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>> Home > Forum > Electrical Related > Twin motor control problem
Twin motor control problem
(1774 views)
Author Message
John
(Fleet Admiral!)





Forum Posts: 104
16th Oct 2017 21:42  
>> Permalink
mdlbt.com/34594

Twin 550 brushed motor Pt 109. Motors run fine on the bench (forward and reverse). When in the water the boat goes only in reverse despite the direction of the stick. Have tried another radio and have the same problem. The motors have independent viper ESC’s. Originally it used a cable splitter and then used a mixer and the problem remains any ideas?


Happy sailing.

John.
Berty
(Seaman)





Forum Posts: 3
17th Oct 2017 11:29  
>> Permalink
mdlbt.com/34626

With twin motors,that usually run in alternate directions...I e. One clockwise...one anti clockwise you need 2 different props...one clockwise..one anti etc...are you using the correct props ?

John
(Fleet Admiral!)





Forum Posts: 104
17th Oct 2017 16:55  
>> Permalink
mdlbt.com/34641

Hi Berty,

the props and direction of rotation are correct. The motors only rotate in one direction when in the water. They are fine on the bench.

John,


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
17th Oct 2017 17:31  
>> Permalink
mdlbt.com/34647

Interesting.
What radio system are you using?
Can you try just using one motor and ESC at a time to see if the problem is still present?
You mention a mixer but assume you are now connecting the ESCs direct to the rx?


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
17th Oct 2017 18:08  
>> Permalink
mdlbt.com/34649

Hi Dave,

I have used two radio systems Planet and Spektrum to see if that was the problem. The problem is the same with both. If you use either ESC and motor there is no problems. The esc were connected direct to the rx and are now connected via a mixer unit. I can not understand how it is fine on the bench but not in the water. I have tried lifting the transmitter to see if is about the height and walking away to see if it distance. Back to the water tomorrow with new ESC's.

John.


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
17th Oct 2017 18:43  
>> Permalink
mdlbt.com/34650

Is the mixer connected to the rudder. When you test on the bench does it work OK if you move the rudder stick fully both ways?.
I suspect the mixer is perhaps the culprit. What mixer unit are you using?
What is your power set up re batteries? Are they all fully charged?


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
17th Oct 2017 20:29  
>> Permalink
mdlbt.com/34653

The mixer was used because the problem was present with a Y cable splitter. The mixer is Mtroniks WTail mixer and is connected to the rudder. Everything is fine on the bench even full both ways. It is powered by a fully charged 11.1v Lipo


Happy sailing.

John.
jarvo
(Fleet Admiral!)





Forum Posts: 466
17th Oct 2017 20:54  
>> Permalink
mdlbt.com/34656

Hi John, a thought, have you disconnected one of the red leads from the esc's? might be getting duff feedback to the receiver
Mark


Etherow Model Boat Club
Berty
(Seaman)





Forum Posts: 3
17th Oct 2017 22:22  
>> Permalink
mdlbt.com/34674

Hi John

I think its time for the bath test......half fill bath......run motors with model held up in air to make sure motors are running correctly.....lower model half way into bath props half in half out of water.... check motors still running correctly...then fully into water....motors must still run correctly.....they can't reverse when they smell water !.....can they?


Can we see photo of props and rudders....the solution may lie elsewhere

I love this problem it's a good un !l

Berty

John
(Fleet Admiral!)





Forum Posts: 104
17th Oct 2017 22:23  
>> Permalink
mdlbt.com/34675

Hi Jarvo,

Yes one red lead has been disconnected from an ESC.


Happy sailing.

John.
John
(Fleet Admiral!)





Forum Posts: 104
17th Oct 2017 22:27  
>> Permalink
mdlbt.com/34676

Hi Berty,

That is what I will be doing at the lake tomorrow. I have found the problem impossible! So in the absence of anything else will try a new esc! How can something change when it is in the water! There are no connections to the shafts or external in the water! Anyway it will be sailing backwards at Bury tomorrow.


