Thank's again Red.

Martin555.

As I said originally Martin - if its a 5 pole no problem for your ESC - try a 10amp fuse first - they make a 15amp as well but that could be problematic with pushing the limit of the ESC.

Looking at the specs again 10amp should be fine as the load on 7.2v should not exceed that..........

Unfortunately Howes still list the 540 5 pole you have under the same name as the 540 3 pole - however as said before they have no stock but do list a 545 of a different brand...........

Thank you Red,
I am going to give it a go.
Thanks again.

Martin555.

As I said originally Martin - if its a 5 pole no problem for your ESC - try a 10amp fuse first - they make a 15amp as well but that could be problematic with pushing the limit of the ESC.

Looking at the specs 10amp should be fine as the load on 7.2v should not exceed that..........

That's better Doug, it's definitely a 5 pole Martin.
Cheers Colin.

Different converter 🤞
😎
Better 😀
Sure looks like 5 to me Martin, alone from the size of the segments.
Whatever, your ESC should be fine with a 10A fuzzy 😉

Thank's Doug that is a much better video.

I agree 5 poles (white mark to white mark)

I used an iPad to take the video.
Martin555.

Hi Guys,
Sorry the plan of this thread was to see what boat/motor/ESC/prop/battery combinations you guys have but i ended up hogging it.

Martin555.

Hi Martin,
Sure looks like 5 to me!
Wonder why it has the wrong label, or MFA cocked up the website?🤔
Just tried a conversion of the MOV vid you sent me.
Let's give it a whirl 🤞😉
Cheers, Doug 😎
Odd🤔? That came out grainy as well, although the original was much better!
And the converted mp4 file plays perfectly with Windows Media Player.
Did you take the vid with some kind of phone or tablet?
If so which? Might help with the conversion to know that.

Martin, I only counted 3 segments, but the wires look fine enough for a 5 segment motor.
Gone to look in my motor box, back soon.
Cheers Colin.

Hi Doug,
I think i managed to convert this video on the MFA 540 motor.

I started were the white mark is and ended at the same place.

Hope the video works, if not i will delete it.

EDIT
It is a bit grainy but i think you can see the poles.

Martin555.

Thanks Doug,
I don't have any brackets with this motor,
I did what you said with the tape and still count 5.

I got the wife to do the same and she counted 5.
And that was the most interest she has ever shown in my boat building LOL!!!
Looking through the casing slot it looks like photo 1

I have just sent you a short video in an email.

Martin555.

Hi Martin,
Colin is correct 👍 your motor, Part No.457RE-540/1, is deffo a 3 Pole job.
(Unless someone goofed and put the wrong label on it 🤔)
https://www.mfacomodrills.com/pdfs/RE540-1.pdf
You should still have the mounting bracket kicking about somewhere 😉
At 7.2V it shouldn't draw more than a handful of amps with the 35mil prop.
Stall current probably around 9A so you'll be fine with the 10A fuse.
I have two similar 540s (from Graupner back then) driving my 135cm destroyer, each with a 35mm prop. Goes very well all day drawing about 5A/motor flat out, which is QUICK 😀
Power supply is (was!) 12V 7Ah SLA, switchable to 6V for patrol cruising.

The 5 Pole version is Part No.457RE-540LN (WITH BRACKET).
https://www.mfacomodrills.com/pdfs/RE540LN.pdf
As you can see from the specs the 5 pole delivers more torque but less power than the 3er.

Easier way to count poles is,
Wrap a chunk of masking tape around the shaft as an indicator flag.
Note where it is, e.g. straight up, and slowly rotate the shaft feeling for the 'clicks', as the rotor 'jumps' from pole to pole, until the flag is back in the same place. One click per pole 😁
Woiks for me 😉
Cheers, Doug 😎
Here the MFA motor list with links to each spec.
https://www.mfacomodrills.com/motors/motors.html

Thank you Colin.
I get confused quite easily just lately.

I can build but no good with the technical stuff.

As You probably already know i try things and when they go BANG then i know not to do that again LOL!!!

Martin555.

Martin, you clever fellow, it must have been an early one as most 540's are3 pole, But when they changed to 5 pole they usually called them 545's. To denote the 5 pole version, but sometimes they were still marked 540.
Sorry for the confusion shipmate, but that's the better version and your prop choice is whatever you find works best.
Cheers Colin.

Hi Red,Colin.

I am loosing the plot now.

This MFA 540 Motor is 5 pole i think.
I managed to mark one of the windings on the armature through a slot with a white pencil so counting that at No 1 i rotated it very slowly and you could feel like it had slight resistance and then it was on the next winding.
I felt 5 windings starting with the white one and ending on one before the white one.
If that makes sense.

So 5 pole.
Please correct me if i am wrong.

