some plugs have chamfers on them and when I view these, I view the chamfers on the bottom and the wire is facing away from me.

aye
john e
bluebird

[malcolmfrary]

The normal configuration these days is Black (or Brown) is neg, and the pin nearest the outside of the RX, Red is pos, and the centre pin, white (or orange, or yellow) is the signal, and most inboard.
This arrangement has the advantage that if plugged in in reverse, nothing at all should happen, as the red pos is in the right place, the neg is connected to an RX output that is probably incapable of providing any power, and the signal wire is grounded, but cant do anything because it needs a pulsing signal, and isnt getting one.
Is it just giving one sweep, or is it cycling backwards and forwards?  A single sweep is a sign that the position sensing pot or its associated circuit is broken and the servo is trying to drive to a position that it cant get to to agree with the position of the stick on the TX - cycling would be a new one for me.

[Jonty]

  I've just bought a new Zebra 4 channel set and have a similar problem. If the power to the Rx is switched on before the Tx is, the steering servo oscillates rapidly. Once the Tx is switched on it behaves OK.

[John W E]

Jonty, hi there

In your instructions for the radio gear, it should state - ALWAYS SWITCH TRANSMITTER ON FIRST FOLLOWED BY YOUR RECEIVER  :)  Its a fact of today's life that all electronics are starting to use what is called PIC chip

There will be several of these chips in your receiver as well as in your speed controller, switchers and soforth.  One of the first things the PIC chips do is once you apply the power to them, is to start looking for a central signal.  That is why you are getting eratic jitters/movement from your servos as though they are going mad.  This is because they have not got a centralising set up signal from your transmitter.   

This is where on some speed controllers, people think there is something wrong with them.  What they may have done is switch their receiver on first or when they have switched the transmitter on, the throttle stick may have been on the wrong position.

Hope this is of some help.

aye
john e
bluebird

[DickyD]

I had this problem when I tested one of my boat electrics in my shed. With Tx and Rx both switched on the rudders oscillated and the motor started and stopped on its own.
Took a long time and lots of checking before I realized that the Tx antenna was near the flourescent light fitting.
Turned of the light, problem solved. 

[Circlip]

    Sorry Bluebird , I would beg to differ re turning on TX first.  At  home OK in the confines for setting up, but out
     in the field always RX first and wait at least half a minute.to check wether ANY interaction Both you and I know what colours and channel numbers
     are and would go to great lengths to ensure everything matches, BUT as I mentioned in another thread, I was ONCE
     caught out by a newbie flying a flag of CONVENIANCE. I was on BLUE, he was on BROWN (well his FLAG was) managed
     to LAND without damage to either model. He LIKED the goldy/brown colour out of the ones supplied with his gear.
     I know it's less likely with a boat but in the event of a 'speed' model going out of control I would always err on the
     side of prevention being better than cure. One question that you may be able to answer in this same thread. What
     is the difference between the new DIGITAL servos we see advertised at ridiculously low prices on fleebay and the
     three/four wire servos I'm used to? OK I know about C/T's and frame rates of older types, but could I plug one of
     these into a SANWA MINI TWO ? Asking this because I would suspect HITEC 40meg AM doesn't have PIC's etc.
     and if it does matter is the servo mentioned compatible with the RX?

        Ian

[Martin (Admin)]

Futaba, JR, etc say to switch on transmitter first to prevent the receiver and servos "freewheeling" ie. servos picking up near frequencies and trying to drive past their end stops. But good point to check if your radio homes in on someone else on the same frequency.

[John W E]

Hi thereCirclip, well I am afraid that if you apply your method of switching the Rx on first you will find some of your speed controllers and switchers on the market today will not function properly.

It is always, always best to check the frequency board first whether in a model boat, car, plane or whatever, it is your responsibility.   Ones ignorance if one prefers to ignore this.

aye
john e
bluebird

[Peterm]

As already said, Tx first, then Rx.   However, I use a frequency monitor before I switch Tx on.   These are available for all RC bands.
Pete M

[Circlip]

    John,Peter totally agree with principle you state, but there have been too many people killed due to 3rd axis accidents
     so I prefer to accept a 'missfire' on the pondside. You CAN control a group of like minded club members, but, little
     Freddie whose just bought a MAPLIN or FLEEBAY cut price, and is sailing or driving just round the corner hasn't been
     informed about interaction or signal monitors. Have ALWAYS worked on the principle that I make shure that my
     enjoyment don't inconvenience anyone else, oh that they should grant MY enjoyment the same.

         Ian

[malcolmfrary]

The RX or TX switched on first question comes down to knowing your gear.  Having an RX and associated gear that is happy with no signal, switch the RX on first and see if anybody else is using "your" channel.  This is the easiest way of checking that no-body else is using your frequency.  However, if you have anything with a PIC inside it, it will mis-behave in some way without a signal to lock onto at switch-n, so your TX has to be switched on first in that case.
I/C boaters  usuallygo TX first to prevent the motor over-reving when switching the radio on.
If you do have to switch the TX on first, it is good manners to look and ask if anybody else is on "your" channel, and if a pegboard is in use, to use it.  Even then I have seen a set with crystals with red paint, and the right numbers for red, actually turn out to be brown.  There are some things that you just can't legislate for.

