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A axis setup problems
« on: May 04, 2013, 12:21:23 PM »
Hello everyone,

I have a K2CNC system and I recently added a 4th axis on my own.

I added a G201 Stepper Drive from Gecko drive and a SureStep stepper motor, single shaft, 276 oz-in holding torque, 2.8 amps/phase, 1.8 degrees / full step (200 steps/revolution), NEMA size 23, bipolar

I just setup my 4th axis and it works but now I get noise on my other 3 motors when they move it's almost a grinding noise.

I changed my Step Pulse to 5 from 0 and it got much better but still makes noise.

I created a new profile in Mach 3 for the rotary axis and if I use my old 3 axis profile the motors run quietly.

Any help would be appreciated.

Greg
"Ideas have consequence" Ravi Zaccharias
Re: A axis setup problems
« Reply #1 on: May 04, 2013, 12:29:02 PM »
Also I'm stumped on how to make the A axis display in degrees, I need to figure out how to make one revolution = 360 deg.

If anyone could help me in this area it would be greatly appreciated.

Greg
"Ideas have consequence" Ravi Zaccharias

Offline RICH

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Re: A axis setup problems
« Reply #2 on: May 04, 2013, 08:45:14 PM »
Quote
Also I'm stumped on how to make the A axis display in degrees, I need to figure out how to make one revolution = 360 deg.

There is info in the Mach Manual, but, if I recall correctly......
 
Under General Config> check the box .......A - axis is Angular

The steps per unit should be in degrees in motor tuning for the A axis.
Thus for a 72:1 gear reduction on the rotary and microstepping :
200 steps per one rev of motor X 10 micro steps x 72 gear reduction=144,000 steps per 360 degrees
144000/360 = 400 steps per degree

Play with the Velocity and Accel settings to find motor tuning settings.

RICH
« Last Edit: May 04, 2013, 08:47:26 PM by RICH »
Re: A axis setup problems
« Reply #3 on: May 05, 2013, 11:34:22 AM »
Excellent thank-you for the help.

Does anyone have any ideas about my first question about the motors?

I read on the forum that motor noise can often be mechanical but I know if I switch profiles and turn off the A axis no noise so I know its not mechanical but it could be electrical?

I used slightly different gauge wire then what was originally used on the rest of the machine wiring could that be it or a bad soldering job?

Just wondering it could be something very simple.
"Ideas have consequence" Ravi Zaccharias

Offline stirling

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Re: A axis setup problems
« Reply #4 on: May 05, 2013, 12:56:05 PM »
I have a K2CNC system
There are many... link?

Initial thoughts... power supply... enough amps?

I changed my Step Pulse to 5 from 0
Why?
Re: A axis setup problems
« Reply #5 on: May 06, 2013, 10:41:20 PM »
Quote
Link

K2CNC doesn't sell that machine any more so I have a link to their site through a web archive.

http://web.archive.org/web/20060117044013/http://www.k2cnc.com/CNC-router-KT-2514_detail.asp

I changed my Step Pulse to 5 from 0

Quote
Why?

I went digging on this forum for motor noise and I read some one recommend that or it may have been in the tutorial videos.

But the power supply that you mentioned may be correct. I will look into that more.
"Ideas have consequence" Ravi Zaccharias
Re: A axis setup problems
« Reply #6 on: May 08, 2013, 10:01:22 PM »
So if I don't want to use a gear ratio and want to use direct drive it would be 360 deg / 1.8 deg per step = 200?
"Ideas have consequence" Ravi Zaccharias

Offline Hood

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Re: A axis setup problems
« Reply #7 on: May 09, 2013, 03:17:20 AM »
Steps per unit for a rotary axis means steps per degree, so if you do not have any reduction it will be the steps of your motor multiplied by any microstepping you have then divided by 360.
Example would be 200 motor steps per rev  x 10 microsteps of stepper drive  = 2000  divide that by 360 = 5.5555555 steps per degree.
Hood

Offline RICH

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Re: A axis setup problems
« Reply #8 on: May 09, 2013, 05:40:42 AM »
Just a comment if no refuction is used. Resolution decreases thus actual positional accuracy suffers.
At 5.6 steps per degree the approx positional accuracy you could expect would be +- 649 seconds=11 minutes.
11 minutes=0.0033" @ 1"  distance &  0.013"@4"
A good way to visualize this would be to shoot at a target at 100 yards , thus you would be at +- 33 inches away from the bullseye.
A handy  angular to distance conversion  is 1 second = 0.001" at 17 feet.
May not be a concern for you.

RICH
Re: A axis setup problems
« Reply #9 on: May 10, 2013, 12:08:00 AM »
Thanks for your help guys I really appreciate it.

It was mentioned that it may be my power supply that could be causing the noise on my motors.

What I know so far:
My power supply is 23VDC 300VA
My stepper motor is 2.8 Amps, 3.8mH/phase.
My stepper drive can run between 18VDC and 80VDC.

There is resistors in my router and I'm not sure why they are there.
There are three:
35v 10000uF
63v 330uF
63v 10uF

Any ideas?

Regarding steps per unit how do I find out what my microstepping is?
I read the driver and motor manual I didn't see anything about microstepping.

Thanks again for you help.
"Ideas have consequence" Ravi Zaccharias