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
17th Oct 2017 23:37  
>> Permalink
mdlbt.com/34687

Please let us know what happens


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
18th Oct 2017 00:39  
>> Permalink
mdlbt.com/34690

Yes I will give you an update tomorrow.


Happy sailing.

John.
reilly4
(Lieutenant)





Forum Posts: 14
18th Oct 2017 03:14  
>> Permalink
mdlbt.com/34695

Hi John,
I have a several MTroniks ESCs.
If you have the Plug & Play type, then when you first start you need to move the stick forwards and then back. I find that sometimes they refuse to go forward and prefer reverse when the stick is moved forward, so I move the stick backwards first. This usually works (although I don't know why).
I do not use the BEC (my choice).
I have also had issues with using a single 30Amp Tio ESC running two 12V motors via the single ESC in my Vosper MTB. No answers from MTroniks.
Regards

RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
18th Oct 2017 13:09  
>> Permalink
mdlbt.com/34703

Hi John, maybe some clues here! "Hints & Tips - FAQs"
You may need to make some adjustments on your TX; Failsafe, EPA ...
I use Viper Marine 10s without any bother at all😉
Still don't quite understand why it works dry but not wet🤔 UNLESS, poor antenna installation or motor suppression (interference?) is activating the Failsafe. If still set as 'standard' (i.e. for aircraft) on the TX this will most probably be 'Full Back' and needs resetting to the mid point.
Most (only?) logical explanation I can see, and changing the ESC won't cure it - but al least you'll have some spares 😉
Good luck, Doug 😎


Attached Files - Click To View Large


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
reilly4
(Lieutenant)





Forum Posts: 14
18th Oct 2017 13:46  
>> Permalink
mdlbt.com/34705

Another thought - The main difference between the bench and the water is the load on the system - ie increase in amps.
This load may cause the reduction in signal and into failsafe? What size propellers are in use?
Maybe a test with smaller props.
I would also test without the BEC.

RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
18th Oct 2017 13:54  
>> Permalink
mdlbt.com/34706

Hi reilly, Possible, but I would only expect the motor load current to decrease the RX sensitivity if the battery is almost flat and the extra load pushes it below the failsafe voltage limit. John has already confirmed that the battery is/was fully charged.
Cheers Doug 😎
PS testing without BEC is a good idea as it would confirm or eliminate the possibility that the RX supply voltage is collapsing and causing a Failsafe condition. I prefer separate RX batteries anyway, fewer surprises😲! Except in the smallest Plastic magic projects where weight is critical.


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
18th Oct 2017 20:59  
>> Permalink
mdlbt.com/34732

Thank you all,

The boat did not sail today due to an unrelated problem. Plan is to fit the new ESC's which arrived today and make sure they are correctly programmed, also considering losing the mixer as it did not alleviate the problem. It will sail next Wednesday and I will give you an update! Thanks again for all your help.


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
18th Oct 2017 21:21  
>> Permalink
mdlbt.com/34737

Good, get rid of the mixer until the basics work! 👍
I'm pretty sure the snag is more in the antenna position and/or motor suppression - duff capacitor? - causing a Failsfe condition.
Good luck, Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
Dave M
(Fleet Admiral!)





Forum Posts: 1398
18th Oct 2017 21:27  
>> Permalink
mdlbt.com/34738

John
As you are using 2.4Ghz radios there is quite a long delay in the binding between Tx and Rx. The ESCs also perform a set up and I have noticed that this is often quicker than the radio. As a result the ESCs have no signal and can revert to a failsafe state.
If you have correctly set up the ESC with the tx then it should retain this setting unless you press the set up button whilst the lights are flashing.
I suspect this is at the root of the problem.
To restore the settings to your set I suggest you use a separate rx battery, centre the throttle stick and trim and get the Tx/rx working together. Then switch on the ESC and whilst the lights are flashing press the set up button and move the throttle stick full forward (solid green) then full reverse (solid red) return to neutral solid red/green.
If you now switch off the esc and rx battery and switch back on the ESC should have solid red/green light showing.
Repeat with the other ESC and test.
Switch off and connect both escs via the Y lead. You can use one ESC to provide the rx power but do disconnect one red lead.
Centre the tx throttle and trim and make sure you switch on the ESC with the BEC connected first.

