Mabuchi 555 motor

[David Marks 2Participant @davidmarks2]

[David Marks 2Participant @davidmarks2]

I have installed a Mabuchi 555 motor in my latest boat, running on 12V and via a Mtronics ESC. Can anyone tell me why it runs a lot faster is reverse than it does in forward mode. I do not consider it detrimental to the model but would love to know the reason, purely out of curiosity.

[Dave MilbournParticipant @davemilbourn48782]

David

It could be the speed controller or your transmitter or the 'timing' of the motor. I would suggest changing the position of the servo reverse switch for that channel and swapping over the two leads from the ESC to the motor. The motor will then run in the same direction as before but it will be faster forward than in reverse.

Try it and see

Dave M

[David Marks 2Participant @davidmarks2]

Dave – I will give that a try tomorrow and give you an update on the outcome.

Regards – David M

[David Marks 2Participant @davidmarks2]

Dave – Mission accomplished. Now runs fast in forward and at about 50% of the forward speed when in reverse. As I am not into `docking' and the like, the reverse gets little use, apart from emergency use.

David Marks

[Dave MilbournParticipant @davemilbourn48782]

Jolly good; still curious, though.

Dave M

[ashley needhamParticipant @ashleyneedham69188]

David. Did you do a setup on the ESC? you know.turn tx on, power esc on, press button on esc and then put throttle stick full ahead then full reverse?? this clears that sort of issue sometimes.

Ashley

[Malcolm FraryParticipant @malcolmfrary95515]

Futaba like to be different while still appearing to be within general standards. For years past, while everybody else used 1.5mS as the standard for "off" or stick center, Futaba preferred to use 1.25mS. Again, for everybody else, a longer pulse meant forward, a shorter one reverse. Futaba, the opposite.

For anybody not having Futaba gear, not a problem until you get an ESC designed by somebody working to the Futaba standard. As Ashley says, quite often you need to "train" an ESC to "learn" your transmitter. It expects to "see" three things. First is the neutral, then forward, then reverse. If it gets them in the wrong order, what happens is anybody's guess, but if it doesn't respond as expected, the best thing to do is start over, but set the throttle channel reverse switch on the TX to the opposite of what it was the first time.

[David Marks 2Participant @davidmarks2]

Gentlemen – I will try resetting the ESC again over the weekend. I did have some rouble with the SC at the pond last weekend which resulted in a replacement item being fitted. Currently wiring the various lights.

[Bob Abell 2Participant @bobabell2]

David

I have a similar problem

Using Four MFA 850 motors on 7,2 volts…….One motor only…….Gets hot very quickly and also runs lovely going in reverse but not going forward

I like Malcom's story, but it doesn't quite fit my set up?

ie……Three motors ok and one rogue motor?

Bob

[Bob Abell 2Participant @bobabell2]

Pleased to report that the motor is now running with complete satisfaction

I just reset the ESC…….As Ashley recommended……….Obvious really, but thanks matey

Dare I ask the old Chestnut question?………Hope you don't mind David

I have four motors and four ESC's…………None of the red wires have been cut

The system runs nicely and yet, the experts say that only ONE red wire should be connected to the Rc

Why do they say this?

Bob

[Dave MilbournParticipant @davemilbourn48782]

Why do they say this?

I give up, Bob – what's the answer? In the light of your experience it's clearly nonsense so why would MTroniks – who manufactured your four speed controllers – include it in their instructions? I think it's time you told us experts where we're all going wrong, Bob.

[Bob Abell 2Participant @bobabell2]

So you don't know then! Dave?

Any body?

Bob

[Dave MilbournParticipant @davemilbourn48782]

I do know, and I've given the answer more than once on this forum and in my articles.

I offer my advice freely in the hope that it will help others to avoid trouble; it's not for some monstrous ego trip or the thrill of seeing my name on a computer screen. You seem "unabell" to appreciate this. I'm not about to repeat myself yet again simply for your amusement, except to say that just because you've avoided problems while ignoring advice thus far doesn't make them any less likely to happen in the future.

Part of me hopes they do, but I won't be the one to say 'I told you'.

[Bob Abell 2Participant @bobabell2]

Has anybody out there experienced problems with their motor drives, by not cutting the wire, please?

