Brushless Motors

Started by redoctober
15 replies 3 likes 0 followers Last activity: 16 years ago
#16
Hi Marky, arrived today YAY!
only had chance for a quick peek as grandson was here and I am in constant demand if the had seen it would. Have wanted to get stuck in he is just gone 8 y/old and is going to be boat crazy he is also into this ipadd and has no concentration I just hope I am around long enough to get him started.
Well many thanks for sorting this for me will sort out with you soon as.
All the best
Mick.
Michael beck Wilkins McQuilkan
#15

Brushless Motors

If it's over proped at high revs it's also overproped at lower revs so will get hot the same.

HS93
Liked by ralphwilmot
#14

Brushless Motors

slightly off topic, but I was interested in Dave M's comments regarding overheating motor at slower revs, I was using my Huntsman last night, it runs on an align 1650kv brushless motor, 120amp castle creations esc, 6 lipos cells. Usually, its flat out 😀 but last night on a small lake I was going 1/2 throttle, after 15 mins the motor was as hot as when its flat out, any reason for this? I was expecting it to be cool due to low revs?
Thanks
#13

Brushless Motors

The whole point of using Hall Effect sensor is to control low-speed scale speeds.This is why they are used for rock crawlers.They operate from zero speed on without stumbling or cogging.ALSO brushless inrunner motors stay cool while running because the windings are next to the motor housing.I'm using a 6.6 volt LiFePo battery pack and get hours of usage.To generalise brushless motors in one group is like saying that all motor designs are the same.A low kv outrunner motor will work perfectly with a correct non Halls Effect ecs ( Castle Creations) , providing the kv and torque rating matches the prop size.This is the most Important match that is seldom considered when using brushless motors.I like inrunners for their durability,cool running,powerful torque,direct drive capability and energy efficiency.
Some of the newer generation brushless motors/esc combos have pc connectivity for precisicely programming the low/high speed adjustments,instant braking and reverse adjustments.
I'm using an 8.5KW brushless motor used in full-scale boat propulsion drives.It uses a Halls Effect sensor esc and it has excellent low speed control.I use this motor on my custom built drill press that requires precise control for a combination drill/tap bit.
There are many rc boat builders using brushless motors for low-speed scale use all over the world and will eventually become the norm,especially when the prices are dropping substantually as we speak.I have no investment in these BL motors other than my own use.
Regards,
John
Regards,
John
Regards,
Giovanni
#12

Brushless Motors

HI Andy H
Looked at this motor. Turns a big airprop at several thousand revs and uses 38amps.
I am a fan of brushless motors but have not found any that would be suitable for a scale model where tork at low revs is Important. My scale models have average prop speeds of a few hundred revs/min and consume 1 or 2 amps. I can sail for several hours on one charge and the models sail at scale speed.
My fast fire tender with brushless motor is very exciting for about 20mins and is turning the prop at approx 15-20000 revs and drawing 15-20amps. I can reduce the revs by using a computerised transmitter and reducing the EPA etc but the motor then overheats, I have also tried a lower battery voltage with similar results.
Sorry but I remain unconvinced that Brushless motors are the best for low revving model boats. I accept that the technology is available but it will cost as Hall sensors will be required together with additional control circuits.
Thanks for your suggestion but I think I will stay with brushed motors for my non fast boats.
Dave
Live long and prosper

Dave
#11

Brushless Motors

Hello,
I am just a newbie here but have been into rc for lifetime.
I am building a 1/12th scale all-metal #260 brass USS Holland submarine with an in-runner brush-less motor used for rock-crawler vehicles.These BL motors are very slow running and controllable with Hall sensors and proper esc.They run very silent,cool and efficient.Depending on the size of your model you may or may not need a prop drive reduction system.I'm running mine direct.The motor has a number of windings that make 1600kv (RPMs per volt).This is much lower than outrunner motors.The motor can be very low slow scale running because of the Hall sensors signalling back to the esc where the motor rotor is positioned.I am using 2-A123 battery cells with a total of 6.6volts.This pack will run everything and if you want more volts in the main battery pack , the esc has a bec built in but I doubt that it is needed.I'm using a Novak Ballistic motor and a Crawler esc.Some of the latest and greatest A123 chemistry batteries are made by Hyperion G3 Life packs and Life Source batteries.
Regards,
John
Regards,
Giovanni
#10

