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Author Topic: Running at Half Scale  (Read 4192 times)

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Running at Half Scale
« on: January 26, 2008, 06:57:57 PM »
I've set up everything to spec, I think, But I seem to be running at half scale.
My numbers in mach are correct, but my router is running at what it appears about half scale. What am I doing wrong?

Online Hood

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Re: Running at Half Scale
« Reply #1 on: January 26, 2008, 07:05:43 PM »
Make sure you have the scale set to 1 for each axis, you will see it at the right of each of the axis DRO's on the main page. If this is already set to 1 then are you sure you have the numbers right in your motor tuning? if its steppers you have they may be 0.9 degre steppers rather than the usual 1.8 degrees.
Hood
Re: Running at Half Scale
« Reply #2 on: January 27, 2008, 08:50:01 AM »
I've double checked everything and the motors and drives are set correctly.2000 steps, 1.8 degree motors. I bought everything as a package from
Automation Direct, so I know everything should work together. The scale is set at 1 on the DRO's. When I manual input values, say as inputting 1 inch I'll get only about .200 so I'm about 1/5th what I should be at. My lead screws are 5 TPI. I can set my drives up to 10000 steps. I reset my drives for 1000 step and I still get a reading of 1/5 of what I should have.
« Last Edit: January 27, 2008, 08:58:09 AM by tz1238 »

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Re: Running at Half Scale
« Reply #3 on: January 27, 2008, 09:29:21 AM »
can you give a link to the drives you have?

Hood

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Re: Running at Half Scale
« Reply #5 on: January 27, 2008, 09:44:11 AM »
OK so do you have them set up for 1/5 microstepping?
If yes then you need to set the steps per unit in Mach to 5000, this is because to move 1 inch you need 5 Revs of the motor, you have to send 200 steps to do one Rev when on Full stepping but five times that for 1/5 stepping so thats 1000 steps per rev. It then follows that you need 5Revs x 1000steps = 5000 steps per inch. Or at least I think it is, I am used to working in mm :)

Hood
Re: Running at Half Scale
« Reply #6 on: January 27, 2008, 10:04:31 AM »
I'll give it a try. I actually have them at 1/10, so if I keep that setting the motors would be at 10,000 steps?

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Re: Running at Half Scale
« Reply #7 on: January 27, 2008, 10:10:28 AM »
yes thats right 5 turns x 200 steps x 10 (for 1/10 micro) = 10,000 steps to move 1 inch. This is all presuming you have direct coupling of the motors to the screws.
Hood
Re: Running at Half Scale
« Reply #8 on: January 27, 2008, 10:32:16 AM »
Great, I'll give it a try and let you know how it worked out. Thanks for all your help.
Re: Running at Half Scale
« Reply #9 on: January 28, 2008, 05:01:49 PM »
Reset my motors and everything is right on the money. Thanks for all your help.