Prototype build of ELLIE

[ashley needhamParticipant @ashleyneedham69188]

Oh dear Bob tut tut go and sit on the norty step and read your MB magazine from front to back PROPERLY and you will find out !!

Paul (T) is certainly ramming in the articles lately!

Ashley

[Bob Abell 2Participant @bobabell2]

Ahoy there, SlowMo fans!

The Etherow club has been invited to a very high profile Country Show, next month at Lyme Park, Cheshire

So it`s all hands to the pumps to get SlowMo and Brutus ready for the Publick Gaze!

SloMo is finally wired up and nearly ready to go!

Need to spend the available time finishing off, before wrestling with the trickery?

The driver could do with a bit more steering wheel action…..(He turns the wheel in sync with the rudder)

Work in progress picture……The rudder mech and fin is very novel to see in operation

Bob

[shipwrightParticipant @shipwright]

Bob,

What is the name of the show and date at Lyme Park ? I couldn't see any reference to it under "events" on the NT site.

Ian

[Bob Abell 2Participant @bobabell2]

Hello Ian

The Lyme Park Show is on Sunday 15th June 2014

From 10.30 am to 4.00 pm

We shall be sailing on BOTH lakes…….The Cottages lake and the very posh Hall lake, would you believe!

If you visit, will you introduce yourself to us please?…..And that applies to all visitors who know me.

I would like to put a face to the forum members

Bob……..

This location was used to film Pride and Predudice and we have been allowed to actually sail on this lake!

But must steer well clear of Mr Darcy!

We are indeed highly honoured!

[Paul TParticipant @pault84577]

Hi Bob

How much does it cost to get in and if I mention your name will I get in for free?

Re the article I have just read it and seen a mistake……..can you find it

Paul

[Bob Abell 2Participant @bobabell2]

If there`s a mistake…..Is it the name…..Darcy?………I only guessed it was him?

If not…..Then spill the beans!

Car park is probably about £5.00 as it`s Nat Trust

The Hall may be £6.00 per person………Still guessing …….Could be more due to the TV implication?

Mention my name and they`ll probably introduce you to Mr Darcy!

Bob

[shipwrightParticipant @shipwright]

Bob,

Thanks for that prompt reply. Unfortunately I am unable to attend the show (another commitment) but good luck. I know Lyme Park well – it's a lovely location. Hope the weather is sunny for your prestigious boat display on the lake.

Regards.

Ian

[Bob Abell 2Participant @bobabell2]

Question

From the receiver, I have a splitter………

One wire goes to the rudder and fin servo

One wire goes to the steering wheel servo

Is the a way of reversing the polarity of one of the servo's?……..Electrically?

I can do it mechanically, but is not really convenient

There must be!

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Open the servo up, and reverse the wires on the motor? (I'm only guessing, but it's what I'd try…)

[Bob Abell 2Participant @bobabell2]

Hello Amy

I suspect that can be done, but prefer to get some trustworthy advice

Bob

[Dave MilbournParticipant @davemilbourn48782]

Ring Component Shop. They have an in-line servo reversing lead for less than a fiver, although I can't find it on the website. Don't start trying to reverse wires inside a servo unless you know EXACTLY what you're doing; it's not as simple as you might think, especially with surface-mount technology.

Edited By Dave Milbourn on 11/05/2014 23:13:43

[Bob Abell 2Participant @bobabell2]

Thanks very much, Dave

Bob

[Bob Abell 2Participant @bobabell2]

Latest news on SloMo 2

Connected the Brushless motors at last and as expected…….It don`t work!

The fans are running…..That must be a plus?

The man, Ivan, said….."No setting up required, just connect up and switch on"

This is a good advert for Brushless motors?

Needless to say…..I`m thoroughly brassed off!

No doubt, with a bit of rational thinking, it`ll work eventually

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob. I really do not see why you are having so much trouble. Brushless motors are simply that, Their speed controllers are also simply ESC`s. There is nothing else to it.

Could you furnish us with a diagram of how you are connecting everything up plse.

I would try running the boat with just one ESC on one motor first and see whats what,

Here is a question for techy persons. Can a brushless ESC run two brushless motors just like one might with brushed???? or do the three wire connections and their polarity (do they have polarity??) come in to play….

Ashley

(program card, get one)

[Bob Abell 2Participant @bobabell2]

Thank you, Ashley, for your concern

I`m not asking for advice, I`m just moaning

I have now swapped the outer motor wires over and it runs when it feels like it!……And in reverse of course!

What now?……Can`t reverse the wires of course

Wonder if it could be done at the F14 tranny?

Only thinking out loud!

Bob

[Dave MilbournParticipant @davemilbourn48782]

Posted by ashley needham on 29/05/2014 19:05:49:

Here is a question for techy persons. Can a brushless ESC run two brushless motors just like one might with brushed????

Nope. You should regard the speed controller as part of the motor, even if you buy it separately. The rule is one ESC per motor – that's it.

[shipwrightParticipant @shipwright]

Ashley,

Re your question "Can a brushless ESC run two brushless motors …. ?" As Dave Milbourn said the short answer is "no".