Brushless Motors

I have got a Huntsman28 (42") running on a brushless/lipo set up. it was well documented on mayhem forum, the full build is there. Going to the original posted question, a brushless set up in a tug, I doubt (in my opinion) its worth the bother, as you dont need speed, which brushless will deliver. Unless you get a very good quality (and expensive!) esc you might struggle getting a smooth slow speed, and a quality motor, the cheap ebay stuff that I have in other boat projects gives jerky performance, almost none proportional feel when driving. Fireboat on this site has a brushless setup ( I think!) in his fireboat that performs very well
#9

Brushless Motors

Hi, Dave, Andy.

Sorry I have not been up to date with your posts I have just returned from a weeks holiday to-day ( Friday 21st )
and just started to catch up on events, I note with interest the comments
raised by Andy on the brushless motors, which are apparently available
on a slower speed, and look to seeking more information on these .

Ray
#8

Brushless Motors

I'll try Dave

What's the size/displacement of the boat and what esc is fitted now?

I wouldn't be able to give you an accurate replacement but I could probably steer you in the direction of something to start experimenting with, take a look at these to start off with

[url=http://www.giantcod.co.uk/xyh4260-500kv-outrunner-p-404601.html]brushless motors[/url]

[url=http://www.giantcod.co.uk/hobbywing-seaking-reverse-program-brushless-p-403647.html]ESC[/url]

[url=http://www.giantcod.co.uk/programming-card-p-402375.html]programming card[/url]

I've used gear from this supplier and it was very good
Liked by ralphwilmot
#7

Brushless Motors

HI Andy
Please will you advise which brushless motor on sale via Giant Cod would be suitable for a scale model boat with a scale speed of 10 knots max.
Thanks
Dave
Live long and prosper

Dave
#6

Brushless Motors

It used to be the case that "going brushless" was only for high speed models but there are now slow revving brushless motors which are entirely suitable for scale boats.

A big bonus is their efficiency, running times are increased. Also they are smaller and lighter, not Important for big tugs but it's useful if you're building a small model.

There is no rule of thumb when replacing brushed motors due to the fact that brushless boats are relatively new (we've pinched them from RC planes and helicopters for which they were designed), also the (mainly Far-Eastern) manufacturers have such a variety of styles and ratings, this makes it a case of trial and error unless you know someone who's done all the experimental work already.

I like the fact that parameters can be programmed into the speed controllers, very useful.

I predict that the new generation of model boat builders will be using brushless motors almost exclusively in the years to come.

Take a look at the Giant Cod website for an example of what's available.
Liked by ralphwilmot
#5

Brushless Motors

HI Dave,
it was a moment of inspiration that took my thoughts in the
direction of the brushless motors, I have just retired and was thinking
about a project to get momentum back into my various power models.
as of recently model yachts has been my passion
thank you
Ray
#4

Brushless Motors

HI Ray
Probably wise. if you are considering a fast 34" planing model brushless are very good, especially if you use LiPo batteries as the setup produces very little weight and the model really skims along.
Dave
Live long and prosper

Dave
#3

Brushless Motors

HI Dave M,

Thank you for your reply, and have noted your comments on the use of
brushless motors being normally the domain of fast electric boats considering
this I will not proceed any further on this train of thought, I do not think
other pond users would appreciate a tug approaching on the plane

Ray
#2

Brushless Motors

HI Ray
Outrunner brushless are usually best in model boats. You will need a brushless speed controller and one that is reversible. Many sellers will say their controller is reversible (it is if you change over two of the three wires) but you need one that has built in reversing. if you buy a marine controller (water cooled) this should be OK. I am intrigued why you want to fit one into a Tug as their main use is in fast speed models. I suppose you could use some form of reduction unit but brushless motors normally run at a few thousand revs per volt and are not noted for slow speed. Please do let us know how you get on and advise details of your set up. Good luck.
Dave
Live long and prosper

Dave
#1

Brushless Motors

I am considering replacing a set of two MFA 500 torpedo motors In my tug
with brushless motors,

having no experience with brushless motors, Is there a rule of thumb that
requires to be applied In calculating the appropriate replacements & speed
controllers, any advice appreciated
Ray

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