That screeching noise at certain speeds

[JerryBurks]

I read about this noise here on the forum in a few posts and experience it on my new machine mostly when manually jogging the y and z axis at higher speeds or when the software is moving the bit quickly from one routing trace to another. Lubrication seems to helps a little, but I am beginning to wonder if that is the natural stepper resonance frequency that is described in some stepper motor information web sites (e.g. here )

Any insight how to minimize or avoid that?

Thanks, JB

[jeb2cav]

I notice "more" noise when the FRO is less than 100%. The lower the FRO, and the faster the gantry is trying to move, the higher the noise. I agree that if eveything else is well lubricated and clean, that this is natural for the stepper motors to generate.

For what it's worth - If the FRO is 100%, the only time I get any noise to speak of otherwise is when travelling the lower half of the z axis.

[JerryBurks]

Thanks, interesting observation. Actually I did run the machine mostly around 60-80% FRO.
I will try to reduce the path feed rate and get to 100% FRO.

[Buc]

I agree with Joe. The noise is comming from the stepper motors. Sometimes, when I am paying attention and listing to my machine while doing a 3D carve, it will sound like the machine is playing a tune, comming from the Z axis. Mostly when I am doing a dome shape. Whistling while it works???

Buc

[JerryBurks]

The snarling noise got worse over time, so it was unlikely to be the steppers.
Now I tried some regular thin oil on the lead screws instead of the silicone dry film lubricant and guess what...the noise is completely gone at any speed.
Let's see how long that lasts and how much dust it will attract.