[wingertaz]

I Haven't come across any manufacturer of radio gear who condone switching the RX on before the TX. It is not good practice. The only time a RX should be on with the TX turned off is when checking a failsafe (if fitted) is set up and working correctly.

Gary.

[DickyD]

Turn the Rx on first in my boats and the sound modules go barmy 

[John W E]

The transmitter that I only had one mega problem with and it cost me dearly was a Sanwa Conquest 40 mgz FM mark II - for some reason it didnt like Electronize speed controllers, it didnt matter which way I switched it on - TX/RX first - the relay in the speed controller used to clatter in and out for about 30 seconds and that was even with all the radio gear on the bench.  Aerial stretched out away from the other components.   It cost me dearly because I had upgraded the Electronize speed controller with higher output power transistor and also upgraded the track circuit for the output stage (soldered 30 amp copper wire over the top of the track) I was going to do some serious amperage with this one, but I didnt upgrade the relay and eventually it welded the contacts in the relay together - MELTDOWN 

aye
john e
bluebird

[Circlip]

     Just as you had problems with your set up John, I am only relating from MY experience albeit from a FLYING
      point of view. NOT relevant from a sailing point you may say but I WAS nearly grounded by a fellow 'Modeller', I WAS
      present when a 72" 61 powered missile destroyed itself, bad enough, but this was in the side of a CARAVAN, no
      NOT the pilots fault but some illlegitimate person turning on an illegal transmitter, but no consolation if someone in
      the caravan had been injured. We are ALL blighted if anyone outside the hobby is injured, on the SWAN thread,
      if one of the dammed things was injured by a 'toy boat' just imagine the furore from the tree huggers, the fact that
      you suffered damage to YOUR model doesn't count to them - it's a one way street and WE should know better.
           I can't comment on the modern bells and whistles gear as my models just go left and right and forwards and
      backwards (and  some up and down) using the ancient technology of Messrs REMCON & SANWA on27megs AM,
      if it ain't broke don't fix it, and no I haven't seen ANY manufacturer state RX before TX but with MY gear Ive only
      had 1 near miss.
           Back to servo question, can you explain 'Digital'?

                 Ian

 


     

[sheerline]

I always range check my gear especially before flying and would do the same with any model... especially anything powered by gloplug motor. The method I use is a general guide to the radio's performance and after having checked that no-one was on my designated frequency and before starting the motor, I would fully retract the tx aerial turn on the Rx and perform a full function test of the gear, I would then take the TX, with its retracted aerial and walk away from the model.
 With the greatly reduced range of the tx, I knew how far I could go before glitching set in due to the weakened signal and this gave me an indication that the radio gear was sensitive enough to use. If the gear began glitching early on in this proces it indicated a number of possibilities... either there was a range problem with my gear, there was a possibility that someone was on a frequency close to mine ( or standing close by with a tx switched on) or that there may be someone with one of those horrid little off the shelf models which doesn't seem to conforn to normal frequency regs. Either way, I would seek out the cause before ever starting my motor or releasing a model.
This method has always stood me in good stead and there have been a couple of occasions when my gear has been dicovered to be faulty with an RX range problem which would have had disaterous consequencies had I not first carried out this proceedure .
I should add, this process takes a very short time to carry out and a TX should never be run for prolonged periods with its aerial retracted. Doing so de-tunes the output stage and causes it to draw more current which can damage the output transistor but for these short term checks, it is absolutely fine.
Chris 

[malcolmfrary]

   

Back to servo question, can you explain 'Digital'?

Have a look at
   http://www.futaba-rc.com/servos/digitalservos.pdf
It seems that they are a drop-in replacement, having a narrower deadband and tighter resolution at the expense of higher current consumtion and more expense.  In the same way that ESCs have gone from a bucketful of components to resolve a power setting to a small computer chip, the same sort of job has gone on inside the servo case.  They use the same motor, gearing and feedback pot, and respond to the same signal in the same way.
Eventually, because of the reduced component count, they might result in smaller and cheaper servos, but I wouldn't hold my breath.

[Circlip]

  Thanks Malcolm, person i originally requested has gone sulky poo, but hey ho. These things won't fit my good old
  centre tapped REMCON, but they might fit the Sanwa mini two and RCME FM. I couldn't understand why the cheapest
  of the 'old' servos were in the region of 10£ and the new 'digitals start at 99p on Fleebay. OK things have become cheaper
  due to advanced electronics, - I still have some original red spot transistors that were a pound apiece back in the 50s, but
  even what I class as standard sized units are still more than the 'Digital' ones.
   Thanks for info.