Best motor for Tug

[James WingroveParticipant @jameswingrove29221]

I’m about to start myMobile Marine Brackengarth tug build. Hull is 45” and am after advice on what motor to use. I intend using 12v battery and on the MM site they mention a T12 high torque low RPM motor but don’t seem to have the motor. Is there an alternative motor that anyone could recommend. I had considered the mtronics 500 motor but not sure if it would be suitable. Any advice gratefully received

[James WingroveParticipant @jameswingrove29221]

Brackengarth build advice on motor

[ashley needhamParticipant @ashleyneedham69188]

Hello James and welcome to the forum.

Not a tug man myself, but loads out there who are and will pinpoint a suitable motor.

A 500 is NOT suitable, as you will have quite a large prop on there and the 500 will not turn it.

A 2.5:1 MFA geared unit with 500 motor might do, but a large slow non-geared one would be quieter.

Ashley

Edited By ashley needham on 26/03/2023 17:37:29

[Chris EParticipant @chrise]

James

Ashley is right that a 500 is simply not enough motor and won't drive the size of prop that your model needs. A geared 500 will do the job unless you are going in for towing but it will remain marginal.

I use car heater motors for tugs of that size.

[Charles OatesParticipant @charlesoates31738]

As Chris says, car heater motors are excellent high torque motors and have been a popular choice in tugs for half a century or more.

If you prefer a modern alternative, a low kv brushless motor about 500 or 600 kv will be a good but expensive choice. I'm a big brushless motor fan, but in your model I'd still go for a heater motor.

[ashley needhamParticipant @ashleyneedham69188]

Once upon a time you could go to car breakers and rummage around and get out a heater motor but sadly those days are long gone!

An MFA 800 is a lump and will power a largish prop..

The geared motors on 12v are quite powerful. I am sure there are tug specialist companies that advertise motors for such things ??

Ashley

Edited By ashley needham on 27/03/2023 08:24:52

[Chris EParticipant @chrise]

Yes I used to get heater motors from breakers that I wandered around but the last couple came from autojumbles where they wern't the most in demand items. Most are open frame so you can see the condition/wear etc. I have never had one fail.

The 800 motor does look a nice simple & available alternative although on 12v they are rather high revving. 6v or geared would be better from a rpm perspective. For a nice tug I looked for around 2000 – 2500rpm loaded.

I don't know enough about the 800 motor to offer guidance and tugs of this size are too heavy for me these days.

800 motor

Edited By Chris E on 27/03/2023 09:36:14

[ashley needhamParticipant @ashleyneedham69188]

What size prop is being considered?? MFA 800 only 5000 rpm, not an awful lot..

Ashley

[Chris EParticipant @chrise]

I believe it uses a 90mm prop. 5000rpm would be an awful lot for a tug prop of that size & I hate to think what the current draw would be. An ungeared 800 motor on 12v would be so loaded I very much doubt it would be anywhere near 5000rpm.

Edited By Chris E on 27/03/2023 09:55:32

[Charles OatesParticipant @charlesoates31738]

Things must have changed a lot since I was in the UK at breakers yards. I thought you could just go to the counter, explain what you want and the chap or lady found one for you. That's how those places are here, and it was just the same when I was last in a UK yard.

EBay is also a good source of fan / blower motors.

 

Edited By Charles Oates on 27/03/2023 10:27:06

[John W EParticipant @johnwe]

**LINK**

**LINK**

Hi there, days gone by – before brushless motors – the only thing we had, apart from scrapyard motors were obviously the old brush motors. The way to get the most efficiency from them was to either use a gearbox or a belt drive. The rule of thumb was the higher the RPM of a brushed motor the more efficient it was – so – therefore you could gear it down to give it the torque required to drive bigger props. Personally, I myself still prefer to use the 500 and 550 style brushed motors and gear them down with belt drives from MFA or China – for which I have applied the links.

Having re-read some information about the efficiency of electric motors, to refresh the old grey matter – obviously in todays hobby the brushless motor is king. However, it is a lot more complicated to set the brushless motor up – due to the fact of the specialised speed controller required.

Like everything else in life once you get the hang of them, they do become easier to use.

What I have seen though is some folk still gear these brushless motors down using belt drives and gear boxes to obtain a more efficient drive.

Food for thoughts.

John

[Anthony ShilsonParticipant @anthonyshilson68083]

No experience of these motors myself, but I know John Boyd (tugs R us) who is a fantastic tug builder often uses the MFA 800 with a belt gear reduction unit. I think these are available form the component shop. John's tugs have a huge amount of get up and go in them and they swing a relatively large prop too, but I'm not sure they are up to 90mm though.

I'm still old school myself, favouring redundant car heater blower motors for my tugs.

Ant

[Anthony ShilsonParticipant @anthonyshilson68083]

No experience of these motors myself, but I know John Boyd (tugs R us) who is a fantastic tug builder often uses the MFA 800 with a belt gear reduction unit. I think these are available form the component shop. John's tugs have a huge amount of get up and go in them and they swing a relatively large prop too, but I'm not sure they are up to 90mm though.

I'm still old school myself, favouring redundant car heater blower motors for my tugs.

Ant

[Trevor Drabble 1Participant @trevordrabble1]

James , Have you considered the MFA 800 and 850 geared motors from Cornwall Model Boats? ( No connection ).

[James WingroveParticipant @jameswingrove29221]

Thanks for all the replies will avoid the 500 and look at the MFA800, but am a way off needing the motor so have a bit of time to continue research

[Trevor Drabble 1Participant @trevordrabble1]

James , Whilst sorting stuff out I have come across some heater motors as well as a T12 motor . I'll test all when I return at the end of the month and give you first option before offering them for general sale . Hope you find this useful .

Trevor .

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