Bob

[Paul TParticipant @pault84577]

Bob

Are all of your red wires connected to the RC

Paul

[Dave MilbournParticipant @davemilbourn48782]

"CAUTION!" (Red text) – Third line et seq.

[Bob Abell 2Participant @bobabell2]

Paul

Yes……All the wires are connected

If I cut the wires to three of them, I would not be able to run an individual motor, without first connecting the intact wire

At the moment, I can run any of the motors…….Which has been handy lately

Bob

[Paul TParticipant @pault84577]

Bob

Your wiring is obviously working and yet it contradicts the manufactures recommendations so you will appreciate the concern especially if someone else follows your example and destroys their expensive electronic equipment.

To put everyone's mind at rest could you explain how you wired up your motors and perhaps you could include a wiring diagram.

Paul

[Colin BishopModerator @colinbishop34627]

Bob,

As Dave says, this has been explained on numerous occasions. Each red wire is a separate power supply from the speed controller to the receiver. In an ideal world, when using more than one speed controller the outputs will all be identical but because of various factors including manufacturing tolerances the separate loads being placed on the speed controllers by the motors etc., in practice the supply voltage can fluctuate and because everything is interconnected there're is a very real potential for the electronics to become unbalanced and generate unwanted feedback as a result of which one of the components may get fried. It obviously makes sense to power the receiver from one power source, either a separate battery (my preference) or one speed controller.

In a sense you are already experiencing a not dissimilar problem with your twin motor one shaft setups. The two motors should perform identically but in practice they don't because they have differing manufacturing tolerances and the pole positions are probably out of synch so they don't act exactly in unison when power is applied. They are fighting each other.

Your setup may indeed appear to be working OK but what you can't see is the internal stresses it may be putting on the electronics. When the device self destructs the manufacturer gets blamed which is why they use red ink in the instructions as Dave has illustrated above.

Colin

[Bob Abell 2Participant @bobabell2]

Many thanks, Dave…….I only wanted to know the reason, so that I could decide whether to cut the wires or not

Having Googled the question…….There were so many people asking the same question and the replies did not highlight a hazard

The club expert, says, cutting the wires is good practice and agree`s that I seem to have got away with it!

Sorry David Marks 1……We seem to have messed up your thread

Shall we vacate?

Bob

[Colin BishopModerator @colinbishop34627]

PS: If you want to run the motors selectively then just use a separate receiver supply, you only need 4 AA cells for that. Then you can switch the motors in an out to your heart's content.

Colin

[Bob Abell 2Participant @bobabell2]

Many thanks Colin……..For your posts

I`ll give all the posts much thought and make a decision shortly

I`m hoping something will come out of this, when the time arrives…….Some manufacturer will give the matter some serious thought and declare that the difference between similar ESC`s is so minute……..There is no problem after all!

It`s possible

Bob

[Colin BishopModerator @colinbishop34627]

Well, it may be possible Bob, but 100,000+ ton cruise ships not infrequently suffer total electrical blackouts due to their 'speed controllers' getting their electronic unmentionables in a twist when trying to balance the loadings on them so what hope is there for a £25 model controller made up of a few cheap Chinese components?

Colin

[Dave MilbournParticipant @davemilbourn48782]

Bob

You have spent a year and a lot of money building a large and impressive model boat, yet you have chosen to ignore the advice of several folk on this forum and also gone against the instructions of the ESC manufacturer. This could (but not necessarily will) have consequences.

The first one of these is that it invalidates the warranty. Whether or not that bothers you is your concern only

Secondly, MTroniks ESCs are known for catching fire for no obvious reason. I have had several customers who have experienced this. It's lucky in your case that the input voltage is only 7.2v, so the power dissipated by the regulators in the ESCs is pretty small. However pitting the output voltage from one regulator against another – and then multiplying the risk by two – does nothing to reduce the chances of a serious fire.

This isn't my model and frankly I really couldn't care much about its fate, but I feel that I would be called to account if I hadn't said or done my best to dissuade you from such recklessness. It would take the work of maybe a couple of minutes to disable all but one of the ESCs, in line with MTroniks' instructions. I'm not sure what point you're trying to prove but it won't be on my conscience.

Do what you like, Bob; it's your style – for better or worse.

Dave M

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