Adventures with silent stepper drivers

I find the sound of the Nomad’s stepper motors to be really annoying and after watching this video it seems that this is a problem that can be solved by more advanced stepper drivers, at least for some machines like that laser cutter.

This came up briefly here but I didn’t see the apparent noise advantage of the Trinamic stepper drivers raised.

Does anyone have any clue whether replacing the stepper drivers will or won’t make the steppers quieter? To be clear, I think I’d end up replacing the Carbide Motion board with something completely different, I don’t have any crazy ideas of altering the existing board or anything.

On a related note, does anyone know what kind of steppers these are (e.g. amperage and torque rating)? What I know so far:

  • They’re NEMA 17-sized
  • They’re ~40mm long
  • They have to be 2.5A or less and 8-35V because that’s what the DRV8818 supports

Looking at steppers that fit those criteria, they’re probably ~45Ncm and 1.5-2A.

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I did some more research and found these documents from Trinamic:

They claim that the main benefits of the silent tech are had at low velocity but from the second document, it doesn’t look like the drop in torque at high velocities is all that much.

I think I’m just going to have to buy a controller and try hooking it up to the Nomad’s steppers to see what happens.

I noticed the X-axis has 17HS3401A-339IN, “JUGETEK” and “194320” written on it. So it’s made by this company. I can’t find the particular motor there however.

Dropping a little tq probably wont hurt you as the nomad grbl defaults are very conservative.

Shoot, even pushing a 1/4 through steel the stock steppers had no issues. I believe they are 2a around 85oz Nema 17s.

Lost most of what I wrote here before the server died but TL;DR:

  • The stepper drivers on my Carbide Motion board are Allegro A5977 rather than TI DRV8818s.
  • I successfully hooked up Trinamic TMC2209 stepper drivers.
  • Hooking up a new controller to the Nomad’s steppers is fairly straightforward. I was able to hook up both an Arduino Uno running GRBL and an Arduino Due running g2core without any problems.

The Trinamic stepper drivers make a huge difference to the noise levels. At low speeds the steppers are completely silent. At higher speeds they’re very quiet and much less obnoxious than they are when driven by the stock drivers.

So the noise issues I had with the steppers were absolutely the fault of the TI DRV8818 stepper drivers.

If anyone is interested I can try to record a short clip comparing the noise produced by each set of drivers.

The big open question is how the steppers run while cutting. I haven’t tried that yet.

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You’ve been on quiet the quest, Lucas :wink:.

I don’t have a Nomad, but I’d still be interested in seeing some footage that compares the two; better yet, if you have footage with a way to measure sound levels.

Ask and you shall receive.

I’m documenting this to be as reproducible as I can so that anyone who has ideas/critique can suggest improvements.

If you’re just interested in videos/pictures, skip to the bottom.

Equipment

  • Nomad, with the back removed for easy access to the control box
    • Note: this means the Nomad was louder than it would be in normal operation, do not take the noise readings to be a good indication of the sound you’ll hear in normal operation
    • Another note: My Nomad has sound-insulating rubber on the bottom to stop vibrations into the surface it rests on, this may reduce noise relative to a stock Nomad
  • Arduino Uno, hooked up to Watterott’s TMC2209 SilentStepStick with a simple breadboard and some hookup wire.
  • For the stock Nomad controller, the original power supply provided by Carbide 3D
  • For the Arduino + TMC2209s, a MeanWell RSP-320-24 power supply.
    • Note: the RSP-320-24 has a fan built in, so you’ll hear wooshing in the background of the TMC2209 videos, resulting in a higher baseline noise level.
  • Pixel 4 XL for recording video
  • iPhone 11 with the Decibel X app for measuring noise levels

Setup

I set up the Nomad with:

  • Stock drivers
  • TMC2209 drivers in “StealthChop” mode (the one that’s meant to be silent)
  • TMC2209 drivers in “SpreadCycle” mode (the “normal” mode)

Method

  • I first homed the machine with the stock controller, then powered it down
  • For each run:
    • Turn on the machine but don’t home it, so that the following GCODE can run verbatim on both controllers (I didn’t connect the Arduino to the limit switches)
      G1 F100 Y-2.5 X-2.5
      G1 F200 Y-7.5 X-7.5
      G1 F400 Y-17.5 X-17.5
      G1 F800 Y-37.5 X-37.5
      G1 F1600 Y-77.5 X-77.5
      G1 F2600 Y-157.5 X-157.5
      G1 F2600 Y0 X0
      
      This GCODE was written to move the machine at a variety of feed rates, over a distance that results in the same amount of time for each line.
    • Switch on the iPhone’s noise level app
    • Turn on video
    • Run GCODE

Results

Summary

Setup Decibel X report Video
Stock Link Link
TMC2209 StealthChop Link Link
TMC2209 SpreadCycle Link Link

Graphs

Stock

stock

StealthChop

stealthchop

SpreadCycle

spreadcycle

Conclusion

The stock drivers are noisy as heck. If you look at the report, you’ll see that it peaks at 78dB (as loud as a truck) and if you look at the graph, the average noise level is around 70dB (as loud as a car) at all speeds.

At the lower feed rates, StealthChop and SpreadCycle are both essentially silent. StealthChop doesn’t even register above the ~44dB background noise until ~400 mm/min and it does so just barely. For the most part, StealthChop is around 60dB (conversation) but it does peak at around 70dB (car) when moving at 2600 mm/min.

SpreadCycle though does very well at higher speeds, peaking at a mere 60dB (conversation), a full 18dB quieter than the stock drivers.

If you combine StealthChop and SpreadCycle (which Trinamic recommends, automatically switching is built into most of their drivers), your steppers should be essentially silent below 400 mm/min and peak at 60dB when running at higher speeds.

Finally, it should be repeated that I’m running my machine with the back removed, so all the sounds go straight into the air. When running this normally, it’ll be even quieter.

TL;DR: The Trinamic drivers turn a machine that makes as much noise as a truck into a machine that makes as much noise as a conversation.

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