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My x axis does not jog both directions.
« on: November 30, 2013, 09:41:19 PM »
I,
   have my motor outputs set  x 3 4  unchecked dir low, unchecked step low, step port 1 dir port 1
                           same for    y 5 6
                                            z 7 8 
x will only jog to the minus
y will go + but will only go - if press x in +   
z does the same as y What should steps per be on nema 34 steppers.  and what step puls  and direct puls for each axis     

Offline Hood

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Re: My x axis does not jog both directions.
« Reply #1 on: December 01, 2013, 07:01:37 AM »
As has been mentioned in previous posts you need to trace the wires so that you can see which pins they are connected to on the parallel port, you can then set them up in Mach to correspond .
Hood
Re: My x axis does not jog both directions.
« Reply #2 on: December 01, 2013, 07:46:21 AM »
Hood,
           I am going to trace the wires now.  If I only have x home,Y home, and Z home enabled in input signals could this be the reason?  Should x++ and x-- be enabled with the same port and pins as x home.   As well as for y and Z.   I know I have been posting redundant posts-sorry I'm a little frustrated.  Here is a picture of what I am working with.-Joe
Re: My x axis does not jog both directions.
« Reply #3 on: December 01, 2013, 09:04:25 AM »
Hood,
          sometimes you just need a reminder that you are being a lazy whiner.  I traced the wires to the drives and I had them configured all wrong.  Thanks for keeping me focused.  I don't think the hard limit switches are wired properly, they may have been disabled from the previous owner . I can jog right up to them and nothing happens and they do not light up.  I will trace them later.  I jogged all axis so they were just touching the hard limits and zeroed them.  That zero is outside of the soft limits I set and I was getting a error.  I will watch the tutorial again on homing and limits to set that up correctly.  I was able to load the roadrunner but the motors are not tuned correctly. The y was moving really slow.   If you look at the picture I posted can you determine a calculation for the motors as a starting point? I'm not so firm on how to calculate this.  Do the microstep drivers change the amount of steps or do I start with 200 in the steps per?  The y has an additional gear I don't know what reduction it is.  The x is a 20 mm screw with 6tpi and the z is a 16 mm with 5 tpi.  What determines the proper step and direction pulse #. Is that a spec from the motor?    I know this is a lot of questions.  It is very frustrating doing the blind research.  A few right answers from an expert save hours of frustration.   

Offline Hood

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Re: My x axis does not jog both directions.
« Reply #4 on: December 01, 2013, 10:03:27 AM »
To set up the steps per unit you need to know the motors steps per rev, that is most likely 200 but you can also get steppers that are 0.9 degree, so 400. As said however most likely 200.
You then need to know the microstepping. Also any gearing and finally the pitch of the screws.

If setting up in Imperial units then it would go something like this.
I will give some numbers for this example, yours will be different and only you can say what they are.
200 steps per rev of motor x microstepping of drive x gearing x number of turns per inch of the screw,
 so
200 x 10 x 2 x 5 = 20,000steps per unit.

As said that is just an example of how to calculate, your hardware and settings will dictate what numbers you will use.

There is an alternative and that is use the Set Steps button on the settings page, its just above the Reset button, using that method will only be as accurate as your measuring.


Velocity and acceleration will be trial and error and I can really take a guess at that as it is all hardware dependant.

Hood
Re: My x axis does not jog both directions.
« Reply #5 on: December 01, 2013, 07:33:06 PM »
I,
    looked at the Leadshine drives,  x and z are both set to 8 microsteps and the y is set to 16.  On the left and right y steppers they have a 1 inch 20 tooth pinion spinning a 4 inch 80 tooth reduction gear.  I am not sure how to calculate that?   I am thinking it is 200 x 16 x 4= 12800.   I got the 4 from dividing the 20 tooth into the 80 tooth.  is this correct?  I am also calculating  200x8x5tpi =8000 for y and Z.  at those setting with acceleration and velocity low. Z was perfect when I ran a steps per unit and measured the distance.   The y was way off and running super slow.  Also what determine the step and pulse direction numbers. should they be 1-1?  Do I need to enable an a axis with the same port and pin for the second stepper motor on the y gantry.  I really want to cut something, I been configuring for days.
Re: My x axis does not jog both directions.
« Reply #6 on: December 02, 2013, 08:05:20 PM »
Hood,
          just wanted to share that the machine is working.  I still do not have the correct motor tuning for the y axis.  Am I calculating something wrong?   200(steps per) x 16(microstep driver) =3200.  The 1" 20 tooth gear drives a 4" 80 tooth gear that then drives the 1" 20 tooth paired to the rack.   I assume this gives further reduction? what does this do to the 3200 figure?-Joe

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