Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: SunnyBob on April 16, 2012, 01:37:09 PM

Title: steering issues
Post by: SunnyBob on April 16, 2012, 01:37:09 PM
I have a steering issue on the boat, looking for a genius to cure it for me  {:-{ %%

i have the action electronics P94 esc, which gives proportional power on the rudder, to allow faster turns. This works well (usually) If i go go full ahead and hard right rudder, the boat will turn 360 circles continuously in about a 3 meter diameter. this is only 3 times the boats length so I'm happy with that.

BUT.... if i go full right rudder only, the boat turns with a slight backwards movement. If while on full right rudder I go full speed forwards, the boat goes backwards faster while turning.
If I go forwards first, then right rudder, it all goes as it should.
Any suggestions? <:( <:(
Title: Re: steering issues
Post by: deadbeat on April 16, 2012, 05:01:27 PM
I'll throw this into the melting pot for discussion.

Is the angle of throw of the rudder the same for port and starboard, aim for around 35-40 degrees or so. It seems the blade of the rudder is acting as a brake and the wash reflecting back giving a backward movement.

Is it a single screw boat? the direction of rotation of the screw will also affect the turning performance of the boat, one way will always turn better than the other. A problem not really expereinced with twin screw ships.
Title: Re: steering issues
Post by: barriew on April 16, 2012, 05:29:59 PM
Is it a single screw boat? the direction of rotation of the screw will also affect the turning performance of the boat, one way will always turn better than the other. A problem not really expereinced with twin screw ships.

The fact that he is using the P94 dual ESC and mixer answers that one O0

It could be that the two motors are not evenly matched, or that one prop shaft is binding.

Barrie
Title: Re: steering issues
Post by: Netleyned on April 16, 2012, 05:42:00 PM
http://www.action-electronics.co.uk/pdfs/P94.pdf

Just in case you have lost the instructions Bob

Ned
Title: Re: steering issues
Post by: John W E on April 16, 2012, 06:20:09 PM
hi there Bob

It sounds as if you may have the mode switches inside the P94 set up wrongly.   This is because your model should literally turn on the spot - when you advance the throttle stick just past neutral and apply either 'full right stick' or 'full left stick'. 

The other possibility is you may have your props rotating in the wrong direction.  As you look at the model from the back - your starboard prop should turn clockwise so that it goes forward.   Your port should turn anticlockwise to go forward.

Maybe a phone call/email to Mr ACTion man might be the best option - Dave will help you I am sure.     Better to speak to the butcher rather than the block as they say  O0 O0

Good luck with that

aye
john
Title: Re: steering issues
Post by: Netleyned on April 16, 2012, 06:49:51 PM
That is why I gave Bob a link to the instructions

Ned
Title: Re: steering issues
Post by: SunnyBob on April 16, 2012, 09:50:54 PM
I went through the instructions a couple of times, thought I had it right, but I;ve been known to be wrong  <:( <:(

The turning circle is VASTLY improved over what it was (used to be about 20 meters for a 360). it will now turn at speed, with an impressive bow wave.
I've fitted larger rudders, new shorter shafts which make the props only 4mm from the hull (they used to be over an inch away). I took a lot of care to ensure the shafts had the same rotational friction.
They are paired props, and I cant swear to which way they are fitted, so I'll go check that in the morning when I rad the instructions again.

I noticed I had to move the transmitter trim a long way over from centre to get both motors to stop at idle.

Rudders are matched in size and position, servo is centered at dead ahead.
Strange thing is it works fine on left rudder /full ahead. it only misbehaves on right rudder.
Title: Re: steering issues
Post by: john s 2 on April 16, 2012, 10:09:55 PM
With regard to the motor balencing. The later p94 was programmed to eliminate this.Please see actions website for more infro. John.
Title: Re: steering issues
Post by: SunnyBob on April 17, 2012, 09:29:12 AM
ok, I know I'm always saying it, but i dont always practice it... "when all else fails, read the instructions!"  <*< >>:-(

i fitted the the P94 about 6 months ago, but due to the work on the shafts, didnt actually set it up other than the dip switches.
I now see I have a trim pot to play with. :embarrassed:

Dont know what you would consider the "later version", mine must be 2 years old now, but this is the first time its been used.

