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Hello, I am building a 1500mm x 1000mm laser cutter and am having some problems with excessive noise/ vibration during slower moves. I have tried different micro stepping configurations but this doesn't seem to help. The longer Y axis with two motors has much more noise than the X.
Any suggestions?

I have attached 3 videos.
Y moving slowly and making lots of vibration
Y moving fast and sounding much better
X moving slowly and sounding alright

 

Thanks for the input. I have tension nuts and thrust bearings for the screws. My couplers are slipping when I put sufficient tension on the screws. This is another issue that I'm currently working on.

I'll think about your second point. I have experimented with the gantry being misaligned and this does not cause the laser to miss the final optic. The mirror on the gantry is fixed to the gantry so it would rotate along with the gantry beam if twisted.

I will be enclosing the laser after the mechanical issues are sorted out.

 

The problem isn't the motor torque. The screw is pulled linearly out of the motor coupler when I pre tension the screw.

I will heed your advice. Thank you for bringing it up. I haven't had any issues at all with my leadscrew converted router table but I see where it could be a bit more of an issue here. Perhaps I could use a low power laser emitter and detector which when no longer aligned, triggers an emergency stop.

 

I' have etched and blued steel sheet down to prevent penetration to the wood table. I'll have adjustable height holders of a wire mesh for work holding.
I have a 3.5" fume extraction system that I'll use directly on the cutter head until it's enclosed. I'm printing a hose holder and intake plenum over the night.

 

I'm using these nuts: Tension Nut - OpenBuilds Part Store
these bearings: Thrust Bearing - OpenBuilds Part Store

The problem is the clamping force of the motor coupler.

 

It is not. I did just realize one of my problems though. I only have a tension nut on one side of each screw. The other side has been held in tension by the motor coupler but I think it will be better for the coupler to only be handling the rotational force.

 

Thanks for the reply. I don't have the materials to enclose the whole laser yet but have some steel tube to enclose the path of the beam for two of the travels. I had two tension nuts and thrust bearings off of my router at home so I'll see if the screw under tension can handle the higher speed with more tension.

 

I may look into belts but this laser is mostly for cutting 12mm EVA foam and needs a pretty slow cut speed.

 

That's something I'll definitely consider as an upgrade. I'd like to get it working first and improve one thing at a time.

 

I tightened the screws by putting tension nuts and thrust bearings on the motor side. I also 3D printed motor mounts to allow coupling the motors.The whipping looks a lot better and the sound is actually a bit better but still way louder than it should be.

This is making me more certain that the problem is the motor drivers like previously suggested. They are "Microstepping" but still a lot of cogging and resonance is still occurring.

 

These are the drivers that I am using:
CNC Digital Microstep driver DM542 Stepper Motor Controller 2-phase Digital Stepper Motor Driver 20-50V DC Max 4.2A for Nema 17, Nema 23 and Nema 34 series stepper motor, Replace M542 M542H - - Amazon.com

I've adjusted the current and microstepping to see if anything helped the noise and it didn't.
Amperage is currently at 2.84a and microstepping at X8 (1600)

Also, when I drive the screws with a drill, they sound smooth.

 

3 x 23HS8430B stepper motor 76mm 270oz-in dual shaft
SainSmart GRBL usb controller: SainSmart 3-Axis GRBL USB Driver Controller Board DIY Engraver Control Board for GRBL - - Amazon.com
Raspberry pi 4b running UGS

GRBL Settings:

"key": "$10", "value": "3", "units": "mask",
"description": "Alters data included in status reports.",
"shortDescription": "Status report options"

"key": "$11", "value": "0.010", "units": "millimeters",
"description": "Sets how fast Grbl travels through consecutive motions. Lower value slows it down.",
"shortDescription": "Junction deviation"

"key": "$12", "value": "0.002", "units": "millimeters",
"description": "Sets the G2 and G3 arc tracing accuracy based on radial error. Beware: A very small value may effect performance.",
"shortDescription": "Arc tolerance"

"key": "$13", "value": "0", "units": "boolean",
"description": "Enables inch units when returning any position and rate value that is not a settings value.",
"shortDescription": "Report in inches"

"key": "$0", "value": "10", "units": "microseconds",
"description": "Sets time length per step. Minimum 3usec.",
"shortDescription": "Step pulse time"

"key": "$1", "value": "25", "units": "milliseconds",
"description": "Sets a short hold delay when stopping to let dynamics settle before disabling steppers. Value 255 keeps motors enabled with no delay.",
"shortDescription": "Step idle delay"

