Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: ESC  (Read 3524 times)

Angus64

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 51
  • Location: Tasmania
ESC
« on: January 31, 2017, 08:35:15 pm »

Hi boys. I have fitted a Viper 75 Amp ESC to my boat hoping to get a smoother operation of the boat, The ESC worked well although I had a few issues setting it up. The problem is it has a high pitched whine coming from from the ESC when I accelerate, the noise slowly fades out when  it reaches full revs. no noise in the neutral position. It is quite loud & can be heard above the diesel sound generator. The motor has a capacitor fitted bridging the negative & positive brush wires to stop noise.  Anyone out there had any problems with  Viper Esc.
Angus.
Logged

mrlownotes

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 404
  • Location: A bit NorthWest Cambridgeshire
Re: ESC
« Reply #1 on: January 31, 2017, 09:24:15 pm »

Been there, bought the T-shirt. Ended up trying several ESCs and 3 alternative motors. It was 'suck it and see' time.

The whine comes from the motor itself as it is 'pulsed' at whatever frequency the ESC is using. Full throttle has no pulsing so the whine disappears.

The following link to my previous thread has some technical explanation.

http://www.modelboatmayhem.co.uk/forum/index.php/topic,53135.msg547032.html#msg547032
Logged
Bintur Ellenbach

Tug-Kenny RIP

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,625
  • Location: Newport. S Wales
Re: ESC
« Reply #2 on: January 31, 2017, 09:29:00 pm »

There has been a lot of discussion on this subject.  It is due to a frequency being transmitted to the motor housing and it rattling in sympathy as mentioned above.

There is no way it can be eliminated but I have found  (in my case)  that a piece of felt wrapped around the motor body reduces it considerably.  When out on the water it is unnoticeable when the craft speeds up.   :-))

ken
Logged
Despite the high cost of living   .......... It remains popular

nivapilot

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 295
  • re-invented rc boater
  • Location: Sarisbury Green
Re: ESC
« Reply #3 on: February 05, 2017, 08:46:26 am »

I do get a little noise from my Viper 15, but not enough to drown out a sound generator, and about ten ft away, I can't hear it.
Logged

malcolmfrary

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 6,027
  • Location: Blackpool, Lancs, UK
Re: ESC
« Reply #4 on: February 05, 2017, 10:05:18 am »

As discussed in lots of other threads, the ESC gives a switched output at a constant frequency.  The motor converts some of this to sound.  The "noise suppression" is nothing to do with sound that you hear.  It is there to stop the unwanted generation and broadcasting of unwanted radio signals which are a few million times as high pitched.
Since it is pulsed power applied to the motor that makes the sound, it will be quiet at neutral when no power is being applied.  Personally, I like to hear that something is going on when I start to move the stick - it reassures me that the thing is going to work.
Logged
"With the right tool, you can break anything" - Garfield

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,187
  • Location: North London
    • Dive-in to Model submarines
Re: ESC
« Reply #5 on: February 05, 2017, 10:32:33 am »

There are some speed controllers out there that pulse at a much higher frequency, around 19khz, which is inaudible. However I believe the efficiency drops off a bit, and I would guess you would get more heating in the FETs as the switching losses would be higher.


Mike Stothers could give a much deeper insight into this.
Logged

Martin (Admin)

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 23,366
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: ESC
« Reply #6 on: February 05, 2017, 12:26:01 pm »

There are some speed controllers out there that pulse at a much higher frequency, around 19khz, which is inaudible. However I believe the efficiency drops off a bit, and I would guess you would get more heating in the FETs as the switching losses would be higher.

Could you point a couple out?   :-)
Logged
"This is my firm opinion, but what do I know?!" -  Visit the Mayhem FaceBook Groups!  &  Giant Models

Subculture

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,187
  • Location: North London
    • Dive-in to Model submarines
Re: ESC
« Reply #7 on: February 05, 2017, 10:16:49 pm »

Not exactly spoilt for choice, Martin.