So what mode do you think is mosr realistic for a 40 ft cabin cruiser? turning in its own length? or the inboard motor stopped?
Title: Re: steering issues
Post by: ACTion on April 17, 2012, 09:40:00 AM
ok, I know I'm always saying it, but i dont always practice it... "when all else fails, read the instructions!"  <*< >>:-(

i fitted the the P94 about 6 months ago, but due to the work on the shafts, didnt actually set it up other than the dip switches.
I now see I have a trim pot to play with. :embarrassed:

Dont know what you would consider the "later version", mine must be 2 years old now, but this is the first time its been used.

So what mode do you think is mosr realistic for a 40 ft cabin cruiser? turning in its own length? or the inboard motor stopped?

Mode 4.
DM
Title: Re: steering issues
Post by: DickyD on April 17, 2012, 09:43:12 AM
Mode 4  :-))

Sorry Dave, put it down to my age. :embarrassed:
Title: Re: steering issues
Post by: John W E on April 17, 2012, 01:01:36 PM
hi sunybob

can you tell us what make and model  of transmitter and receiver you are using in the model which the p94 is fitted in ?

aye john

 

 
Title: Re: steering issues
Post by: DickyD on April 17, 2012, 01:16:39 PM
The original P94 had problems with the cheap 2.4 systems.

This is the reason Dave has brought out a new plug and play P94 which works well with the cheap systems.
Title: Re: steering issues
Post by: ACTion on April 17, 2012, 01:53:26 PM
P94 Autoset was introduced last October. We can supply an upgrade PIC chip for any P94 (just unplug the old one and fit the new one into the socket) or we will undertake to fit one if the owner doesn't feel happy about doing it him/herself. Contact us for a price (mainly postage).
That said, I think Bob's problems are more down to slight differences between the two motors e.g. brush timing. The trimmer R1 will not do anything to solve that situation.
Dave M
Title: Re: steering issues
Post by: SunnyBob on April 17, 2012, 04:56:29 PM
I'm a really busy man at the moment, over the next couple days I'll get all this sorted and come back to you.
thanks
Title: Re: steering issues
Post by: ACTion on April 17, 2012, 06:38:39 PM
I'm a really busy man at the moment
You reckon? Since last Friday I've built 30 x P94s, 112 x P95s, 10 x P103s and 10 x P104s - and we're still short of certain stock units for the Coalville show! I wonder what I'd do if I had time for a hobby................... 8)
Dave M
Title: Re: steering issues
Post by: DickyD on April 17, 2012, 07:27:45 PM
You reckon? Since last Friday I've built 30 x P94s, 112 x P95s, 10 x P103s and 10 x P104s - and we're still short of certain stock units for the Coalville show! I wonder what I'd do if I had time for a hobby................... 8)
Dave M
Spend some of that money you're earning.  (http://i124.photobucket.com/albums/p8/DickyD_photos/Smileys/ROFL_C1.gif)
Title: Re: steering issues
Post by: ACTion on April 17, 2012, 08:12:08 PM
The kids do that for me. Never believe that they stop costing money when they leave home. The "loans" just get bigger (by a factor of about a hundred).
DM
(Sorry for drifting off topic, Bob - you can have your thread back now)
Title: Re: steering issues
Post by: SunnyBob on April 18, 2012, 10:33:34 AM
thread hijacks are a good thing  :-))
I'm on a motorcycle forum and some newbie came along last week, and on his FIRST post, and moaned about the number of thread hijacks on the site. Can you believe it? he wanted first class advice for free, and then moaned when all the regulars had fun at each others expense.
The thread is still ongoing, its passed 200 replies, only about three of which were replies to him, and they all told him where to go if he didnt like it.
 %% %% {-) :-) :-)
Title: Re: steering issues
Post by: RAAArtyGunner on April 18, 2012, 10:44:43 AM
thread hijacks are a good thing  :-))
I'm on a motorcycle forum and some newbie came along last week, and on his FIRST post, and moaned about the number of thread hijacks on the site. Can you believe it? he wanted first class advice for free, and then moaned when all the regulars had fun at each others expense.
The thread is still ongoing, its passed 200 replies, only about three of which were replies to him, and they all told him where to go if he didnt like it.
 %% %% {-) :-) :-)

