I have a modified ACRO I am using as a drawbot and the steppers give off a fairly steady high pitched noise that is just loud enough to become a nuisance over the course of plotting a file (which takes several hours). I'm thinking about approaches to drop the volume a bit so looking for suggestions (beyond closing the door and wearing hearing protection) from anyone here. Thanks
Odd. Maybe a current setting, or just a really resonant frame. I'd probably run Trinamics for a sound-sensitive project, but the BB should do ok. @Peter Van Der Walt?
Turn current down yes. For an Acro, all the way counterclickwise is perfect. The acrylic plates also do resonate a little. Of course no mechical system will ever be 100% noise less. Do keep that in mind. Even famed Tmc drivers are "quiet" (relatively, truth they still make noise) because it makes compromises in the decay cycle that leads to lower torque.
And aluminum is specifically an extremely resonant material. We're basically making machine frames out of tuning forks, but it's also cheap, light, rigid and strong, so compromises have to be made. Agree on the TMC downsides, I should probably have made it clear I meant specifically for this type of project- NEMA 17, very-low force, moderate speed. If you need a starting point, I'd set the current to 0.8A, and then only turn it up to 1.0 or 1.2A (and no higher) if the machine were having acceleration issues. If a NEMA 17 can't move quickly at 24V, 1.2A, you have other problems.
BlackBox has a minimum of about 1.3A, all the way counterclockwise The motors shipping with Acros are 1.7A
From the look of the spec sheet on the Part Store (Acro kit NEMA 17 motor image links to NEMA 23s, btw) they're very similar to the (2A, 3mH) ones I run quietly (as best the "TB6600s" can do so ) from StepperOnline at the above parameters. I think I have them turned up to 1.2A to get my 15,000mm/s accelerations, but that's all they've ever needed on the laser. Whatever works, though.
Yeah, I think it is resonating through one of the v-slot rails. I have the X-axis stepper mounted directly to the rail and it moves the gantry with a looped timing belt (instead of being mounted on the gantry.) I'll try inserting some type of rubber washer or maybe even wood between the X-axis stepper and the rail.
I ordered a set of 'Nema17 Stepper Motor Steel and Rubber Vibration Dampers' which I hope to test out next week. Since the offending sound is high frequency I am hoping these will keep the noise from propagating into the v-slot rail (aka tuning fork). Will post updates, and maybe even pictures but not making any promises...
Update >> much success from mounting the Stepper Motor to the Rubber Vibration Damper, which was then mounted to a 5mm thick piece of hardwood plywood mounted to the V-Slot rail. The high pitched ringing is completely gone, and I can only tell that the gantry is moving by looking at it . Here is a photo, the Y-axis stepper is the one that is acoustically isolated from the V-slot rail, and it drives a timing belt that moves the gantry up and down the Y-axis (the gantry is not in the picture). There is a bit of flex to the stepper mount, mostly from the Rubber Vibration Damper. If that develops into an issue then I'll replace it with a 1cm plywood plank.
jsyk, mounting the stepper to just a plank of wood does not noticeably dampen the sound. Can confirm that the rubber vibration dampers are doing most or all of that.
