motor upgrade

[Nick]

Hi, I have one of these "toy" twin 380 motor speed boats. It's fun, but
I want a little more out of it. What motor can I replace the stock,
cheap, 380's with to give it more speed? I don't understand what 380,
400, 480, 540 etc is.

Thanks in advance,

Nick
--
http://www.lake-district.info

[Kevin R]

the number is the length of the can a 380 is 3.8cm long a 540 is 5.4cm ETC
but as they get bigger numbers the diameter of the can increases and also
the shaft size and also the amount of current the motor takes so the battery
life decreases and you might need a bigger speed controller and to get the
same run time a bigger battery
so you need to work out a way of mounting a bigger motor and if it will
connect to the prop shaft
Kevin
"Nick" <neverchecked@blueyonder.co.uk> wrote in message
news:yL8Nd.8364$8B3.6601@text.news.blueyonder.co.u k...
> Hi, I have one of these "toy" twin 380 motor speed boats. It's fun, but I
> want a little more out of it. What motor can I replace the stock, cheap,
> 380's with to give it more speed? I don't understand what 380, 400, 480,
> 540 etc is.
>
> Thanks in advance,
>
> Nick
> --
> http://www.lake-district.info

[Nick]

Kevin R wrote:
> the number is the length of the can a 380 is 3.8cm long a 540 is 5.4cm ETC
> but as they get bigger numbers the diameter of the can increases and also
> the shaft size and also the amount of current the motor takes so the battery
> life decreases and you might need a bigger speed controller and to get the
> same run time a bigger battery
> so you need to work out a way of mounting a bigger motor and if it will
> connect to the prop shaft
> Kevin

Tnx for that. Would I be correct in assuming that I can get better
quality (ie faster) 380's? Also, would a 400 be close enough to fit
(with perhaps only minor modification), not much more draining on the
battery, but at the same time - that little bit quicker?

tnx, Nick


> "Nick" <neverchecked@blueyonder.co.uk> wrote in message
> news:yL8Nd.8364$8B3.6601@text.news.blueyonder.co.u k...
>
>>Hi, I have one of these "toy" twin 380 motor speed boats. It's fun, but I
>>want a little more out of it. What motor can I replace the stock, cheap,
>>380's with to give it more speed? I don't understand what 380, 400, 480,
>>540 etc is.
>>
>>Thanks in advance,
>>
>>Nick
>>--
>>http://www.lake-district.info
>
>
>

[Nick]

Nick wrote:
> Kevin R wrote:
>
>> the number is the length of the can a 380 is 3.8cm long a 540 is 5.4cm
>> ETC but as they get bigger numbers the diameter of the can increases
>> and also the shaft size and also the amount of current the motor takes
>> so the battery life decreases and you might need a bigger speed
>> controller and to get the same run time a bigger battery
>> so you need to work out a way of mounting a bigger motor and if it
>> will connect to the prop shaft
>> Kevin
>
>
> Tnx for that. Would I be correct in assuming that I can get better
> quality (ie faster) 380's? Also, would a 400 be close enough to fit
> (with perhaps only minor modification), not much more draining on the
> battery, but at the same time - that little bit quicker?

Actually, what is confusing me is that the 380 is rated for 26,000 rpm
(no load) whereas the 400 is rated at 16,400 rpm. I know this is "no
load" but I want a motor that will turn the prop quicker...

[Kevin R]

"Nick" <neverchecked@blueyonder.co.uk> wrote in message
news:zDbNd.8460$8B3.47@text.news.blueyonder.co.uk. ..
> Nick wrote:
>> Kevin R wrote:
>>
>>> the number is the length of the can a 380 is 3.8cm long a 540 is 5.4cm
>>> ETC but as they get bigger numbers the diameter of the can increases and
>>> also the shaft size and also the amount of current the motor takes so
>>> the battery life decreases and you might need a bigger speed controller
>>> and to get the same run time a bigger battery
>>> so you need to work out a way of mounting a bigger motor and if it will
>>> connect to the prop shaft
>>> Kevin
>>
>>
>> Tnx for that. Would I be correct in assuming that I can get better
>> quality (ie faster) 380's? Also, would a 400 be close enough to fit (with
>> perhaps only minor modification), not much more draining on the battery,
>> but at the same time - that little bit quicker?
>
> Actually, what is confusing me is that the 380 is rated for 26,000 rpm (no
> load) whereas the 400 is rated at 16,400 rpm. I know this is "no load" but
> I want a motor that will turn the prop quicker...
I must admit I am more of an electric plane modeller than boats and the
difference a 480 makes over a 400 is quite a big step, 1 thing that will
boost the speed is running on another cell so if you are running a 6 cell
pack try running on 7 as 1.2volt increase make a big difference as well but
it could damage the electronics in the boat so be warned

[William]

"Nick" <neverchecked@blueyonder.co.uk> wrote in message
news:zDbNd.8460$8B3.47@text.news.blueyonder.co.uk. ..
>
> Actually, what is confusing me is that the 380 is rated for 26,000 rpm (no
> load) whereas the 400 is rated at 16,400 rpm. I know this is "no load" but
> I want a motor that will turn the prop quicker...

The trick is that under a given load, the 400 will turn faster.

As someone else suggested, you can get a bit more out
of your existing motors by adding a cell (maybe two) to
the battery pack (that drives the motors, if the electronics
are also driven from this pack, you'll have to do some
rewiring). The danger is overloading the speed controller
so watch for overheating there.

Of course if you upgrade the motor, then the speed
controller is going to be carrying a bigger load anyway.

Another element is the battery chemistry. Alkaline cells -
non-rechargeable - give about 1.5 volts, but it degrades
quickly under load and as the battery warms up. NiCds or
NiMh batteries have a lower cell voltage but maintain it
better and can provide more power. Sealed lead-acid
batteries (I'm partial to the D-sized "Gates" cells) can
give a lot of power (and at 2V per cell) but do add weight.
-Wm

[garyg]

"380", etc. is the diameter of brush-type motor "can" in millimeters. Most
motors are by Mabuchi.They are also rated as 6-volt or 7.2 volts. A 6-volt
motor will turn up higher rpm than a 7.2 on the same battery pack. A larger
diameter motor will pull more amps and deplete your battery pack quicker
than a smaller one. You can get more power with same motor by using a
battery pack with one more cell but that will probably shorten the life of
the motor.Brush motors usually cost about $10 so you can replace them as
needed. Brush-type motor brushes overheat and wear down quickly when run at
higher than intended voltage/current draw. To properly upgrade, you will
need to mount a larger motor and probably a larger amperage/capacity battery
pack with maybe one more cell.. You might need to increase the size/pitch of
the prop. If you install too big/heavy a motor and battery pack, the boat
will ride lower in the water and may not run as nicely at lower speeds.
Hobby Lobby sells some easy to install geared 400 and 600 motors with
stuffing box and prop. Gearing allows using smaller motors with bigger
props. HL also sells coiled brass tubing to be installed on the motor can
for water cooling which may help longevity of motors. Brushless motors can
tolerate higher voltages ( more cells) and produce much more power for a
given size. Brushless motors are much more expensive and require much more
expensive electronic speed controls. I am an electric plane flyer and
haven't heard much about use of brushless motors in boat models yet.