SunnyBob,

That makes Mayhem downright tame and civilized, where's the Mayhem???? %) %) %) {-) {-) {-)
Title: Re: steering issues
Post by: SunnyBob on April 18, 2012, 02:51:18 PM
ok, David shamed me into finding some time to do more testing. :embarrassed: O0

conclusion 1;  I dont like mode 4 on the esc. its too similar to what I had before, great big turning circles.

conclusion 2;  I do like mode 3. Mode 3 is good. I can get a 3 meter 360 under full power, and I can steer to berth pretty good on the rudders alone.

conclusion 3  There is something wrong somewhere....
with the rudder on full right, the throttle works the motors, but makes the boat go backwards, regardless of whether I'm pushing forward or back.
This does NOT happen on left rudder, that works fine.
I've checked the props, they are on reversed, I shall change them over when I've got time  ;)
The motors dont start together, there is a slight lag on the right hand motor, but only a fraction of a second. But I cant see either of them being the culprit, so help please......
Title: Re: steering issues
Post by: John W E on April 18, 2012, 02:56:04 PM
hi sunybob

can you tell us what make and model  of transmitter and receiver you are using in the model which the p94 is fitted in ?

aye john

 

 
pleas tell
Title: Re: steering issues
Post by: john s 2 on April 18, 2012, 04:12:21 PM
Mode 4 should work well if full rudder is given your boat should turn in its own length. Less rudder gives a proportional turn like mode 3. It does seem that your set up needs looking at . Which of course your doing. Please as asked let the lads know what rc your using. John.
Title: Re: steering issues
Post by: triumphjon on April 18, 2012, 04:26:01 PM
maybe a pic of the model of boat would also help us in working out the problem ?  are the props counter rotating ? have you tried running without the mixer , ? is the boat running straight on the motors ?  i run regularly two model fairey marine cruisers , one a huntsman the other as the spear , the spear is fitted with an independant esc per motor but both linked on a Y  lead to my rx , turning at full rudder on full speed i get a 360 in around  three lengths of the model , this improves dramatically at a slower speed !
Title: Re: steering issues
Post by: SunnyBob on April 18, 2012, 04:40:40 PM
http://i637.photobucket.com/albums/uu99/sunnybob_photo/0033.jpg

cant get the pic to show here, so heres the link (I hope) of all the internals of the boat.

The TX is a cheap Hi Tec 2 channel, but it worked fine before this rewire.
The boat in question is the one in the sig pic, 3ft cabin cruiser.
boat runs straight on full ahead.
Title: Re: steering issues
Post by: Bob K on April 18, 2012, 05:56:43 PM
A few months ago I fitted a P94 into my WW1 destroyer.  It turns beautifully in Mode 4 considering it is 900mm long but only 89mm beam.
See video clip  http://www.youtube.com/watch?v=7Cl_HNu06WY (http://www.youtube.com/watch?v=7Cl_HNu06WY)
Set up is a doddle compared with trying to equalize neutral points on separate ESC's.

I have just commissioned a second P94 on my WW1 cruiser, also in Mode 4.  The 'inside' prop progressively slows as helm increases, until near full rudder it stops, and in identical manner left or right.  It seems that at low throttle settings the effect increases proportionally, so that lower angles of rudder stop the inboard prop - which is exactly what I need for low speed maneuvering long thin ships.

This assumes you have L & R handed props, rotating outwards at the top when going ahead, and that rudder throw is equal both sides.

Mode 3, which speeds up one prop whilst slowing the other, would be more suited to tugs ferries and fishing vessels.
Title: Re: steering issues
Post by: John W E on April 18, 2012, 06:48:13 PM
hi there

To be honest it sounds as if its the cheap 2 channel transmitter at fault you know; basically on cheaper sets the channel separation between 1 & 2 isnt very good on some of them.

I have had this sort of problem on a more expensive set - a futaba 6A - unless of course - his HiTec cheap set has a memory set in it (which I very much doubt) this could also cause the problem.

The cheaper sets are brilliant when they are working; a standard servo and perhaps 1 speed controller, can become a right pain in the butt when you put something in the system that can think.

aye
john
Title: Re: steering issues
Post by: triumphjon on April 18, 2012, 07:45:21 PM
was the radio in the same boat before you installed the P94 ?  do the props rotate in the same direction , or oposing directions ?
Title: Re: steering issues
Post by: Tug-Kenny on April 18, 2012, 07:48:25 PM
http://i637.photobucket.com/albums/uu99/sunnybob_photo/0033.jpg

cant get the pic to show here, so heres the link (I hope) of all the internals of the boat.


