Noise stepper motors

Hello.
Faced with such a problem.
When driving stepper motor noise as if the sand is poured, twitch, skip steps in them. What is it?
I use the Repetier. Since the display on the Marlin does not work (
duplicate engines work in different ways. Even not always start at the same time.
Video

Edited 1 time(s). Last edit at 09/01/2016 02:13PM by pirat777knj.

Video is private, can't see it.

Stepper motor noise can be caused by: running at full steps(higher the microstepping, the quieter it runs), mis-wired, insufficient stepper current, mechanical problems, stepper driver design.

All of the above is possible. It was ramps 1.4 and it all worked fine.
Step 1/8 division. Engine in order. Hand scroll and no sporotivleny not felt.
The problem surfaced on RADDS.
Video opened.

The last time I had a similar noise, the stepper driver current was too low. Setting stepper current with A4988 & DRV8825:[reprap.org]

I tried to change the current. The effect has changed, but not gone (to try different current. And below normal and above. The speed of 60.
And can not be so that the voltage from the board Due enough for the driver DRV8825...

Have you tried a higher microstepping, like 1/16 or 1/32?

Today I tried. The overall effect remained. All the same noise, only smaller.

I finally found the thread I remembered here talking about the exact same problem - with a lead-screw driven printer.

The lead screw will transmit the noise from the stepper driver much more than belts do.
The amount of noise varies greatly with the variety of stepper driver, how they are tuned, the microstepping, and the amount of current.

It is well described here:
[forums.reprap.org]

the_Digital_Dentist used a DSP based external stepper driver to help solve the issue.

The DSP drivers are similar to these.
They allow either automatic or external program based tuning to reduce the motors resonance points.

Since that time I also used 3 DSP drivers on my printer, and they can made a big difference - allowing the motors to run much more smoothly and quietly.

32 bit electronics (Smoothieboard or Duet) will also allow higher microstepping (and resulting faster step rate) without jitter.

Using high microstep rates (over 16) on an 8-bit controller can be asking for trouble though - especially if a graphic LCD is used - they may not be fast enough to keep up - you may see inconsistent step timing, stalls in the movement, and this can cause problems in the print, and even missed steps/shifted layers.

For my printer I definitely needed to use at least 16x microstepping, as lower microstepping was much louder.
I should actually test running at higher microstep rates than 16 to see if it will improve it further - since I have a Smoothie and it can handle it.

---

My printer: Raptosaur - Large Format Delta - [www.paulwanamaker.wordpress.com]
Can you answer questions about Calibration, Printing issues, Mechanics? Write it up and improve the Wiki!

Paul Wanamaker
This I know. But the gaps are unusual and unstable movement of the screws.
Again, this was not on the RAMPS 1.4

OK,

I listened to the video over and over. It sounds like loose bearings rattling.

But I understand now - the problem only started when you changed to RADDS - so it's the drivers causing it. What model stepper drivers are you using?

There is a huge difference in the noise from various drivers. DRV8825 can be the worst, Allegro drivers better (depending on tuning).

See these videos about the Silent Step Stick. I haven't use them but they seem quieter. If interested in them then search the forums for other's experience.:

[www.youtube.com]
[www.youtube.com]

Guys. I found out the reason for this phenomenon.
Installed firmware Marlin. It is not such a disgrace. Everything is working!
It is not clear why there is a problem on the Repetier?