questions about ESC's

don_jarr · 07-03-2008

Hi all

I have now finished my boat and I am just adding two esc’s one for the main drive power and one of the smoke generator, and I have several esc’s knocking around so tried a couple out.

I tried a Mtroniks one and find at low rpm it makes the motor give off a sort of high pitch whistling come whining noise, (most distracting,) and then I tried the electronize one it doesn’t do the whine or whistle, but makes the motor click or creak at low rpm.

The main drive motor is a gruapner speed 800bb torque, and the smaller one is just a 12v dc fan.

Any info or advice on how to stop this is possible, or an esc that doesn’t do it would be much appreciated. I put lots of effort into getting this really well detailed for appearance when on the pond, and having it whine and whistle or creak was not part of the plan.

Many thanks

Don

bogstandard · 07-03-2008

If I was you, use the 'groany' one, it is much less noticeable on the water.

What you are seeing, sorry, hearing, is the quest for efficiency and 'improvements' in technology.

In the 'old' days all the manufacturers used the ZN409 chip for their speed controllers, a dedicated servo chip, but they were limited as to how they pulsed the electrical signal to the motor. But they did give a nice quiet motor.

All manufacturers gave up on this many years ago and went over to new technology to give better control to the motor, the only problem is the one you have now, they are so efficient, they give great speed control but you just got to accept the noise. Some motors are less prone to it than others, but high performance ones suffer the most.
Electronize do one where you can switch between high and low frequency control, so you can have both noises if you want to, but not at the same time.
A sign of technology, one step forwards, two steps back.
A nice loud sound board can cover up most of it.

John

**Bunkerbarge** · 07-03-2008

I would keep your options open for now until you get to try it on the pond. You might just be a little bit over critical at the moment and picking up on every tiny thing that may not even bother you when it is on the water. Don't actually fix them into the boat until you have tested them on the water and you can then best decide it the noise is an issue or not.

As an example I have a Slipways Envoy tug with a geared hectaperm motor. When I first tried it out I was very dissapointed with the noise it made but when I got it on the pond and I got used to it I don't even notice it now.

Maybe even a bit of sound insulation is all it might require on the inside surfaces.

don_jarr · 08-03-2008

Hi all

It seems it’s partly amplified by mounting the motor. If you hold the motor in your hand the noise or vibrations isn’t really noticeable, but as soon as you rest it on something, the noise is amplified through whatever its on. The boat hull being wood coated in fibreglass amplifies it a lot.

Now I have the motor mounted sitting on bubble wrap as it’s the only thing that keeps the noise to a minimum but the motor which I got wrong and is a 900bb torque is very powerful but very quite in terms of when spinning. My only hassle now is how to fix the motor to stop it torque twisting when the props in the water. I had thought of those little rubber mounting things with a threaded section either side of the rubber cushion, then hang the motor rather than mount it.

I will however try the Electronize switching between high and low frequency control as it has that switch on it.

Many thanks for your help.

Don

jankers · 11-03-2008

The sound can be very distracting, especially so when testing on the workbench.

i have used sheet rubber (from a cobbler), dense foam, anything i could lay my hands on to dampen the sound. I have yet to try old car inner-tube (from your local garage), but all my experiments have been with 360 or540 type motors, yours is more powerful.

J.