Weird noise with T200 thrusters

Hi everyone,
I post here (I’m not sure I’m in the right place) because I have a problem with T200 thrusters. I noticed they were making a weird noise at low speed. It’s like a tac-tac if something rubs.
Here is a video of my robot (equipped with 3 T200) where you can hear this sound :

https://photos.app.goo.gl/cxLfnHAbng2N6tSZ7

Is it normal or is there a fault?
Thank you for your help
Silvain

Hi @Silvain,

It sounds like the thruster bearings may be on the looser side, but this still falls under the range of normal. Due to the plastic bearings used, tiny differences in the fit between the bearing and shaft can cause large differences in the sound signature of the thrusters. No two thrusters will sound exactly alike, and as the thrusters wear over time the sounds will change. If this noise is bothersome it is possible to swap the bearings and get a tighter fit.

-Adam

Hi @adam,
Thanks for your reply.

So you confirm that there is no problem and that the thruster works just as well?
By dismantling it, I saw that the plastic ring (what you must call bearing) is not glued unlike other thrusters that I had. Is it normal ? It does not matter ?

Unless you are seeing some other issue, just different noise is not an indication of a problem due to the aforementioned quirks of the plastic bearings.

Some bearings are glued in place while others are just press fit depending on the exact dimensions and fit, the presence of visible glue or not is not an issue, just a production variation.

-Adam

Hi @adam

Thanks for you reply and your confirmation.

I take this post to expose another problem, always on the T200s.
We order quite often and in some thrusters, there are “holes” in the varnish of the rotor (see picture) which causes rust in seawater.
Is there a way to avoid this?

Just a small clarification:
It does not matter if the ring moves (it gets removed if you remove the rotor) ?
There is no need to stick it to the glue?

The bearing should not be loosely popping out. Have these thruster been run dry in air at all? A loose bearing shouldn’t cause an issue in our experience due to the geometry around it, but it would be a good idea to glue it in place if it does not stay in on its own after being pressed back in.

Were those rotors received in that condition on new unused thrusters, or did those dings in the coating occur after some run time?

I just found you are also having an email conversation regarding these same topics with one of our distributors. It would be best to keep the conversation to the existing email thread for the sake of clarity and to avoid any confusion.

-Adam

Hi Adam,

Ok, thanks for your reply for the bearing.
In our case, the bearing falls alone if we turn the stator. These thrusters never run in the air and we run it less than 2mins into the water.

For the holes in the varnish, we received them like new but actually, we are already in discussion with your distributor for this problem. And we turn to him if it requires a replacement. But I’m wondering if it’s normal for these holes to be there or if it’s a manufacturing mistake ?

We just start a call with your distributor and Lindey.

I assume you are talking about turning the black rotor? The green stator should definitely NOT be turning in any circumstance.

The black coating on the rotor should be continuous and uninterrupted, if there are visible dings on a new rotor as in your image this is damage that may have occurred at some point in the production process.

-Adam

Yes, sorry. I was talking about flip (et not turning) the stator (green) vertically which causes the ring to fall (when the thruster is disassembled).

Thank you for your clarification on the varnish.