Ah alright. I remember someone had suggested the varnish somewhere. Ok.

 

Any electrical problems in the motor seem to be gone. I runned it full speed etc. no problems and no sparking (there was significant sparking before at half speeds). The problem is that the motor flywheel is making a lot of noise, probably more than before. Please advice. Will post a video and full analysis later to demonstrate.

Edit: Note that directly inside the flywheel is the fan. The noise may be attributed to the fan too. I don't know, but the noise is definitely coming from over there. The type of noise if like this one (notice that periodic turning echo):

I think it is because the flywheel is loose..

 

Now you're having me on!
Max.

 

Why did i outsmart you? (not sure this is the right word) Did you mean i was right that the flywheel may be loose?

 

The utube video is of a (noisy) internal combustion engine on a motor mower of some kind!
Showing starter and flywheel ring gear.
Max.

 

Yeah. I meant that the TYPE of noise was similar to mine (not the intensity). But probably that video wasn't a good example. Anyway, i believe that the flywheel is loose. I will update soon.

 

I have uploaded a video here:

-video removed-

You can hear the loud noise on varying speeds. Note that 16km / h is the highest speed.

I jumped on the motor and walked @ 4km / h for about 30 seconds. But the belt did not feel stable. I had just lubricated it though, so that may be the cause. But i wouldn't count on it.

Now, that noise not only sounds really loud but also suspicious of other potential issues. Therefore i won't be riding this treadmill for running until it is fixed. However all other electrical issues on the motor and the MCB seem to have been resolved. Maybe i myself have stressed mechanically the motor while trying to remove the flywheel, or while reassembling it (because it really took me about 3 hours to do it, it was such a PAIN). Unfortunately, I neither have the proper heavy duty tools to troubleshoot this any more, nor can i spend more time on it.

Maybe i will call a technician to take a look at it and tell me his opinion. I have a feeling though he probably won't know what to do and just tell me to replace the motor & / or other parts. So that's it. The story did not have a very happy ending. Maybe i will go running outside, maybe i will register on a gym. We'll see.

Thanks for the help. I appreciate it.

 

Sounds to me like some severe mechanical problem, but I would not think it is the motor, but its a job to diagnose from a distance.
Max.

 

Can we assume the motor is quiet when you run it at high speed without the belt connected?

If it does .... then remove the treadmill ... and connect each stage, ensuring each successive stage doesn't increase the noise. You will discover the "mechanical" noise maker soon enough.

 

@JoeJester

No the motor is making that noise regardless. I checked. It's the flywheel, or the fan.

 

I don't really see how the flywheel is making that noise, unless it is the keyed on variety instead of the threaded on kind.
If keyed, then it could have worn some slop from flywheel to shaft.
The flywheel is usually just one solid steel piece.
Max.

 

Well what else could possibly create this noise then? I can hear it clearly it's coming from somewhere in there.

I do not know the difference between these two types. But i believe threaded means that it's connected with the rotorshaft with threads? If so, then no, the Flywheel is simply firmly attached around the shaft. Yes exactly the flywheel is just one solid steel piece. I can hear it while it's turning, or there may be something else in it. But it's impossible to remove the flywheel right now and see. I don't have proper tools and i may cause more damage.

 

Sounds to me like some severe mechanical problem, but I would not think it is the motor, but its a job to diagnose from a distance.
Max.

You mean that you don't think it's the motor + flywheel housing right (i have shown you the motor parts and they were fine and all inside)? Well what else could it be? What else is turning around fast and causing noise? You want me to remove the MCB and motor from the treadmill and run them someplace else to see if it's still coming from the motor? That is not such a hard job. I could check that within ~15 minutes.

 

Why not just take the belt off and see if the motor runs smooth without the noise, if it IS flywheel connected it should show up there, also if it is in the idler pulley.
There should normally be no moving parts on the flywheel.
Max.

 

I have checked that already. That is what @JoeJester above suggested. But i had already done that myself to test the noise. And yes it is making the exact same noise without the belt, or pulley connected.

The pulley is fine. Yes there should be no moving parts on the flywheel.

 

Well the only thing left is to run the motor from a smoothed DC supply, it would have to be level controlled as you could not put straight 90vdc across the motor with the flywheel attached.
The ideal for this is a Variac and and a bridge rectifier, if you know of someone with this you could set up a test.
Max.

 

Hmm, I will keep that in mind. I have a variac and spare bridge rectifiers myself, but i will look into it some time.

 

If the motor is disconnected from the belt etc and still makes the noise then the only possible causes I can think of are
1) loose motor mountings,
2) motor shaft bearing wear or excessive shaft end float,
3) out-of-balance flywheel,
4) out-of-balance fan,
5) loose flywheel,
6) loose fan,
7) something obstructing or rubbing on either the fan or the flywheel,
8) worn brushes (if a brushed motor).

 

Hmm, I will keep that in mind. I have a variac and spare bridge rectifiers myself, but i will look into it some time.

That is all you need for a fairly definitive test of the motor, take the belt off first.
Max.

 

Can you pull the fly wheel off and run it again?