Servo motor noise

[dikman]

That sort of reply is pretty typical when dealing with Chinese companies, they generally try to avoid refunds/returns as much as possible. I have had issues in the past and have tried to get help from ebay/paypal and they usually insist that I have to return the goods first at my expense (which can be an expensive proposition). 

I'm a bit surprised, I thought Vevor were better than that, I guess not.

[Hidden]

  

10 hours ago, AlZilla said:

It doesn't make it with the belt off but does with the belt on. It's got to be a bearing. Take their 70 euros, replace the bearings and never buy another vevor product.

That's what I'll do. Just ordered some bearings and accepted Pedro's third offer :') thanks for the advice, @AlZilla and everyone else.

Edited October 20, 2023 by Hidden

[dikman]

I think you made the right decision, you've probably avoided a lot of stress/messing around/anguish! I was in a similar situation once over a $450 mini-lathe, dealing with the chinese company was frustrating and Paypal were unhelpful, refusing to acknowledge my consumer rights under Australian Consumer Laws. It took me three months and then only after I got the Australian financial authorities involved did Paypal relent and give me a refund (grudgingly, I must add).

I should have taken the company's best offer!

[Agarbers]

I am late to the party but it sounds like the rotor is rubbing against the stator. Look for wear marks on both.

Rotor:

Stator:

 

Or the bearing housing may not be true/out of round and allowing the bearing to move. Look for wear marks there.

Lastly, like Northmount shows, the bearing may have been damaged during assembly. If it was driven on with a hammer, brinelling may have occurred. Installing a bearing takes special tools to prevent this. If the installer used hammer blows on the outer race to push it down the shaft, damage could have occured. 

[GerryR]

There would be definite and obvious scrape marks on those components, but it does bring up a point about the bearing slipping in the bore.  Loctite makes a product that you can put on the bearing OD so when put into the housing bore, it will prevent it from slipping in the bore.  The same can be used on the shaft-to-inner-bore interface, but you should be able to tell by the fit, when assembling, whether it is needed or not.  Just something to keep in mind.

[stitchgearhead]

In my experience, when metal touches metal, it never does that CHWUNK sound. Screech, scratching sound (if speed at metal/metal interface is high), or dry blow, knocking sound if it's a consequence of too big a gap between parts that should be closely adjusted (like in conrod or crankshaft bearings).

That sound seems very much, to me, to come from the pulley/belt interface.

Does the noise change, in any way, when you increase/decrease belt tension?

Do you have any way to try the motor with a (even if temporary) belt of another kind? Even if only for a few revolutions? I'm betting that a different belt (preferably narrower) will produce a very different sound.

If I were in your shoes, I would try another belt, of any kind, before deciding anything. Maybe even one of those round leather belts for old machines - should last long enough to draw conclusions.

Also, if it turns out to be the pulley, any machinist should be able to rectify it fairly easily, so as to be perfectly round and concentric relative to the axle bore.

Please, let us know what happened with the new belt. I, for one, am curious.

Daniel

 

[Hidden]

Hi Daniel, the motor makes the noise even with the new belt (both the 3L belt and the SPZ belt). I replaced the bearings now, too, still makes the noise. I ordered a new 45mm pulley too (will need that anyway when I eventually make a speed reducer). Maybe I should try a urethane belt. But I think the whole thing being out of round as suggested above is also a possibility. The investigation continues.

I’m probably just going to buy a new motor, though, and keep this one around as a spare. Considering the Jack 563A from https://www.sewtex.de/Motore--Gestell--Tischplatte--Zubehoer-fuer-Naehmaschinen--Stuehle--Leuchten--Transportwagen--Industriestuhl--Schere/Naehmaschinenmotor--AC-Motor-230-Volt--Industrial-Sewing-Machine-AC-Motor/Servomotor--AC-Servo-Motor-750-Watt--Jack-AC-Motor-JK-563A.html?XTCsid=df442c4e1fdb8a46685e9b04ef093c90 but from a search here on the forums I gather SewTex’s reputation is not so good. Happy to hear any other suggestions (within the EU and under €200, preferably).

Edited October 24, 2023 by Hidden

[AlZilla]

1 hour ago, Hidden said:

I replaced the bearings now, too, still makes the noise.