I am limited to props, i have :-
2 blade 35mm
3 blade 49mm
3 blade 55mm

The Johnson 600 motor has a built in fan so that is now out of the equation.

I am now thinking about going with The MFA 540 and a 2 blade 35mm prop and the Mtronik Marine 15 and 6V -7.2V battery. ??????

Martin555.

Martin the pictured 540 you have is a 3 pole and I would use a 10 amp fuse, that would be the same setup as in my 34" crash tender using a viper marine 15 amp esc. Just checked and my prop is 35mm 3 blade brass.
Cheers Colin.

Thanks red,
I am going to have to think about this for a while.

Martin555.

Martin if you have a MFA 5pole 540 it will be ideal using your 49mm prop cut down to say 40mm or buy a new 40mm plastic (nylon) which will do fine.
I have cut down various props successfully on my original Unimat - but a drill will do . Clamp it down somewhere put the prop on a short shaft in the chuck and mark the bit to cut off on each blade using say a pencil taped to block at the correct height (DONT switch the drill on its simply used to check the blades). Then you must check again after the cut ensuring the blades are all the same to keep it balanced.

I use a rule of thumb for props - never exceed the casing diameter unless its a 5 or more pole motor when you can increase that slightly because of the higher torque/lower revs

Hi Red,
I have a 49mm 3 Blade but no way of gearing down the motor.

Martin555.

Martin if you gear the MFA 540 down slightly and use a larger prop - say a 40mm 3 blade it should be fine and give you a decent running time.

If your Johnson 600 has a built in fan beware - just looked it up on line ( mine is not the fan version ). The one with built in fan can exceed 80amps under load - not good for your esc . So check it carefully and suggest you test it before you use it in the boat. Don't know why they have different versions under the one name.

Looked up MFA 540s on Howes Models site - there are two versions - the one has 5 poles and would be ideal - the other 3 pole has 14.98amp at max efficiency - too much for your ESC. Bad news is they are out of stock of the 5 pole. Assuming yours is on hand check the number of poles it had by looking inside the slots or by feel when you turn the motor (which is harder to do)

Thank you Colin.

Now i don't know what to do!

We don't want this boat zooming of like a rocket.

I think i will have to toss a coin to decide LOL!!

Martin555.

Martin, spot on, that's the same motor I use in my Vintage Tamiya Hornet racing buggy which I have used since 1984 for rough terrain hill climb racing, only on my 3rd motor in all that time, I use 3000mah 7.2volt nimh battery pack which give between 40 and 60 minutes racing.
Also in my original aerokits fire tender using a 30mm 3 blade brass prop, and 3000mah 7.2 battery pack. Which lasts for 30 to 60 mins run times depending on if using monitors and lights.
Cheers Colin.

Hi Red,
Thanks again for the information.

I think i will stick to the original plan using the Johnson 600 motor.

I will experiment later with the motors i have, but for now i will just carry on building.

Martin555.

Hi Martin - suspect that it might be an amp eater - the usual type for low draw is a 545 . Which only indicates its 5 poles. The voltage range on this 540 however might mean that at 7.2v its not too bad - however its usual for an amp eater to draw more current at a lower voltage. Can you have a look inside ? - not clear from the pic if there are any side slots. You could also try my previous suggestion but using the esc - put a fuse in line to enure the esc's safety. Cheap enough to use car fuses - local shop keeps them with wiring attached - one of the few cheap things in there.......

Looked on line - the stall current (which is the theoretical max) at 6v is 9.31 amps and 13.85 amps at 12v . Should be safe with that motor at 7.2v , Suggest you still test it using a safety fused esc.........

Goodnight Grandma

I have just found another motor, It Is a MFA como drills 4.5-15Volt. D.C. pt.No. 457-RE 540/1 (Brushed)

I had a quick look on line
At the spec's but it don't mean much to me.
So i was wondering if this would be better than the Johnson 600 (Brushed) setup that i previously mentioned.

Colin,
Is this the 540 Brushed motor you mentioned ?

Martin555.

Thank's for the information Red,I will have to have a play later.

Martin555.

Hi Rick,

Rightly or wrongly my model making style it try it if it goes bang then you don't do it again.

I can make models but i don't do all the maths working out of the technical stuff.
I suppose i could do if i had to.
So in answer to your question.
I don't know!

Martin555.

Have a look at the windings through the openings in the casings and check the number of poles and size of wire - thick heavy wire is amp eater = 3 pole fast = 5 pole slow with lots of torque and finally light wire lower current draw obviously same goes for the poles. Give you some idea at least . Test them out in your test tank connecting direct from the battery - that should give you some idea of what they are. If you have a couple of props you could use a plank drilled through for the shaft as your test platform - restrain with a piece of heavy cord. Unfortunately though a plastic plank wont float.......... will have to use wood !