Here's one pulsed at 16khz- old TV tubes used to whistle at that frequency, and most people couldn't hear them.

http://www.servonaut.de/shop/product_info.php?info=p254_fahrtregler-mfx.html
Logged

Angus64

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 51
  • Location: Tasmania
Re: ESC
« Reply #8 on: March 06, 2017, 01:06:17 am »

Hi Boys. We got some good weather over here the last week, So I put my boat in the water to see how much noise I was going to get from ESC when sailing the boat,Got a bit of a surprise when the noise was barely audible in the water. I guess the water jacket (a copper coil wound full length of the motor) when full of water was deadening the sound from the motor. The Viper 75 is a great unit for the sized motor I use, very good control of the speed right through the range from neutral to full speed & the 75 amp in reverse made a big difference when maneuvering the boat in small spaces & up against my pool noodle I use as a buffer against the rock steps at the lake where I sail here in the Penguin park.
Very good unit for bigger boats very happy with unit.


Angus.       
Logged

FrozenRabbit471

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 135
  • Long may you big jib draw
  • Location: Lloydminster, Alberta, Canada
    • My Instagram
Re: ESC
« Reply #9 on: April 15, 2017, 11:47:12 pm »

Hi all,


I am building a Nordkap Kit. My first boat.
To avoid initial cost of RC components, I am thinking of using some spare parts I have from the 1:10 scale Crawler/Trail Truck hobby I'm into.


Until I buy better marine suited gear, can I use the following?
1 Axial 35t brushed motor (direct to the single prop shaft)
1 AE2 Axial esc
1 Tactic 2 channel receiver
1 Tactic high torque servo
**and the biggest question, will a 2 channel  pistol grip transmitter work "for now"?


It all seems laughable, but it's just to get me running. It's my first boat. I'll press the trigger very gently as the esc isn't programmable. I don't think.


Thanks
Logged
Better to have it and not want it, than to need it and not have it

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: ESC
« Reply #10 on: April 16, 2017, 08:18:59 am »

Hi all,


I am building a Nordkap Kit. My first boat.
To avoid initial cost of RC components, I am thinking of using some spare parts I have from the 1:10 scale Crawler/Trail Truck hobby I'm into.


Until I buy better marine suited gear, can I use the following?
1 Axial 35t brushed motor (direct to the single prop shaft)
1 AE2 Axial esc
1 Tactic 2 channel receiver
1 Tactic high torque servo
**and the biggest question, will a 2 channel  pistol grip transmitter work "for now"?


It all seems laughable, but it's just to get me running. It's my first boat. I'll press the trigger very gently as the esc isn't programmable. I don't think.


Thanks


In answer to all your questions..yes. The crawler motors are a very good option, being slow revving ( relatively ) with high torque. The only possible slight issue may be with the ESC.  Does it go immediately into reverse or do you have to 'double dip' the throttle trigger? If the latter, you may occasionally run into the bank or other models till you get used to this on a boat, which just keeps moving forward till you engage the motor in reverse.
Logged
Listen politely, nod approvingly, then do what you want, works for me!

FrozenRabbit471

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 135
  • Long may you big jib draw
  • Location: Lloydminster, Alberta, Canada
    • My Instagram
Re: ESC
« Reply #11 on: April 16, 2017, 02:25:47 pm »

Yes, this would certainly pose a potential risk. Fortunately, (or unfortunately) there are no other RC boaters within hours of me. If I had a Castle esc I could program it to behave perfectly, but that will come as I move forward.
Thanks unbuiltnautilus
Logged
Better to have it and not want it, than to need it and not have it

malcolmfrary

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 6,027
  • Location: Blackpool, Lancs, UK
Re: ESC
« Reply #12 on: April 17, 2017, 09:28:07 am »

Reading the instruction sheet - http://docs.axialracing.com/instructions/Electronics/AX24259-i001_-_Manually_Programming_the_AE-2_ESC.pdf - it looks like you can't program the brake out.  That could be an annoyance.  On a boat, reverse is the brakes, forcibly stopping the motor doesn't really do a lot.
Logged
"With the right tool, you can break anything" - Garfield

FrozenRabbit471

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 135
  • Long may you big jib draw
  • Location: Lloydminster, Alberta, Canada
    • My Instagram
Re: ESC
« Reply #13 on: April 17, 2017, 11:58:31 am »

gotcha. like a real boat. no brakes.
Logged
Better to have it and not want it, than to need it and not have it
Pages: [1]   Go Up
 

Page created in 0.093 seconds with 21 queries.