Microstep problem

[Jussi_2]

Hi!
I have a weird problem with my CNC machine. When I move my machine with keyboard arrows, it will move very smoothly and nice to all directions. in all 3 at same time also.. Also if I CNC mill with direction of X or Y or Z with G-codes it works nice. but problem comes when it goes X+Y in same time. X+Z or Y+Z dosent cause problems. This causing very weird and terrible sound, and huge vibration. maybe something with microsteps.. i don't know.. The vibration makes my whole cnc machine frame shaking. Its bit hard to explain, maybe the video will show the problem better.

Here u can hear the problem:






Without G-code it is so soft movement:



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[IN-WondeR]

Do you have some EM interferrence. It sounds like when you run the motors together they interfere with each other. Are your motor cables shielded, and if so how are your shields grounded??

[Jussi_2]

Do you have some EM interferrence. It sounds like when you run the motors together they interfere with each other. Are your motor cables shielded, and if so how are your shields grounded??

Hi! Thanx for quick reply! I am using this shielded cable:
damencnc.com - Cable Assemblies
I didn't ground the shield. Maybe i try that. Its just so weird that it works so smooth and nice with keyboard, but the g-code will do this. Maybe because with arrow keys i can go only straight, or 45degree. With g-code it can go different angle. The sound is just so high, and shaking frame, that i afraid to mill.. This can't be normal, right? Maybe i try also lower ampers for motors. Drivers are set for 2000 puls/rev.

[ger21]

Sounds like you're getting resonance. That's a big frame, and looks to be very susceptible to vibrations.

[Jussi_2]

Sounds like you're getting resonance. That's a big frame, and looks to be very susceptible to vibrations.

I agree that the frame is big, and it can cause some vibration if the machine wont work normally. it make that sound even there is no vibration in some areas. the sound comes from motors, not from frame, but ofcourse when it start to more vibrate, it will get the frame to give some resonance sound.

What is difference between CNC machine moving with keyboard arrows manually pressed, and between that the G-code will move the machine? With arrow keys, I can't do that sound even I try many different movements. But the G-code will do that always when 45degree movement (X+Y).. But, if the machine moves X+Z or X+Y in same time, there is no sound. nice smooth movement. only X+Y causing this. I am soon thinking to buy a new drivers and test with them, but if it not solve this problem, then its just waste of money.. So I should test all other settings first. I can post some photos of my settings here.





I have 2000 pulse/rev from driver. I tried with 400, but the machine didn't work. Also I have sherline 1/2 mode on, as without it the machine didn't work. Kernel speed is 45khz.
I will today try the shield cable grounding, also check all other groundings again. I have 1600oz stepper motors. I put currently 3.5A RMS. Maybe I try to change it to 3.5A peak. Can someone bit comment these settings. thanx.

[Jussi_2]

This is how smooth it cut with G-code when there is no X+Y in same time.

[ger21]

Try turning off the toolpath and running your g-code. Also, check the CPU usage when it's making the noise.

The fact that you need to run in Sherline Mode tells me that your PC is not good for Mach3.
Also, using smaller motors will usually be much smoother. Those 1600 oz motors are far bigger than you need, and would be easily outperformed by motors half their sizer.

[Jussi_2]

Try turning off the toolpath and running your g-code. Also, check the CPU usage when it's making the noise.

The fact that you need to run in Sherline Mode tells me that your PC is not good for Mach3.
Also, using smaller motors will usually be much smoother. Those 1600 oz motors are far bigger than you need, and would be easily outperformed by motors half their sizer.

Ok, I will try this. Yesterday I grounded the shielded cable, and nothing changed. maybe with 10.000 pulse/rev it was bit smoother than with 2000...
Damn, where i get a third computer now haha.. First my laptop didn't work at all. Then I bought this pc, and if it turns to be bad now also.. I will cnc mill a RC powerboat hull today lets see how the machine do it.

[Jussi_2]

Why this red box?


Settings:

[Jussi_2]

Does this 47935 pulse frequency means that i should use 45khz kernelspeed? not 25.0000? I must try another computer....

[Jussi_2]

I bought gecko g540.. lets see if this solves my problems