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You can turn them by hand when powered up? How about your steps per unit within Mach3? Where are the dip switches set on the driver?
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Oh, sorry, they actually take about 3 seconds to make 1 rpm.Originally Posted by Fastest1
I can turn the shafts by hand, they make a vibrating clicking noise when this is done, but its not hard.
Velocity is set at 120 IMP
You can turn them by hand when powered up? How about your steps per unit within Mach3? Where are the dip switches set on the driver?
Yes, but its fairly hard. I just changed the "Steps Per" to 4000 instead of 2000. They seem to have doubled in speed. What is ideal for a standard 1.8 degree motor? I think it defaulted at 2000.
200 steps at 1.8 degree. However to minimize resonance microstepping is used. leadscrew pitch is also a factor. You need to use the axis calibration tool
Axis calibration tool? Alright, Ill look for that. Also, the Y axis motor is vibrating much more than the X axis motor when running. Enough for it to vibrate across the table. Both are tuned in the same way in the Motor Tuning tab. Any ideas? Could one be set to lock as you mentioned before? If so, where would I be able to check this?
Edit: My ballscrews are .2"/turn. Ive heard Hoss say he sets his microstepping at 1/2. Puzzling when I hear that the G540 is set at 10X microstepping. Is this 20 times the microstepping or am I missing something?
I have settings for "Pulse per rev" on my drivers, should these be set in any particular way? Is this the same as microstepping?
You have to have mach 3 and the driver set up the same in regard to microstepping or the speed will not match. If for example you have the driver set for 25,000 steps per revolution, but have mach 3 set for 400 steps per rev, your motor will turn 400/25000 or 1/63rd as fast as it should.
As 109 is saying, there are a few factors. To be more specific the stepper you mentioned (1.8 degree) is how far the stepper actually moves in 1 pulse. Since it is 1.8 degree x 200 steps to equal 360 degrees or a full revolution. Then pitches and or gears and pulley ratios get added on too.
Sorry I was eating dinner. Your screws at .2 per turn means 5 turns per inch. So 200 steps per revolution x 5 tpi x whatever microstepping value (a g540 is only 10x and is not variable) your digital driver can be almost anything but try 1/2 at Hoss' recommendation this would be 200 x 5 x 2 = 2000 steps per inch. this will have to match as 109 mentioned in both Mach and on the drivers dip switches. More on axis calibration later.
Ah I see. I have them both set to 10000 pulse/rev. The motors rotate smoothly and much faster than before. I guess now I need to find a box to mount this mess in and install it on the mill. Thank you so much for your help!
Edit: Thanks Fastest1, some great info you're throwing my way. I'll try 2000 steps/rev and see how it goes. That y axis motor was vibrating much more than the others, but smoothed out at 10000 steps/rev. I'll play with it a bit more. Thanks again!
Is there anything different about the Y axis? Is it using the same pitch leadcrew/ballscrew? Are the gibs too tight? The steps per unit calculation is a mathematical formula. It will vary a small amount due to error in the screws etc. Also this will tell you the resolution (if 2000 steps per unit is required, then the smallest move could only be 1/2000th of a unit (inch in this case) or .0005" theoretically. Unless you are running a belt drive to your screws from your stepper you will most likely be in the 2000 steps per unit range with 1/2 stepping. regarding the axis calibration, on the "settings" page within Mach 3, just above the red reset button there is a button that says "Axis calibration, Set steps per unit". Upon pressing this, you will be prompted on which axis you would like to calibrate. Then you will be asked how far you want the axis to move. You will need a method of measuring its movement accurately. However before setting up any measuring devices, see if you are in the ballpark. Ask it to move 1", if it does move what appears to be 1" great, repeat and measure. Most likely it will be off. It is actually good to go back thru this a few times on each axis as your steps per unit settings get more precise. You also want to do this as your machine is used over the year/month/week to verify your settings are correct and accurate. They will vary a little bit over time.
Neither motor is mounted to the machine. The motor I have labled as Y is running very rough but seems much smoother now that I have the microstepping set to 10000. Is it bad to have it set so high?
And about that "1/2 microstepping", how can it be set at 1/2? The lowest I can set the driver to is 400 pulse/rev. Im sure im just not understanding something here.
And about the calibration: Ive seen Hoss's vid and think I will be able to get it done when I get a test indicator, which is still on my wish list.
A full step on a typical stepper motor is 1.8 degrees or 200 steps per revolution. So, 1 step = 1.8 degrees. 1/2 step would therefore be 0.9 degrees and there would be 400 of these half steps per revolution. I don't think you need more than about 1/10 microstepping (10 microsteps per full step) or 2000 steps per revolution on a typical milling machine application. If you use a 0.2" lead ballscrew that means each revolution is 0.2" and each for those 2000 microsteps would be 0.0001". Most machines can't hold this tolerance anyway and setting it that high would only be for smoothness.If you use a stock acme leadscrew with 0.1" per rev, then 2000 microsteps per revolution means each step is 0.00005". I have tried mine out on my mill drill at 1/16 microstepping (3200 microsteps per revolution), 1/8 (1600 microsteps per revolution), and 1/2 (400 microsteps per revolution. I'm going to be running mine at 1/8 as I don't see a significant change in smoothness, but I do see a significant change in max speed that my computer/bob/driver arrangement can deliver reliably to the motor.
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