Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: kolias on January 28, 2017, 11:31:24 AM
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I got a new G540 and using the .XML from Gecko (540BVFD) the steps per setting is 20000 which makes my motor running very rough. Using the Mach3 “Set Steps per unit” on the Settings tab it gives me a steps per of 4002 which is pretty close to what I get with my calculations assuming a 1/8 microstepping. (my cals: 200 x 8 x 2.54 = 4064 with 10mm Lead ball screws)
What microsteps the G540 is using and can I change them?
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Hi,
what are you using as native units? Found on the Config/Select Native Units menu, set them once and then leave them alone. You can
use the alternate units for your Gcode jobs but DONT use this setting to achieve it, use codes G20/G21 instead.
If in mm which is a natural choice if using metric ballscrews the steps per unit would be:
200 full steps/rev times 8 microsteps per fullstep equals an axis movement of 10mm
ie 160 steps/mm.
If in inches:
200 full steps/rev times 8 microsteps per full step equals 0.3937 inch per rev
ie 4064.008 steps/inch.
Craig
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I got a new G540 and using the .XML from Gecko (540BVFD) the steps per setting is 20000 which makes my motor running very rough. Using the Mach3 “Set Steps per unit” on the Settings tab it gives me a steps per of 4002 which is pretty close to what I get with my calculations assuming a 1/8 microstepping. (my cals: 200 x 8 x 2.54 = 4064 with 10mm Lead ball screws)
What microsteps the G540 is using and can I change them?
The G540 is a 10uStep drive. You cannot change that. If you have a 100 pitch leadscrew then the steps/unit (mm as that's what your lead screw is) the calculations are;
200steps/rev * 10ustep = 2000 steps for 1 rev of the motor.
since 1 rev of the motor moves the axis 10mm then we get 2000/10 = 200 steps per mm
If you want to set your native units to imperial, then multiply the 200 * 25.4 = 5080 steps/inch.
Cheers,
Peter
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Thanks guys for the answers and BTW I use inches despite that my ballscrews are metric.
I wonder why Gecko uses 20000 since not all users will have a 10mm pitch ballscrews and although I do have 10mm ballscrews I have to use 4064 as Steps per
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4064 is incorrect.
If you have a 10mm pitch leadscrew then with a G5640 the steps/inch is 5080.
The G540 is a 10ustep drive. It is NOT an 8ustep drive.
Peter
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My mistake Peter, 5080 is correct
Thanks
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I wonder why Gecko uses 20000 since not all users will have a 10mm pitch ballscrews
When there are an infinite number of possibilities, what are they supposed to use?
The .xml 's purpose is mainly to configure the inputs and outputs correctly.
There are numerous settings in an .xml file that are very different from machine to machine, even when the machines are the same.
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I understand Gerry, thanks however perhaps Gecko should have put a note somewhere stating the 20000 may not be applicable to all users. I spent more than a day trying to configure my 4 motors to run smooth because I thought if Gecko says to use 20000 they must be right
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I understand Gerry, thanks however perhaps Gecko should have put a note somewhere stating the 20000 may not be applicable to all users. I spent more than a day trying to configure my 4 motors to run smooth because I thought if Gecko says to use 20000 they must be right
I'm a bit surprised that you are apportioning blame to Gecko.
The steps per unit value is dependent on the following;
- Micro steps of the stepper drive,
- Steps per revolution of the motor
- Pitch of the lead screw
- Mechanical gearing in the drive train for an axis.
Out of the five variables above, Gecko is responsible for one of them.
If you had read the manual http://www.machsupport.com/wp-content/uploads/2013/02/Mach3Mill_1.84.pdf specifically section 5.5 Tuning Motors you would understand that Gecko would never suggest a value for your machine. It would be clear that the XML profile provided by Gecko sets up the input and output pins for their G540 drive.
They cannot know the steps/per value, or the velocity and acceleration values for your machine or any other machine.
Every Mach3 profile has to have a value in the steps per field. The ones in the profile from Gecko are most probably the values they use for the machine that they created the profile.
As a suggestion, read the manual cover to cover. You may not understand it all but enough will sink in so that it should jog your memory when you have questions.
Cheers,
Peter
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....... It would be clear that the XML profile provided by Gecko sets up the input and output pins for their G540 drive.
They cannot know the steps/per value, or the velocity and acceleration values for your machine or any other machine.
Cheers,
Peter
I understand what you are saying Peter and for the fairness of all I still say that Gecko should have put a note somewhere in their Manual to say that in their XML the “Steps per” is only just a number and the user should establish their own value.
Let’s say I’m a guy who uses his mill for x number of years and one day I decide to use the G540 and since they provide an XML I say well Gecko is a big name might as well use their XML. I see the 20000 in their XML and I say well this number does not make any sense but since it’s provided by Gecko they must know something I don’t know or this number is something special for the G540. This scenario can happen to anyone
Another mistake on the same XML under Ports & Pins / Motor Outputs, Spindle line, the Step Port is 0. That should be 1 otherwise no PWM signal is generated (BTW I found this from another forum and it works for me)
I value the Gecko products and your knowledge Peter but that’s the way I see it and this post is not intended to blame anyone rather to state my experience and perhaps help someone.
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My opinion is that users should never use an .xml supplied by a 3rd party, unless the .xml is supplied with a turn key machine.
As you've seen, some settings will always be incorrect, and not just steps/unit.
Learning how your machine works, and how to configure Mach3 for your machine, doesn't take long, and is very beneficial when problems arise.
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Sound advise Gerry but beginners, newcomers and the inexperienced, etc. would perhaps use (and trust) a Gecko provided .xml.
The Gecko documentation does not make it absolutely clear that Steps per Unit need to be altered according to the machine nor do they make it clear that the G540 has fixed 1/10th microstepping (which is essential information for calculating the steps per for any machine).
The Gecko products and documentation are second to none but improvements could be made to the documentation as Kolas has pointed out.
Tweakie.