Hopefully both ESCs will now have solid red/green leds.

I use three Mtronic ESCs with my RMS Olympic and had a very similar problem.

I suspect the change from bench to water is more to do with stick/trim alignment and longer binding time due to other 2.4 Tx working in close proximity at the sailing site.

I look forward to hearing your efforts next wednesday - hopefully the next hurricane will have passed by then.


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
18th Oct 2017 22:27  
>> Permalink
mdlbt.com/34744

Thanks Dave and Doug, I will make sure the ESC's are set up and if the hurricane has passed I will look forward to a nice day sailing 😁


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
19th Oct 2017 00:51  
>> Permalink
mdlbt.com/34765

Good luck John 👍
The 'hurricane' brought us a superb Indian Summer here in south Germany, blue skies and 25°C in Munich. 😊 Should last until Saturday, then the rain is back 🤔 It really is an ill wind that blows nobody any good!
To avoid the binding timing problem Dave describes above use a separate RX batt and disconnect BOTH BECs!! Then only switch on the ESCs after the TX is bound with the RX.
Several RC module manufacturers warn against BECs, e.g. Action Electronics! Happy sailing, Cheers Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
tomarack
(Commander)





Forum Posts: 23
19th Oct 2017 12:15  
>> Permalink
mdlbt.com/34784

Hi,
I have to say - I use a simple V-tail mixer only, and ESC at the basic setting, the transmitter => Throttle and Ail only(right stick).
I tried to connect Rudder servo to this design, but I could not adjust it, the servo behaved "non-standardly".
That's why I have it connected to the usual rudder channel nr 4 (left stick).
One more important thing ... check the settings of the transmitter, especially the mixes that are sometimes pre-programmed from the factory.
It is recommended to clear the transmitter memory first, and then set your own values. It usually helps ...
I use the power supply of the receiver from a single source via an external BEC, powering motors using Y cables to ESC,from the same source as BEC ( gel Aku 12V).I had setup problems too - I finally found that one ESC was defective. after replacing both ESC no problems.


Main principle: if It is not broke - do not repair It !
tomarack
(Commander)





Forum Posts: 23
20th Oct 2017 15:53  
>> Permalink
mdlbt.com/34811

hi,
I found on the net examples of electrical connection twin ESC.
regarding the connection of the rudder servo with the Y cable to one of the branches for the ESC, it made me problems when reversing , and that's why I gave the rudder separately


Attached Files - Click To View Large


Main principle: if It is not broke - do not repair It !
John
(Fleet Admiral!)





Forum Posts: 104
20th Oct 2017 22:40  
>> Permalink
mdlbt.com/34813

Thanks Tom.


Happy sailing.

John.
Haverlock
(Fleet Admiral!)





Forum Posts: 423
21st Oct 2017 08:32  
>> Permalink
mdlbt.com/34819

it depends how much work and thought your willing to put in but for anyone with a bent for such things an arduino can " read" RC signals and with a suitable add on board control servos so should also be able to control ESCs thus you can tailor the drive to your requirements including the forward on one drive and reverse on the other for tight turns.


"that's not a bug its just an undocumented creature."

Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
Haverlock
(Fleet Admiral!)





Forum Posts: 423
22nd Oct 2017 05:50  
>> Permalink
mdlbt.com/34845

I just had what is probably a stupid thought but its worth asking. Is the RX located below the water line? 2.4GHz does not propagate through water so you may be going into a fail safe mode.


"that's not a bug its just an undocumented creature."

Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
22nd Oct 2017 05:58  
>> Permalink
mdlbt.com/34846

Hi Haverlock, not stupid at all 👍 That's exactly what I meant with poor antenna installation. Cheers Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
22nd Oct 2017 19:47  
>> Permalink
mdlbt.com/34861

The Rx is above the water and has been tried in 3 positions.

John.


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
22nd Oct 2017 20:47  
>> Permalink
mdlbt.com/34863

Hi John
Probably a bit too windy to-day but did you manage to do any more tests on the water?


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
22nd Oct 2017 21:49  
>> Permalink
mdlbt.com/34867

Hi Dave, no it will be Wednesday. I will let you know.


Happy sailing.

John.
Mzee
(Chief Petty Officer)





Forum Posts: 9
24th Oct 2017 14:46  
>> Permalink
mdlbt.com/34926

I wanted total motor control on my large, heavy twin screw harbour tug. The rudder is pretty useless serving only as a sort of trim tab so I went the simple route: Each (brushed) motor has its own ESC and independent power supply so left and right Tx sticks control their appropriate motor. By doing this I am able to have one full ahead, the other full astern, to turn on the proverbial sixpence or for slick docking alongside

John
(Fleet Admiral!)





Forum Posts: 104
29th Oct 2017 18:08  
>> Permalink
mdlbt.com/35136

The problem persists! Another week, to try a few new things.


Happy sailing.

John.
John
(Fleet Admiral!)





Forum Posts: 104
1st Nov 2017 20:44  
>> Permalink
mdlbt.com/35216

Another week and the problem remains despite trying different options. Plan is to buy two new ESC which do not require programming or setting up. The good old blue metal ones! Will let you know what happens of course.


Happy sailing.

John.
reilly4
(Lieutenant)





Forum Posts: 14
1st Nov 2017 22:20  
>> Permalink
mdlbt.com/35220

Hi John,
You have not told us what you have tried. Have you tried just a single motor with one ESC and no BEC?

John
(Fleet Admiral!)





Forum Posts: 104
1st Nov 2017 22:47  
>> Permalink
mdlbt.com/35221

Sorry Reilly, A single motor with one ESC works perfect, as does the other motor with the other ESC. The Viper ESC's have been set up as a pair in the boat and individually on the bench. The problem remains only when the boat is in the water. So I am going to try ESC’s which do not require any set up and see next week.


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
2nd Nov 2017 01:03  
>> Permalink
mdlbt.com/35223

Hi John
I can see no logical reason why motors that run clockwise and anticlockwise on the bank should not perform the same when in the water. You have confirmed individually each motor works correctly.
If you try one ESC and it works OK in the water, plugging in the other ESC without the motor connected should not make any difference. If so then the only difference is the effect of the props. Is it possibly a reversed ESC motor connection causing the model to only run backwards?


Live long and prosper

Dave
reilly4
(Lieutenant)





Forum Posts: 14
2nd Nov 2017 01:33  
>> Permalink
mdlbt.com/35225

John,
Before you get any more ESCs here are a two basic things to try.
1. At the water's edge (on the stand) start the motors (both). Check their rotation. Then lower the boat into the water and see what happens. Either it should continue in the forward direction or it will stop and then go into reverse.

Separately
2. Plug ESC into one radio channel and plug the other into another channel. This is a test - each ESC will be totally independent. Also we don't want use the BEC.

I have had problems of a similar but slightly different nature with my Fairmile D previously, except that one of the motors would just stop after 15 or 20 seconds. Now I have each ESC running off a separate channel on the radio and the two channels are mixed so there is a master and slave channel and I use the single throttle stick to operate it. It works fine.

Colin T
(Chief Petty Officer)





Forum Posts: 1
2nd Nov 2017 17:20  
>> Permalink
mdlbt.com/35237

John,
I had a problem with my Aerokits Solent lifeboat. What I discovered was that my receiver (I use a Spektrum DX6i) could not continuously feed two ESCs. Alternately the ESCs went into failsafe mode. I eventually solved my problem by binding a second receiver to my transmitter. I now use each ESC, which are Mtroniks Tio Marine 50, on their own receiver. I have retained the BECs on both receivers. This may help you.

RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
2nd Nov 2017 17:52  
>> Permalink
mdlbt.com/35238

Hi Colin, interesting phenomenon!
I also have a DX6 (not i) and several RXs, will test this on one of my twin screw ships.
Cheers Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
2nd Nov 2017 23:13  
>> Permalink
mdlbt.com/35252

Thanks All, I shall give the suggestions a try and update you on Wednesday weather permitting.


Happy sailing.

John.
Haverlock
(Fleet Admiral!)





Forum Posts: 423
2nd Nov 2017 23:24  
>> Permalink
mdlbt.com/35253

just a thought if you reverse the direction of the problem motor out of the water and it reverses when wet does that not fix your problem?


"that's not a bug its just an undocumented creature."

Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
John
(Fleet Admiral!)





Forum Posts: 104
2nd Nov 2017 23:53  
>> Permalink
mdlbt.com/35254

The problem is both motors. For some reason they work fine until they are in the water then they both only go in reverse. It is not the transmitter as I have tried two tx and rx. Not about distance or height. Nothing is connected to the water. Have tried moving the rx. Current thinking is it must be some kind of feedback between the ESC's but that does not explain why it does not do it on the bench.


Happy sailing.

John.
Haverlock
(Fleet Admiral!)





Forum Posts: 423
3rd Nov 2017 00:16  
>> Permalink
mdlbt.com/35255

On the face of it its impossible however since it occurs we must accept reality. So brushed motors how is the suppression? Your statement about nothing connected to the water metal prop shafts and tubes? metal rudder shaft and tube? If you have a multimeter see if one of your prop shafts has a voltage. It has to be some effect of conduction and the prop shafts are the obvious conduit.


"that's not a bug its just an undocumented creature."

Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
Haverlock
(Fleet Admiral!)





Forum Posts: 423
4th Nov 2017 10:11  
>> Permalink
mdlbt.com/35311

Your problem is interesting me one other thought is:- when the boat is out of the water the loading ( current) is way lower than the same motors in the water. It may be possible that the increased current is causing the voltage to " sag" and thus cause all sorts of strange effects. One simple thing you could try is to remove the red lead from the ESC(s) and power the receiver from its own battery. That's the red lead to the RX not the ones to the battery. If you can use a watt meter to read the battery voltage and current draw with the boat in the water.


"that's not a bug its just an undocumented creature."

Sir Terence David John "Terry" Pratchett, OBE (28 April 1948 - 12 March 2015)
John
(Fleet Admiral!)





Forum Posts: 104
4th Nov 2017 20:30  
>> Permalink
mdlbt.com/35330

No voltage on the prop shafts of rudders, it must somehow be related to the increase in the current being drawn when the motors are under load. That is why I was thinking try another type of esc which does not required any setting up. I will let you know what happens Wednesday 😁


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
4th Nov 2017 20:54  
>> Permalink
mdlbt.com/35331

John
From all the info I do not believe the answer lies with the ESC.
When you run on the bench you are viewing both motors and they rotate in both directions as you move the Tx sticks to both extreems.
When you run in the water you are viewing both motors and they rotate in one direction only as you move the Tx sticks to both extreems.
Can you confirm this is the case, please.


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
4th Nov 2017 22:01  
>> Permalink
mdlbt.com/35333

Hi Dave, yes on the bench everything works as it should in both directions. In the water the only direction is reverse. Sometime it can go forward at low speeds for a short period before the reverse kicks in but then only reverse is available at all speeds.