Well, I'm practically stunned it wasn't a bearing. How about putting the belt onto the naked shaft and pulling some tension against the shaft as it rotates to isolate the noise to the motor or pulley/belt?

[Hidden]

On 10/24/2023 at 11:02 PM, Hidden said:

Hi Daniel, the motor makes the noise even with the new belt (both the 3L belt and the SPZ belt). I replaced the bearings now, too, still makes the noise. I ordered a new 45mm pulley too (will need that anyway when I eventually make a speed reducer). Maybe I should try a urethane belt. But I think the whole thing being out of round as suggested above is also a possibility. The investigation continues.

I’m probably just going to buy a new motor, though, and keep this one around as a spare. Considering the Jack 563A from https://www.sewtex.de/Motore--Gestell--Tischplatte--Zubehoer-fuer-Naehmaschinen--Stuehle--Leuchten--Transportwagen--Industriestuhl--Schere/Naehmaschinenmotor--AC-Motor-230-Volt--Industrial-Sewing-Machine-AC-Motor/Servomotor--AC-Servo-Motor-750-Watt--Jack-AC-Motor-JK-563A.html?XTCsid=df442c4e1fdb8a46685e9b04ef093c90 but from a search here on the forums I gather SewTex’s reputation is not so good. Happy to hear any other suggestions (within the EU and under €200, preferably).

I can get a Ho Hsing G60 for €327 from a (very) reputable dealer in The Netherlands, but it's so expensive (and that's without the needle positioner!). Still kind of tempted to buy it because it seems to be the best motor, just to not go through this whole motor ordeal again lol. That one also seems to actually start at 100 rpm, as opposed to my current 400 rpm start and the Jack's 200 rpm. Decisions... this hobby can get expensive quick :')

[Constabulary]

On 10/24/2023 at 11:02 PM, Hidden said:

Hi Daniel, the motor makes the noise even with the new belt (both the 3L belt and the SPZ belt). I replaced the bearings now, too, still makes the noise. I ordered a new 45mm pulley too (will need that anyway when I eventually make a speed reducer). Maybe I should try a urethane belt. But I think the whole thing being out of round as suggested above is also a possibility. The investigation continues.

I’m probably just going to buy a new motor, though, and keep this one around as a spare. Considering the Jack 563A from https://www.sewtex.de/Motore--Gestell--Tischplatte--Zubehoer-fuer-Naehmaschinen--Stuehle--Leuchten--Transportwagen--Industriestuhl--Schere/Naehmaschinenmotor--AC-Motor-230-Volt--Industrial-Sewing-Machine-AC-Motor/Servomotor--AC-Servo-Motor-750-Watt--Jack-AC-Motor-JK-563A.html?XTCsid=df442c4e1fdb8a46685e9b04ef093c90 but from a search here on the forums I gather SewTex’s reputation is not so good. Happy to hear any other suggestions (within the EU and under €200, preferably).

As I said in an earlier post in this thread. I have two Jack Motors with 750W (563A actually) and they both make this sound. IMO that sound is not really an issue. The oldest is running since 2014 w/o any issues. Really, that "noise" may just sound strange but IMO its actually not an big issue. From what I have witnessed that "noise" is quite common among the "cheaper" 750W motors. IIRC the 550W Jack Servo do not make this "noise".

Just my experience.

[stitchgearhead]

@Constabulary: the sound may just be normal (it is on your motors), but, with small sample population, it is difficult to know for sure if it represents a problem or not. I believe you may be right, some mechanisms are just normally noisy. Unfortunately, I still haven't bought a servo motor, but intend to soon.

I would do, however, a small change that has no negative impact, even if it doesn't change anything: I would put the motor spinning, with no belt, and sand the inside of the pulley with medium, and then fine, sandpaper. Say, 320-400-600. May reduce the noise, and will give the OP an idea of how far out-of-round the pulley is...

Also, there's something that is made on car belts, that is useful for identifying the source of belt noise: with the motor/belt spinning, spread a little liquid on to the belt/pulley interface. May be water or thin oil, but I usually use WD40 or equivalent. If the noise changes, some of it, at least, comes from there. It may also come from the machine pulley (rather than the motor pulley...), so try there too. Just a test...

Anyhow, this may be just as Shakespeare once wrote: "Much ado about nothing". Some people are more sensitive to noise than others.

I do hope this turns out well for the OP.

Daniel.