Motor high pitch noise

[Queequeg QuintParticipant @queequegquint38270]

35 inch lobster boat.  MFA Como 800 turning a 55mm brass 4-blade prop. 

 

I tried her in the bathtub the other day.  It is VERY POWERFUL.  Only thing is, when I go forward, the motor makes a high pitch noise.  I have to push the throttle quite a way up to get her turning, then I can back her off a bit.

 

BUT, going reverse, she starts turining the prop immediately with the throttle at near neutral. 

 

What do you think the problem with forward is?  It’s a new motor, so I wonder if it needs some more breaking in?

[Queequeg QuintParticipant @queequegquint38270]

[ashley needhamParticipant @ashleyneedham69188]

Q. I am wondering if the thrust from the prop is being transferred on to the  motor…thus pushing the motor shaft on to its bearings…and causing binding/drag   ? This wopuld accoint for the noisy motor in one direction only.

 

I would check the shaft  adjustment if i was you. Also check the shaft nuts are done up tight, as this could cause a loss of clearance as well.

 

Some people run in their motors…i dont bother personally for these (relatively) cheap can motors, and in any case I doubt you will be using the full 5000 rpm much, as you say, its quite a powerful motor, My Fantome has these 800`s fitted on 50mm brass 3 blade props, and the motor spins up to full revs almost instantly you floor the throttle ! (no squealing) and the boat leaps forward very nicely.

 

Ashley

[Mike DavidsonParticipant @mikedavidson22772]

Hi there, it’s me again, Mike Davidson from Plymouth, I have been giving your problem a lot of thought, and I have a vague ideathat I know what is wrong, that is that there is a slight error in the setting up of the ESC I suggest you look at the mtronics website and download the setting up of the ESCand the throttle control I suggest you print off the procedure and go through it precisely with a friend who can readthe instructions while you carry out the actions. The clue you gave me was that the motor did not react straight away, but you needed to push the throttle more forward before the motor reacted. This points to a threshhold in the ESC program not beiNG SET RIGHT, and that you had to override the setting before the controller saw the slow ahead demand properlyIonly vaguely remember the setting up of my controller from the past, and the electronics was very stubborn and did not want to remember the setting points correctly, Have a go, and let me know how you get on. best of luck, mike davidson.

[Queequeg QuintParticipant @queequegquint38270]

Thanks.  I will re-enter the setup process when I get a chance.  I’ve been running the motor on slow speed for a while, and it seems to be getting a little bit better.  For example, it’s capable of turning the prop foward at a slower throttle setting now.  But I still need to push the throttle about 1/3 the way toward full throttle before she starts turning forward.  But reverse is fine.

 

 

[Queequeg QuintParticipant @queequegquint38270]

Here’s a video of the bathtub test.  You can hear the MFA Como 800 singing when it tries to go forward.

 

 

 http://www.youtube.com/watch?v=TTHJf7vlrXE

[ashley needhamParticipant @ashleyneedham69188]

Q..i see what you mean, on the video..it definitely sounds like ESC whine…dotest es it make the same noise when not under load??? if you were to uncouple the engine…and have it running in the boat does it make the same noise??

 

Ashley

 

nb. the traditional  bath test i have found gives a very false impression of likely speed and apparent power. Sushing water all over the bathroom does not neccessarily lead to stunning performance. Or perhaps i fill the bath up too much??

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