Hi SunnyBob

Here is your picture that I've dragged into submission.      %)

regards
ken





Title: Re: steering issues
Post by: SunnyBob on April 18, 2012, 09:34:26 PM
was the radio in the same boat before you installed the P94 ?  do the props rotate in the same direction , or oposing directions ?

the whole system worked normally before I fitted the P94, I had a single esc controlling both motors. the props are contra rotating, but at the moment are going the wrong way according to the experts. i will shift them soon.

If it means buying another transmitter/ receiver, then I'm just going to live with it, as I have far too much time and money in this boat already. It is not used often enough to justify more hundreds of pounds.
Apart from this one annoying foible, everything else is fine.
Title: Re: steering issues
Post by: John W E on April 18, 2012, 10:18:43 PM
Hi SunnyBob
last question   if you put the rudders full over to port does the PORT motor slow down or stop and the Starboard motor speed up ?

aye
john
Title: Re: steering issues
Post by: triumphjon on April 18, 2012, 10:40:24 PM
my own models operate contra rotation , when veiwed from the stern  the port shaft rotates anti clockwise , starboard running clockwise .
Title: Re: steering issues
Post by: ACTion on April 19, 2012, 10:14:18 AM
It sounds to me as if you have damaged the P94 somehow in as much as one motor does not reverse when commanded to. I suggest you try testing the unit in Mode 1 (Tank Steering) and moving the sticks independently. The throttle stick will then control just one motor and the rudder stick the other. The relays should click when you move the sticks through their central position and each motor should reverse. If one does not then it's safe to assume that the unit is damaged and should be returned for repair. The cost of this would be mainly postage.
As with any questions affecting ACTion units I would be grateful if customers would contact us initially i.e. before posting questions on Internet forums (fora?). It saves time and avoids confusion.
Dave M
Title: Re: steering issues
Post by: SunnyBob on April 19, 2012, 11:26:10 AM
testing as follows. all viewed from rear of boat
forward stick =right prop clockwise left prop anticlockwise.

in tank mode= left stick works left motor. right stick works right motor AND rudders, Is this ok?

in mode 4 = rudder stick alone has no affect on motors. throttle then either rudder makes the outer motor stop each time.

in mode 3= right rudder only and both motors turn anticlock. left rudder only and both motors turn clock.
right rudder then forward and right changes to clock.
left rudder then forward =right stops and reverses.
forward then right rudder=left  stops and reverses.

I'm completely dizzy now, going for a lie down  %% %%

Dave, at this stage, and even now, i dont know what if anything is at fault. as Colin says, it may well be my cheap transmitter. this kind of forum is made for this kind of question, many folk can help me resolve )ar at least diagnose) the problem even if it comes down to user error. ;D :embarrassed:
Title: Re: steering issues
Post by: Circlip on April 19, 2012, 11:54:15 AM
Quote
As with any questions affecting ACTion units I would be grateful if customers would contact us initially i.e. before posting questions on Internet forums (fora?). It saves time and avoids confusion.

  C'mon Dave, it ain't arf as much fun as watching the experts muddy the water. You'll be telling us to RTFM next  :-)) {-)

  Regards  Ian.
Title: Re: steering issues
Post by: John W E on April 19, 2012, 11:55:09 AM


Hi sunny bob

 

Does your transmitter have a servo reverse switch on it? If so, reverse the rudder servo over and try this full ahead and full left rudder.

 

The port or left motor should slow down/ stop or even go into reverse AND the starboard motor should speed up going full ahead

 

aye

john

 
Title: Re: steering issues
Post by: ACTion on April 19, 2012, 02:34:28 PM
Bob
I am sending you a private message.
Dave M
Title: Re: steering issues
Post by: malcolmfrary on April 20, 2012, 10:41:47 AM
Just a thought, are the servo reverse switches both set for "N" rather than "R"?  I've been caught out by that a few times when dealing with gear that's cleverer than me.
Title: Re: steering issues
Post by: SunnyBob on April 20, 2012, 04:13:48 PM
I've been doing a lot of checking with Dave,
I had the motors wired crossways, and the props the wrong way round.  :embarrassed: :embarrassed: :embarrassed:

Fixed all that, and there is a big improvement. the only issue now appears to be my TX, if I apply right rudder BEFORE throttle, the boat goes backwards, regardless of throttle direction. If i apply throttle first and then rudder, all works as it should.