However all is not lost - a second thought is you may be able to make a type of bottle boat to use instead............. sailing types use a 2L cool drink bottle heated & squashed. All that from your favourite material

Having said that Grandma will go back to sleep............

Hi Martin,
If its a Johnson 600 its a good motor to use . Have one - has lots of torque and not a real battery eater. Be a good set up with what you have got. Unless you want a speed boat you could try a 3 blader plastic - not too expensive . Chose one with not too finer pitch to make use of the torque.

Martin is there a way to put the other two motors under load to see if they may work better than the 600 motor.
Rick

Hi Colin,
Thank you for your reply.
I do have two other motors but unfortunately there are no markings at all on them so i don't know what they are.

So it looks like i am stuck with the 600 motor due to budget.

I will try and convince my friend to up the budget but don't hold up much hope as he still has to get his RC equipment and is already moaning about the cost.

Martin555.

Martin, now I see your setup I still think you would be better with a 540 brushed motor or a bigger esc, either way don't forget to fuse the motor at a maximum rating of 15amp with your current setup.
Cheers Colin.

Sorry Guys,
I should know better.
I will start again.

I plan on using the following :-

Johnson 600 (54370 333811) (Brushed) Motor. (36-38mm can size)
Mtronics marine 15 (Brushed) ESC.
Two bladed 35mm propeller.
3000 7.2V NiMH Battery pack.

Doug,
RE :- Why did you post this as a new thread start instead of just a New Update to your MOJO Build Blog?

I was hoping that this thread would lead to some Boat/Motor/ECS/Batterie combinations so other members would find what they are looking for too.

Martin555.

BTW Martin,
Why did you post this as a new thread start instead of just a New Update to your MOJO Build Blog?
Cheers, Doug 😎

Totally agree Doug, wasn't quite sure if Martin was going to use a brushless motor, but I think his best bet would be to use the setup we have both mentioned, easy to work with, and less problems👍

Cheers, Pete

"Perfect mix Martin, 600 BRUSHED motor, 15 esc and a 35mm prop"
Agreed Pete, IF it's a brushed motor!
But Martin says he has a brushless.
Then he needs the Hydra version of the Mtroniks Marine 15.
And he might end up operating on the ESCs limt.
Cheers, Doug 😎

Perfect mix Martin, 600 BRUSHED motor, 15 esc and a 35mm prop, virtually the same setup for a club 500 boat, but you will find that this setup is fine for your kit.😊

Cheers, Pete

btw, a 7.2 volt battery will give you enough time before you are bored😁

"My query is will the ESC be OK for this Motor and battery combination."
Hi Martin,
IF your '600 Johnson' is a 'standard' version it is brushed, with a 36mm diameter body.
https://gimsonrobotics.co.uk/categories/dc-electric-motors/products/speed-600-johnson-3v-12v-dc-motor
In which case your 35mm prop is ideal.

As you and I have so often responded to such queries-
Give us the model/type numbers of the components.
Or at least a photo of them together showing the type numbers or any other markings.
There are at least a dozen 'type 600 Johnson motors',
https://www.johnsonelectric.com/en/product-technology/motion/dc-motors/industry-compact-dc-motors
and only two of them are brushless of a similar can size to the standard brushed motor, i.e. around 36mm.
https://www.johnsonelectric.com/en/product-technology/motion/ec-motors-brushless/industry-ec-motors?series=Low%20Voltage%20EC%20Motors

There are six types of Mtroniks Marine ESCs and only two are brushless
See attached link.
https://www.mtroniks.net/cat/Boat-Speed-Controls#category_id-583/applied_filters-f14/order-PLH/page_number-1/items_per_page-240
So which combination do we have here?
Don't want you to connect up two wires from of the motor / ESC and end up wondering where to stick the third wire! 😮
As far as I can figure out the current draw of a 'typical 600' on 7.2 - 12V at max efficiency is around 15A. So whichever you have the Mtroniks XXX 15 ESC will be operating on it's absolute limit. Also bear in mind that the stall current of the 600s can be anywhere between 40 and 80 Amps! 😮🔥😭
Cheers, Doug 😎

Martin, that sounds okay to me. As I'm new to brushless I would ask one of our more knowledgeable members.
Cheers Colin.

Thanks colin,
I forgot to mention the prop i will be using is a two blade 35mm.
And the 600 motor is brushless.

I had been advised to use a 500 brushless motor with the combination i have mentioned.

Martin555.

Good question Martin it would all depend on the size of propeller you use. With the motor model, I would use 540 motor if possible or a 9.6 volt battery pack. Otherwise you should be fine.
Cheers Colin.