"key": "$2", "value": "0", "units": "mask",
"description": "Inverts the step signal. Set axis bit to invert (00000ZYX).",
"shortDescription": "Step pulse invert"

"key": "$3", "value": "0",
"units": "mask", "description": "Inverts the direction signal. Set axis bit to invert (00000ZYX).",
"shortDescription": "Step direction invert"

"key": "$4", "value": "0", "units": "boolean",
"description": "Inverts the stepper driver enable pin signal.",
"shortDescription": "Invert step enable pin"

"key": "$5", "value": "0", "units": "boolean",
"description": "Inverts the all of the limit input pins.",
"shortDescription": "Invert limit pins"

"key": "$6", "value": "0", "units": "boolean",
"description": "Inverts the probe input pin signal.",
"shortDescription": "Invert probe pin"

"key": "$120", "value": "500", "units": "mm/sec^2",
"description": "X-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.",
"shortDescription": "X-axis acceleration"

"key": "$100", "value": "200.000", "units": "step/mm",
"description": "X-axis travel resolution in steps per millimeter.",
"shortDescription": "X-axis travel resolution"

"key": "$122", "value": "10.000", "units": "mm/sec^2",
"description": "Z-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.",
"shortDescription": "Z-axis acceleration"

"key": "$121", "value": "250", "units": "mm/sec^2",
"description": "Y-axis acceleration. Used for motion planning to not exceed motor torque and lose steps.",
"shortDescription": "Y-axis acceleration"

"key": "$102", "value": "80.000", "units": "step/mm",
"description": "Z-axis travel resolution in steps per millimeter.",
"shortDescription": "Z-axis travel resolution"

"key": "$101", "value": "200.000", "units": "step/mm",
"description": "Y-axis travel resolution in steps per millimeter.",
"shortDescription": "Y-axis travel resolution"

"key": "$20", "value": "0", "units": "boolean",
"description": "Enables soft limits checks within machine travel and sets alarm when exceeded. Requires homing.",
"shortDescription": "Soft limits enable"

"key": "$21", "value": "1", "units": "boolean",
"description": "Enables hard limits. Immediately halts motion and throws an alarm when switch is triggered.",
"shortDescription": "Hard limits enable"

"key": "$22", "value": "1", "units": "boolean",
"description": "Enables homing cycle. Requires limit switches on all axes.",
"shortDescription": "Homing cycle enable"

"key": "$23", "value": "0", "units": "mask",
"description": "Homing searches for a switch in the positive direction. Set axis bit (00000ZYX) to search in negative direction.",
"shortDescription": "Homing direction invert"

"key": "$24", "value": "100.000", "units": "mm/min",
"description": "Feed rate to slowly engage limit switch to determine its location accurately.",
"shortDescription": "Homing locate feed rate"

"key": "$25", "value": "2000.000", "units": "mm/min",
"description": "Seek rate to quickly find the limit switch before the slower locating phase.",
"shortDescription": "Homing search seek rate"

"key": "$26", "value": "250", "units": "milliseconds",
"description": "Sets a short delay between phases of homing cycle to let a switch debounce.",
"shortDescription": "Homing switch debounce delay"

"key": "$27", "value": "3.000", "units": "millimeters",
"description": "Retract distance after triggering switch to disengage it. Homing will fail if switch isn\u0027t cleared.",
"shortDescription": "Homing switch pull-off distance"

"key": "$131", "value": "15000.000", "units": "millimeters",
"description": "Maximum Y-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.",
"shortDescription": "Y-axis maximum travel"

"key": "$130", "value": "1000.000", "units": "millimeters",
"description": "Maximum X-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.",
"shortDescription": "X-axis maximum travel"

"key": "$111", "value": "2200", "units": "mm/min",
"description": "Y-axis maximum rate. Used as G0 rapid rate.",
"shortDescription": "Y-axis maximum rate"

"key": "$110", "value": "8000", "units": "mm/min",
"description": "X-axis maximum rate. Used as G0 rapid rate.",
"shortDescription": "X-axis maximum rate"

"key": "$132", "value": "200.000", "units": "millimeters",
"description": "Maximum Z-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances.",
"shortDescription": "Z-axis maximum travel"

"key": "$112", "value": "200.000", "units": "mm/min",
"description": "Z-axis maximum rate. Used as G0 rapid rate.",
"shortDescription": "Z-axis maximum rate"

 

Adjusting pulse lengths didn't seem to change anything.

 

Yes, they move fine by hand.