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
4th Nov 2017 22:10  
>> Permalink
mdlbt.com/35334

Hi Dave, I'm inclined to agree, makes no sense!
@ John: can you please finally confirm if you have tried a run without using any BEC?
Looking at all the above with my engineer's analytical view I'm beginning to wonder if the 'at sea' load on a single source battery is causing the BEC voltage to sag which puts the RX into 'Failsafe' mode.
It can't be an ESC Failsafe problem because ESC Failsafe just means All Stop!
Cheers Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
reilly4
(Lieutenant)





Forum Posts: 14
4th Nov 2017 22:16  
>> Permalink
mdlbt.com/35335

Hi John,
Have you contacted Mtroniks about this at all. I have never received any answers to my email queries, but a friend of mine telephoned them with a query and they helped him.
I agree with Dave and Doug too, but you have not yet told us if you have tried with a separate power supply to the Rx instead of the BEC.

John
(Fleet Admiral!)





Forum Posts: 104
4th Nov 2017 22:19  
>> Permalink
mdlbt.com/35336

Sorry, yes I have tried using it without the bec and it made no difference.


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
4th Nov 2017 22:33  
>> Permalink
mdlbt.com/35337

Hmm!🤔
Can you vary the speed when it only runs in reverse?


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
4th Nov 2017 22:44  
>> Permalink
mdlbt.com/35339

That is a very interesting question Doug! and the answer is yes and no. Sometimes I have control of the speed on other occasions it has gone to full speed reverse and I have no control.


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
4th Nov 2017 23:28  
>> Permalink
mdlbt.com/35341

This is sounding more and more like interference and low voltage.
Can you post a few pics of your setup, showing all the wiring, motors, ESCs, Rx and battery.
Are you using Tamiya connectors by any chance? Also are all your connections good - no green verdigris on any?


Live long and prosper

Dave
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
4th Nov 2017 23:55  
>> Permalink
mdlbt.com/35342

Hi John, can you please define 'sometimes' more precisely ?
For example;
At the beginning of a run yes? -> After some minutes running no?
Or right from the start sometimes yes, sometimes not?
Under what circumstances do you have no control?

What is the current setup?
TX and RX make & model?
Motors?
ESCs, still Vipers, TIO version?
BEC or not?
Power source?
Charge status?
Re Dave's comment: can only highly recommend the exclusive use of gold connectors only (regardless of type) between ESC and motor.
And on the battery as well.


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
5th Nov 2017 00:23  
>> Permalink
mdlbt.com/35343

I will take some pictures when I go on Wednesday. The connections are all good. The problem is present either when the boat is first put into the water or shortly within seconds after. The battery is a 3cell Lipo always fully charged before use. I have used a bec and without a bec. Esc's are Mtroniks tio marine 30. I have tried several tx and rx it is currently a Planet!


Happy sailing.

John.
pmdevlin
(Fleet Admiral!)





Forum Posts: 329
5th Nov 2017 17:43  
>> Permalink
mdlbt.com/35371

I've breezed through this so apologies if I missed something. There is no way the boat will magically go into reverse when transporting from the bench to the water. If it works on the bench, it will work in the water, out of interest, how do you know its going the right way on the bench? you might have the props on the wrong way around if directional, so its actually going in reverse on the bench.
You can run multiple motors with one spectrum receiver, I have done it several times, with boats and planes, so its not that. Your later posts suggest more is amiss here, it could be a signal issue, as you say it sometimes works?
Have you done a range test? If you have not, This needs to be the very next job you do. Not knowing specificallky what tx you have, eg the dx6i has a built in range test, and needs to be done from all angles, and should work at least 20 metres from the boat. This needs to be a must on all models. I do this every time I sail or fly, every time, I don't want to lose a model due to signal loss, which depending on the failsafe being set, can result in full throttle and loss of control, that's another topic I suppose!

Mtrokiks are pretty much bullet proof, forget those Chinese blue things, the issue isn't the escs, its the set up.
Get the mixer out, use a "y" lead between the receiver leads, disconnect both red wires, and use a separate receiver 6v feed into the receiver, plug in the esc's, watch the lights to see if they set ok (assuming you have throttle range set them separate first), then range check, nw throttle on the bench, one at a time, with a tissue behind the prop to ensure they are going the correct way, belive me when I say its an easy mistake to make thinking a twin set up has both props with the correct direction when one isn't!😊

I see you are at Bury, thats a big well established club, has anybody there taken a look for you, seeing it in action is so much easier than over a keyboard! If you fancy a trip to the Wirral Ill gladly sort it for you

Paul

John
(Fleet Admiral!)





