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Author Topic: How do match dimensions from Mach to Mill??  (Read 6236 times)

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Offline CWB449

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How do match dimensions from Mach to Mill??
« on: April 13, 2009, 06:21:49 PM »

Hi everyone,

I'm tryng to setup my Mach3 and everything is great except the deminsions. When I load the roadrunner file in Mach3 and send it to my mill it comes out about the size of a pencil lead. So to test this I loaded a 3" circle file and on the milling machine it comes out a 1/4" in size. What in the world am I doing wrong. I'm very new at this so please be kind ;D

C

Offline Hood

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Re: How do match dimensions from Mach to Mill??
« Reply #1 on: April 13, 2009, 07:15:54 PM »
You need to set your steps per unit correctly.
 What type motors, steppers or servos? If steppers what drives? if servos what count encoders?
Any gearing between motor and ballscrew?
What pitch is the ballscrew
Hood

Offline CWB449

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Re: How do match dimensions from Mach to Mill??
« Reply #2 on: April 13, 2009, 07:45:45 PM »
Thanks, Hood,

I'm using the Keling CNC 3 Axis Package with 425 oz-in motors with the KL-4030 Bipolar drivers with the 36V /8.8A Power Supply     

http://www.kelinginc.net/CNCNEMA23Package.html

On a Sherline 2000 Milling machine. Should pretty much straight forward.

I tried to tune the motors using the "Motor Tuning" Dialog box, but when I move the sliders nothing happens...I think this may be part of the problem, just don't know.

The setup I have is;
Mach3 w/ LazyCam
Keling Motors & drivers
Vista CNC Pendent w/ iMach Screen set

Thanks for your help,

C

Offline Hood

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Re: How do match dimensions from Mach to Mill??
« Reply #3 on: April 13, 2009, 07:48:18 PM »
Ok need to know the pitch of the screws, think it may be 10tpi but not sure, also what microstepping do you have the drives set to? and are the motors coupled direct or do you have reduction?
Hood

Offline CWB449

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Re: How do match dimensions from Mach to Mill??
« Reply #4 on: April 13, 2009, 10:10:39 PM »
Ok, threads are 20 tpi. Stepping 1/8, they are direct drive.

Motor Tuning;

Steps Per;  2000

Velocity;  120

Accel;    8

Step Pulse;  0

Everything seams to work good at this setting

Dir Pulse;  0

Offline Hood

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Re: How do match dimensions from Mach to Mill??
« Reply #5 on: April 14, 2009, 01:57:04 AM »
200 steps per motor rev, multiplt by 8 for micro stepping = 1600 steps per rev. 20 revs of screw to move 1 inch so thats 20 x 1600 = 32,000 steps per unit that you need.
Hood

Offline CWB449

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Re: How do match dimensions from Mach to Mill??
« Reply #6 on: April 14, 2009, 05:17:01 AM »
Thanks Hood,

 I'll give it a try. Does changing the steps change the speed of the motors?
I also noticed my sliders don't work in the Motor Tuning dialog box, "motors won't turn" to fine tune. On top of that "jog" doesn't either. Could my VistaCNC Pendent have anything to do with it?

Thanks for all your help,

Curtis

Offline Hood

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Re: How do match dimensions from Mach to Mill??
« Reply #7 on: April 14, 2009, 05:49:20 AM »
Vista can be a PITA to get working, I ahve never liked Vista so have never even attempted to try Mach on it. Check out the Vista part of the forum and you should find answers.
Hood

Offline Jeff_Birt

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Re: How do match dimensions from Mach to Mill??
« Reply #8 on: April 14, 2009, 09:31:14 AM »
Hood he said 'VistaCNC pendant' as in http://www.vistacnc.com/, NOT Windows Vista. :)

I have not used the pendant mentioned but have/do use Mach with Vista (and a SmoothStepper) no problems.
Happy machining , Jeff Birt
 

Offline zarzul

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Re: How do match dimensions from Mach to Mill??
« Reply #9 on: April 14, 2009, 02:40:22 PM »
Curtis,

Yes, it will affect the speed.   You will want to slow it down.  After the change it will try to go the 3" in the same time that is was moving the 1/4", or 32000/2000 = 16 times as fast.