The brushless motor and its associated brushless ESC form a feedback loop – the ESC is always sensing the position of the rotor (armature) and making changes to the frequency of the trapezoidal (sine wave like but stepped not smooth) 3 phase magnetic field that is generated by the stator coils. Each motor will require its own 3 phase source (ie each motor will require its own ESC). Sensing the position of the rotor can be done by using sensors or by monitoring the "unused" coils (only 2 of 3 pairs of coils in the stator are used at any moment in time) Have a look at the following graphical presentations on You Tube by Texas Instruments :

**LINK** (part 1)

**LINK** (part 2)

Ian

[Bob Abell 2Participant @bobabell2]

Can I ask an old question for the final time?……Before I cut the wire?

Got two Brushless motors, each with it's ESC and each ESC has a servo wire to a seperate channel in the reciever

The system is BEC……..Are we really sure that one of the reciever wires needs to be cut on a Brushless system?

Think about it before saying it does?

Bob

[ashley needhamParticipant @ashleyneedham69188]

Yes, The BEC is simply a way of supplying power to the receiver. Only need one supply. Dont cut the wire, simply get a scalpel and hold the tag down on the connector and pull the wire out.

DM had a wonderfully simple diagram for this. As it is something you only do now and then I have printed it off to keep handy. Foolproof. FAILING THIS..use a short servo extension lead and cut that wire.

I also keep DM`s "how to connect up batt/motor/esc/rx and servo" diagram in my tool box to answer questions at the pond for those new to the game.

Ashley

[Dave MilbournParticipant @davemilbourn48782]

**LINK**

Click on Fig 16 to enlarge to full size. Full article explaining BEC to appear in August MB. Diagram will also appear with it.

DM

[Bob Abell 2Participant @bobabell2]

Thanks Dave

Already got that, but the little blighter refuses to let go!

Also got the grease too

I realise that it is normal to remove the middle wire, but I was thinking that Brushless may be the exception?

Vintage are not answering the phone this morning

Bob

[Bob Abell 2Participant @bobabell2]

Ha! Ha!……..Had a good idea!

Spoke to Steve Webb models (Robin) and he says that there is no need to remove the wire!

It does no harm leaving it in and it prevents losing power to the second motor in the event of the first motor system failing!

So there it is!

Progress at last

Bob smiling again

[Dave MilbournParticipant @davemilbourn48782]

It does no harm leaving it in and it prevents losing power to the second motor in the event of the first motor system failing!

Feeding two separate power sources into one receiver is just asking for trouble. With a limited knowledge of electronics you need as few potential problems as possible. If I can divine any meaning from the second part of the statement above it seems to be that the failure of one ESC and its voltage regulator will not render the receiver inoperable if you leave both BECs connected. Given enough time I could probably come up with a metaphor which was at least publishable. I can't be bothered.
BEC is the least understood and therefore the most frequently abused part of a radio system. I loath and detest it. Unless you have a firm grasp of electronics my advice is ALWAYS to disable the BEC in ALL of the speed controllers in your model and power the receiver with a separate 4- or 5-cell NiMH pack.
If you or your friend Robin know better then be my guest. I shall keep my counsel on the matter from now on.

Dave M

[Colin BishopModerator @colinbishop34627]

Bob, I would be rather inclined to follow Dave's advice. he is a specialist in electronics with yonks of years experience and a first class reputation for building, selling and explaining model boats electronics gear. All the stuff I have bought from him in the past has worked first time and every time but you do need to read the instructions which are clearly set out.

Having two ESC BEC circuits supplying the receiver is certain to have the potential for introducing glitches. To put it in more commonly understood engineering terms, if you have a tap (receiver) which is jointly connected to two water tanks each of which is also supplying a high pressure hose and the two hoses are being turned on and off at different rates and times – would you expect the water coming out of the tap (voltage) to be constant? Electronic devices prefer stable power supplies, otherwise they are prone to glitch, especially at the very low voltages used in our models.

The problem even manifests itself in large cruise ships using diesel electric drive where an imbalance between the supply and the load can, and has, shut down the whole installation, sometimes temporarily and sometimes accompanied with lots of explosions and sparks!

Like Dave, I also prefer to have a separate stable supply to the receiver which will not be affected by anything that might be going on in the motor/ESC setup. With the capacity of modern batteries only the tiniest of models cannot carry sufficient capacity to power the receiver for the length of any reasonable sailing session.

Colin

[Bob Abell 2Participant @bobabell2]

Thank you Dave and Colin for your good advice

Steve Webb of Frodsham are Brushless motor experts and so is Dave Milbourn…………I`m "Piggy in the Middle"

I `ve tried DM`s instructions on Brutus and the result was……. Only one motor will run

So I`ve connected both servo wires to the receiver as recco`d by Robin of Steve Webb Ltd and both motors ran nicely…..Believe it or not!

But one motor was rotating in the wrong direction

Swapping the motor wires over achieved no improvement

Since then, only one motor will run……..Just like Brutus…..But will run in fits and starts!

Finally…….I have reached the end of my tether now and will be scrapping the lot with the greatest of pleasure!

Will also be fitting normal motors shortly, when I come down to earth……….I`m somewhere between Jupiter and Saturn at the moment!

I can only think Two Brushless motors can`t get on together?

Bob

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