Forum Posts: 104
5th Nov 2017 18:50  
>> Permalink
mdlbt.com/35378

Hi Paul, yes it sails at Bury and I am continuing to try different options. There has been much head scratching at Bury over the problem and the rescue boat has been out a couple of times to rescue the boat in reverse. The Y leads have been tried as you suggested. It is easy to test the rotation direction by feeling the air flow and slowing them manually to observe them.


Happy sailing.

John.
pmdevlin
(Fleet Admiral!)





Forum Posts: 329
5th Nov 2017 18:53  
>> Permalink
mdlbt.com/35379

sorry to state the obvious, but sometimes the obvious can get overlooked. Have a google and see if the model of mtroniks esc can power two motors, or give them a ring, then you can eliminate one esc, see what happens

John
(Fleet Admiral!)





Forum Posts: 104
5th Nov 2017 18:57  
>> Permalink
mdlbt.com/35380

Hi Paul, yes the easy solution would be to get a single esc to power both the 600 motors. I am going to look into that option if it does not work this week 😁


Happy sailing.

John.
Berty
(Seaman)





Forum Posts: 3
5th Nov 2017 19:22  
>> Permalink
mdlbt.com/35381

Hi John..
Been following this for some time....have you considered that the motors are not going into reverse ! ..but that the prop. wash is pushing against the underside of the hull ....thus giving a reverse thrust similar to that used on a jet engine ....this would only show at increased revs

A rx going into fail safe would not cause this problem neither would not removing a red lead on an esc....I have flown planes with 2....4....and 6 esc,s and never cut a red wire off the esc.

Can't wait to learn the reason in due course

Berty

John
(Fleet Admiral!)





Forum Posts: 104
5th Nov 2017 21:00  
>> Permalink
mdlbt.com/35389

Hi Berty, I am looking forward to the solution myself 😁


Happy sailing.

John.
tomarack
(Commander)





Forum Posts: 23
6th Nov 2017 17:23  
>> Permalink
mdlbt.com/35423

Hi,
maybe you can look at > Modelboatmayhem > Technical stuff >BOAT ELECTRICS & A LITTLE BIT MORE! >
there are interesting recommendations in the article for both engines and ESC.
Maybe it will help you
Tom


Main principle: if It is not broke - do not repair It !
John
(Fleet Admiral!)





Forum Posts: 104
6th Nov 2017 20:39  
>> Permalink
mdlbt.com/35426

Thanks Tom, I shall have a read.


Happy sailing.

John.
John
(Fleet Admiral!)





Forum Posts: 104
7th Nov 2017 18:46  
>> Permalink
mdlbt.com/35454

The pictures with the new ESC's. It will be on the water tomorrow weather permitting.


Attached Files - Click To View Large


Happy sailing.

John.
Dave M
(Fleet Admiral!)





Forum Posts: 1398
7th Nov 2017 20:23  
>> Permalink
mdlbt.com/35458

Hi John
Thanks for the pics.
I see you are using Tamiya connectors. My experience is that they are unreliable and not suitable for currents above about 5amps.
You appear to have the battery wired to both ESCs though one socket. As your problem occurs when both ESCs are connected I suspect the connectors are the culprits as they work then fail fairly quickly. Easily checked by using two separate batteries.
If this is the problem I would hard wire the two ESCs to a chocolate screw block with just one socket for the battery. You might also want to consider a fuse in the positive wire to the battery.
There are two switches, what are they switching and what type of switch?
I can see the Y lead has one red wire taped up so assume power is from one of the ESCs?
Where do you put the rx when the top is on?
Hope you manage to move forward tomorrow.
Dave


Live long and prosper

Dave
pmdevlin
(Fleet Admiral!)





