Brushless Motor

[Peter Brown 15Participant @peterbrown15]

I’ve just fitted a replacement 2435 4800kv 12t inrunner in my aero-naut Classic sports boat. It’s certainly shifts. I have the same motor I want to fit in my small Samson tug. I obviously don’t need the speed requirements. A suggestion was to fit a lower voltage battery such as 4.8v so the rpm is less. What do you think?

Edited By Peter Brown 15 on 06/08/2018 07:21:50

Edited By Peter Brown 15 on 06/08/2018 07:22:25

[Peter Brown 15Participant @peterbrown15]

Samson Tug

[Trevor Drabble 1Participant @trevordrabble1]

Peter , I would suggest that you look at the huge range of gearbox options available from MFA/Comodrills . Trevor.

[harry smith 1Participant @harrysmith1]

Hi Peter

The MFA/Comodrills 919D61 has a 6:1 gearbox and the 919D111 has a 11:1 gearbox both with a RE540 brush motor.

Harry Smith

[Dave MilbournParticipant @davemilbourn48782]

Peter

Even with 4.8v you're talking about 23,000RPM. The right brushless motor would be an outrunner [for the torque needed in a tug]; nearer 480kv, and would probably cost less than a gearbox for the one you have.
For a small tug like the Artesania Samson I'd be thinking along the lines of a small brushed motor like a 385 – or a 555 at most. Using your 4800kv inrunner would be like putting a Formula 1 engine into a quarry dumper truck.

Dave M

[Charles OatesParticipant @charlesoates31738]

Hi peter, you need to get prop revolutions of about 10 rpm to around 2000 at the most. Tugs = low revs, largeish prop and high torque. If it were mine I would just use a geared 385 such as the one from MFA/Como. Try it on 7.2 volts, it will run for a long time on most batteries.

I love brush less motors, but only in the appropriate model.

Chas

[Peter Brown 15Participant @peterbrown15]

Dave

That makes sense. The only problem I have is fitting it into the Artesania Samson. I don't particulary want to mess about with the mounting , can I use the existing mounting that was supplied with the kit? The inrunner I have fits perfectly into the mounting holes which is the same as the 380 motor I had previously. Se photo

[Dave MilbournParticipant @davemilbourn48782]

Peter

If you follow this link and click on Video you'll see that it's a 385 which is fitted into the manufacturer's own model, using the mount supplied. **LINK**

It is connected directly to the prop shaft i.e. no gears, and looks to be run on a 6-cell buggy pack of NiMH cells. A 385 will cost you less than a fiver and a small BEC-equipped ESC about £19 – less if you go the Chinese route.

Dave M

Edited By Dave Milbourn on 06/08/2018 10:46:34

[Dave MilbournParticipant @davemilbourn48782]

BTW the mounting holes for the 385 are identical to a 380.
DM

[Peter Brown 15Participant @peterbrown15]

Thanks all, I’ve replaced the 380 motor back into the tug.

[Peter Brown 15Participant @peterbrown15]

Just wondering now I've switched back to the brushed 380 if I could get a small outrunner that would fit my existing 380 mount like the 2435 inrunner did. 

Edited By Peter Brown 15 on 09/08/2018 21:34:05

[Dave MilbournParticipant @davemilbourn48782]

The Turnigy 28mm outrunners which I favour have two of their four mounting holes at the same spacing as a glass-nylon 380/400 mount.

Dave M

[Charles OatesParticipant @charlesoates31738]

Hi Peter, to get meaningful answers, can you clarify why you want to change the motor. Isn't it performing as you want it to? It would also help if you can clarify if you have a 380 or as Dave says, a 385, they are very different motors and I would be surprised to see a 380 fitted. It's worth remembering that a tug needs torque more than revs to perform well.

Chas

[Malcolm FraryParticipant @malcolmfrary95515]

Posted by Charles Oates on 09/08/2018 23:40:18:

Hi Peter, to get meaningful answers, can you clarify why you want to change the motor. Isn't it performing as you want it to? It would also help if you can clarify if you have a 380 or as Dave says, a 385, they are very different motors and I would be surprised to see a 380 fitted. It's worth remembering that a tug needs torque more than revs to perform well.

Chas

………..and putting a 380 where a 385 belongs is a recipe for a cooked motor.

A couple of years ago a pair of lads wondered why their runabout had stopped. When we had recovered it, it became apparent that the highwayman who had prepared it for them had fitted a really high revving 380 size race motor to a large prop. It got hot enough to melt the solder connections. We couldn't figure the type since the label had burnt away, but the windings looked REALLY thick.

Fast 20" launch, 380 on its rated voltage and a small prop. Small tug with a large prop, 385 on about half the rated volts.

[Peter Brown 15Participant @peterbrown15]

Thanks Dave the photo helps. Yes it is a 385 motor. No particular reason why I want to change to brushless just exploring different options. My 385 performs well and the motor doesn't overheat. I usually run my tug on a lake for about an hour twice a week. I do give it a few breaks in between running while I have a chat with my mates. I may need to change my prop looks a bit on the large size.

[Charles OatesParticipant @charlesoates31738]

Re your prop size, I'll refer you to Malcolm s comments. You might experiment with a 3 blade if you want to test options. It's always worth remembering that old saying, if it ain't broke, don't fix it, but I have to admit that trying things out is fun and a great way to learn.

Chas

[Peter Brown 15Participant @peterbrown15]

Checked my Tug, it turned out I had a 380 motor. I've now fitted a 385 motor and a new brass propeller. Should have more control at lower speeds.

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