Machsupport Forum
Mach Discussion => Mach3 under Vista => Topic started by: Sonolink on October 04, 2018, 06:08:52 AM
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Hi
I'm new to this forum and I'm trying to use the STEPS PER UNIT CALCULATOR. I'm quite new to CNCing and I'm spanish so excuse my ignorance and eventual language barrier.
I have a chinese 3 axis 40x30 machine with a JK02-M5 Breakout board, 2M542 Stepper Motors, and a Dell Optiplex 745 dedicated computer.
The Balls screws on my machine are "1204"
I work in metric units.
My first question is: in the section "leadscrew" of the STEPS PER UNIT CALCULATOR would "pitch" be 12 or 04? Same for "lead".
My 2nd question is: do I have to fill the lower section of the calculator and if so, how? (feed, Stepper RPM, Pulse/sec, Distance vs Steps)
Thanks a lot for your help
Cheers
Sono
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Hi ,
I see the confusion.
'Pitch' is the distance between the crest of adjacent threads and 'Thread Starts' are the number of individual threads.
Basically the calculation provides the distance the carriage moves from one complete revolution of the screw and this is defined as the 'Lead'.
You do not have to complete the lower part of the calculator to obtain the Steps per Unit.
Once you have established the correct Steps per Unit they can be checked by using the Axis Calibration feature on the Settings page.
Tweakie.
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Thanks for your fast reply Tweakie
So if I understand it correctly, if my Ballscrew is 12mm diameter and 4mm Pitch and it has one start, Lead (mm/rev) value on the file should be 4, right?
Cheers
Sono
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So if I understand it correctly, if my Ballscrew is 12mm diameter and 4mm Pitch and it has one start, Lead (mm/rev) value on the file should be 4, right?
Correct ;)
Tweakie.
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Any recommendation or standard value, or any system to determine a good value for microsteps?
I want to use the machine mainly to cut PCBs...
Cheers
Sono
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8 :)
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8?
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Hi Sono,
The most common microstep setting is 8 (or 1/8th).
The Gecko website has some excellent explanatory tutorials; https://www.geckodrive.com/support/step-motor-basics.html
Tweakie.
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Oh I see. That would mean I should set the steppers' microswitches to 1600 microsteps and put the same value in Mach motor tuning, right?
Thanks
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Oh I see. That would mean I should set the steppers' microswitches to 1600 microsteps and put the same value in Mach motor tuning, right?
Thanks
No.
Set the microsteps to 8
Tweakie.
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Tweakie,
On the stepper driver the lowest value I can set the microswitches for microstepping is 400....
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Or do you mean I should put the microswitches on the stepper to 1600 (200x8) and put "8" in Mach3 Motor tuning?
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Or do you mean I should put the microswitches on the stepper to 1600 (200x8) and put "8" in Mach3 Motor tuning?
That is it exactly (sorry for my bad explanation).
Tweakie.
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No probs Tweakie!!
Thanks for your help, I'll try it this afternoon ;)
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One last thing please:
My PSU is 36V/10A. My motors are rated 3A/425oz and the steppers drivers' are set to 2.84A. One of the microswitches can be set to "Maintain full current in the stop state" or "Automatically reduce current in the stop state". Which position is more adequate to help preventing missing steps, or it just doesn't matter?
Thanks
Cheers
Sono
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Ok, so I've
-set the stepper drives' to 1600
-in Mach3 "Motor Tuning" menu, in "Steps per" I put "8" as value
Result: the machines moves to wrong distances.
So I went to "Settings" and let Mach3 calculate "Steps per" and the number it came up with was 400. With this value the machine would measure spot on.
I tried changing the stepper microswitch to 3200 and Mach3 came up with 800 (oh surprise!).
I put the microswitches back to 1600 and 400 in Mach3 and tweaked Velocity and Acceleration a bit.
Final settings in Mach3 are:
"steps per": 400
Velocity: 1500
Acceleration: 200
Now the machine moves like this when activated through the keyboard and after a Feed Rate command of F900:
https://youtu.be/EmLgoyCIOMs
Does that look/sound ok? Any suggestions for improvement?
Thanks :)
Sono
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If it's of any use I tried a few "Verify" commands after several movements on all axis and it always comes up with results in this range:
X= -0.0900
Y= -0.0025
Z= -0.0281
Cheers
Sono
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Ok so your 400 steps per is correct (MotorFullStepsPerRev / ScrewPitch) * Microstep gives (200 / 4) * 8 = 50 * 8 = 400 :)
Explain your "verify" commands, please.
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Explain your "verify" commands, please.
I just move the machine around using the 3 axis. Then I click on "Verify" in Mach3. Mach3 homes the machine and returns to the position it was and shows those numbers. Hope that explains :)
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Hi Sonolink,
Reduce current in stop state is the usual and recommended setting for stepper drivers.
Your machine looks good and from the very short video sounds good too.
I do not know the purpose of the Verify Position command or what the displayed indication represents.
Tweakie.
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Ok, thanks guys.
I will begin some testing today to check repeatability. I hope it doesn't miss any steps.
I'll keep you guys posted.
Thanks again for your time and help :)
Cheers
Sono
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https://youtu.be/AeoWV69hve0
https://youtu.be/CSAAzrCLL70
(https://imagizer.imageshack.com/v2/150x100q90/924/9P2Mn8.jpg) (http://imageshack.com/f/po9P2Mn8j)
Not too shabby for a first one :)
Very pleased with the machine so far.
Thanks a lot for your help again.
Cheers
Sono
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Hi,
nice effort with that board.
If you haven't already seen it have a look at Autoleveller, I have found it to a boon to PCB making.
http://www.autoleveller.co.uk/ (http://www.autoleveller.co.uk/)
Craig
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Thanks for the link Craig, I'll check it out
Cheers
Sono
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Excellent work Sonolink.
Tweakie.
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Thanks Tweakie! Still in the long learning process but quite pleased so far ;)