Forum Posts: 329
7th Nov 2017 20:36  
>> Permalink
mdlbt.com/35462

Dave,

mtroinks have switches, so maybe when it had the pair of vipers, they where for the esc's? I would disconnect the red signal wire from the receiver end on the "y" harness, and use a separate 6v receiver supply, I have a number of twin screw setups, with a cheap battery monitor, if the esc fails, you still at least have rudder control, if the feed esc goes down, power is lost to the receiver, ensure you have a failsafe set at zero throttle. With spectrum, its usually automatic, unless...... you have reversed the throttle! that means you throttle will go wide open in event of esc failure. Easy test, on the bench, all set up to go, make sure all the props etc are clear, just turn your transmitter off, see what happens, nothing should!

Have you done the range test? you might have been lucky having it go in reverse,

Also, the gunner that is holding the esc wire, is he wearing a Teflon glove? His hand might get hot

John
(Fleet Admiral!)





Forum Posts: 104
7th Nov 2017 21:03  
>> Permalink
mdlbt.com/35466

Hi Dave and Paul, as the two current esc’s are new under warranty and came fitted with Tamiya connectors. I am reluctant to cut the wires for now hence the connectors. The switches are one from each ESC one of which has the red wire cut. The range test was fine so the tx and rx are fine. The rx goes at the front under the deck far away from everything and above the waterline when it sinks in full reverse. The wires were out so you could see how everything is connected. If this does not work I can try two batteries next.


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
8th Nov 2017 20:15  
>> Permalink
mdlbt.com/35540

Hi John,
PT109? That foredeck and the torpedo mounts look more like a Perkassa to me! No Elco I've ever seen. I'm currently (or shortly I hope) converting an Elco 80 to JFK's PT109.
Anywhere nearer solving your motor conundrum?
Cheers Doug 😎


Attached Files - Click To View Large


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
8th Nov 2017 20:31  
>> Permalink
mdlbt.com/35541

Hi John,
earlier you wrote
"Sometimes I have control of the speed on other occasions it has gone to full speed reverse and I have no control."
Full reverse and non control is the classic case of aircraft Failsafe - Throttle full back!!!! You need to reset your TX to Throttle OFF for failsafe, and then look very closely at where your antenna is mounted. The RX should / may have two antenna wires these must be arranged at 90° to each other and one vertical, one horizontal.
Cheers Doug 😎


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
John
(Fleet Admiral!)





Forum Posts: 104
8th Nov 2017 20:39  
>> Permalink
mdlbt.com/35544

Hi Doug, I am running late tonight due to my list of jobs! The problem is solved! I still do not understand what the problem was but the replacement of the escs has done the trick and she now performs as she should! Sailing today was a real pleasure thanks everyone for your help.


Happy sailing.

John.
RNinMunich
(Fleet Admiral!)





Forum Posts: 1086
8th Nov 2017 20:59  
>> Permalink
mdlbt.com/35545

Very please to hear that Happy sailing 😊
Although as an engineer I always hate unsolved mysteries, gives me a creepy feeling that the real problem hasn't gone away 🤔
All's well that ends well! 👍


"The brain is not intended to store facts. It is for thinking, and for knowing where to find the facts !" Albert Einstein. 😉 cheers Doug
Dave M
(Fleet Admiral!)





Forum Posts: 1398
8th Nov 2017 21:56  
>> Permalink
mdlbt.com/35552

Hi John
Glad to hear you have a working boat. The new wiring and ESCs have clearly removed any previous faults in the connection between the battery and the ESCs.
It was a beautiful calm day at Boundary Park, Cheshire and I sailed my Perkassa so must have been a good day for fast patrol crafts.


Live long and prosper

Dave
John
(Fleet Admiral!)





Forum Posts: 104
8th Nov 2017 22:47  
>> Permalink
mdlbt.com/35555

I was just nice to see her sail Dave. It was very quiet at Bury today, I guess a lot of people thought the lake would be frozen with the early frost we had.


Happy sailing.

John.