Hello Guest it is December 14, 2019, 01:19:01 PM

Author Topic: Steps Per seem wrong, Halp Plz  (Read 1824 times)

0 Members and 1 Guest are viewing this topic.

Steps Per seem wrong, Halp Plz
« on: October 06, 2015, 05:32:53 AM »
Hello, Im new to CNC but built one as a project, it have it up and running and it works great.

My only real problem is the motor tuning, im using 200 pulse 1.8 nema 23 motors, Gt3 belts and 20 tooth pulleys on X and Y and 2m pitch 8mm leadscrew on Z direct drive, I have my micro steppers set to 1600. My problem is that I need to set the steps per in motor tuning to as low as 13.5 to get it to move the correct distance on X and Y and set to 100 on Z, I have tried using the manual calcs, using the xcell doc, these did not work, I then just taped some steel rules to the X and Y axis and slowly tuned them to move right, I got them spot on and was cutting things perfect to scale with the readouts matching movement. These settings however seem extremely low compared to every thing I have read. So I then discovered the inbuilt cal tool in Mach3, so I ran this and it gave me the exact same as what I had 13.5 for X/Z and 100 for Z.

No matter what I do these are the only settings that work.
In addition, it does not matter what microsteps I set on the micro steppers it does not change anything.

Can anybody help me please, im lost as to what the problem could be, maybe the microsteppers are no good?
Re: Steps Per seem wrong, Halp Plz
« Reply #1 on: October 06, 2015, 06:33:24 AM »

Offline Tweakie.CNC

*
  • *
  •  8,022 8,022
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Steps Per seem wrong, Halp Plz
« Reply #2 on: October 06, 2015, 07:02:02 AM »
Hi Rocky,

Direct drive belt systems usually have a small number of steps per unit - that is just the way it is.

Please excuse me for not understanding but if your machine is working OK then what is the problem that you are having ??

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Steps Per seem wrong, Halp Plz
« Reply #3 on: October 06, 2015, 10:51:14 AM »
Thanks Tweakie

Not really a problem, just that the breakout board needs to be set with the steps as well to get the led display to show coords, it can only be set in multiples of ten so I cant get it to match the coords of Mach three. Its not really a problem.

Main think I was interested in is weather I had done something wrong as all i've read people have way higher steps than me running similar setups.

I am curious as to why if I change the settings on the microstep drivers it makes no difference to the amount of movement?

Offline Tweakie.CNC

*
  • *
  •  8,022 8,022
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Steps Per seem wrong, Halp Plz
« Reply #4 on: October 07, 2015, 02:37:10 AM »
Quote
I am curious as to why if I change the settings on the microstep drivers it makes no difference to the amount of movement?

I think you have a problem there somewhere - changing the driver's microstep settings should make a difference to the distance the machine axis travels but you may be seeing some compatibility issues with that breakout board.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Steps Per seem wrong, Halp Plz
« Reply #5 on: October 07, 2015, 02:54:58 AM »
Quote
I am curious as to why if I change the settings on the microstep drivers it makes no difference to the amount of movement?

I think you have a problem there somewhere - changing the driver's microstep settings should make a difference to the distance the machine axis travels but you may be seeing some compatibility issues with that breakout board.

Tweakie.

So I chanced the micro-stepper settings last night and it didn't seem to make a difference, however on reboot today I had to re tune the motors by doubling the steps, I suspect this was because of the Drivers.

Is it possible they have a memory and need to be powered of for awhile before the settings will take effect? Sounds unlikely but im very new t this stuff.

I played with the settings again and it had no effect so I have powered down and will reboot after a bit to see if it changes anything.

Offline Tweakie.CNC

*
  • *
  •  8,022 8,022
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: Steps Per seem wrong, Halp Plz
« Reply #6 on: October 07, 2015, 04:30:32 AM »
You may need to read your manufacturers instruction but I don't think you should be changing any of the drivers dip switch settings without the unit being powered down first - that is certainly the case with all the drivers I have used.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline RICH

*
  • *
  •  7,380 7,380
    • View Profile
Re: Steps Per seem wrong, Halp Plz
« Reply #7 on: October 07, 2015, 06:25:08 AM »
You don't say what drives you are using.

The Gecko site has good information on the basics of using stepper motors so go there and read / study the information.
There is nothing gained by micro stepping greater than 10x as the motor can't position to accuracies greater than 10x, thus it's of no value
from a motor point of view. Yes, the drive may be able to break a step / pulse into smaller values, but, the motors rotor can't rotate to that
smaller fraction of a step.

If you are interested in resolution ;ie an extremely small accurate move with a stepper, that can only come from the  mechanical components of the system.

RICH