I'll look for a better TX, but I'm just not prepared to spend too much on this. the model just doesnt get enough useage to warrant big money.

On a connected issue... the rudders only move 30 degrees from centre, is this normal? I thought they should move 45 degrees.
Title: Re: steering issues
Post by: john s 2 on April 20, 2012, 10:46:16 PM
Rudder movement can be adjusted by sevo link ratio. Put simply by altering the hole used by the link bar the movement (throw) can be altered. To much rudder movement can also effect steering.John.
Title: Re: steering issues
Post by: Bob K on April 20, 2012, 11:41:39 PM
I had the motors wired crossways, and the props the wrong way round.

Sunnybob:  That is so easily done, especially if this is your first twin shaft set up.  I bet most (if not all) of us have been there, and learned from it.
Getting two motors to run in opposite directions the right way round, and getting the correct prop on each shaft, does take some headscratching at first.
The bath makes a great test tank  :-))

Personally I have my rudders turning 45' each side.  Seems to improve low speed handling.

Not sure what's happening with your Tx.  I have a Planet T5 which cost around 40 but drives several ships with just an extra 14 receiver for each additional boat.  
Title: Re: steering issues
Post by: SunnyBob on April 21, 2012, 06:38:33 AM
ok, I'll move the rudder link closer in on the servo arm. So 45 degrees is maximum?

My Tx is a second hand hi tec I bought off ebay for 15 about 5 years ago. I dont think I had this problem before, but like I say, This model doesnt get much use. The only reson I've done all this work is that the wooden planking kept splitting apart with the summer heat here. So I've fibreglassed inside and out, and am now waiting for the august heat to see if this is still going to split.

Does anyone have a spare Tx for sale at around 20-30?
Title: Re: steering issues
Post by: Bob K on April 21, 2012, 07:08:43 AM
ok, I'll move the rudder link closer in on the servo arm. So 45 degrees is maximum?

Most of your streering will be with quite small amounts of rudder.  Around 45' for low speed tighter turns.  Much above 45' and the rudder will not do much, except act as a brake.

On your Tx.  If if worked before then it should work with your new set up, provided your boat is wired up correctly.  Suggest leave it in Mode 4.  Left stick up/down is throttle.  Right stick left/right is rudder.  The P94 is an excellent unit, with detailed and clear instructions.

On Ebay right now is a Planet T5 system with current bid at 27.99
http://www.ebay.co.uk/itm/PLANET-T5-2-4Ghz-PLUS-2-6CH-RXs-/270957824833?pt=UK_ToysGames_RadioControlled_JN&hash=item3f16584b41 (http://www.ebay.co.uk/itm/PLANET-T5-2-4Ghz-PLUS-2-6CH-RXs-/270957824833?pt=UK_ToysGames_RadioControlled_JN&hash=item3f16584b41)
Title: Re: steering issues
Post by: SunnyBob on April 21, 2012, 05:27:35 PM
about 15 minutes after posting that, i realised I need a longer servo arm to get more movement, not shorter.

i cant see an easy (cheap) way out of this, i think I'll just live with the problem this year. if the hull gets through the summer without cracking open, i might get back into it next winter,
Thanks for all the help.  :-))
Title: Re: steering issues
Post by: malcolmfrary on April 22, 2012, 10:25:45 AM
It is simple enough to make an extension for the servo arm, often it is equally easy to move the pivot point in at the tiller arm. 
Best not to overdo it, though.  When you increase the travel by adjusting levers, there is always the chance of the system toggling over.  Amusement and embarrassment are generally equally distributed between onlookers and owner.
Title: Re: steering issues
Post by: SunnyBob on April 22, 2012, 06:23:23 PM
got the steering sorted nicely now, had to increase the servo arm by about 10mm. rudders now go to 45 degrees, and the boat actually turns in its own length on just rudder.
 :} :} :} {-) {-) %% %% %% :-)) :-)) :-))

Unfortunately the battery died before I could do full power turning trials. so thatll be a few days now as I'm back to work tomorrow.

Its just this right rudder overide direction problem to solve.

I found an exact same Tx  (Hi-tech ranger 2) (new) for 25. But i just felt there was too much risk of having the steering fault trandsfer to the new unit.