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Erratic machine behavior
« on: January 31, 2011, 09:28:30 AM »
hello all
New here to the forum. I'm having problems with my machine, b.t.w. using aspire and saving my toolpaths as gcode*tap inches, x and z axis slowly move and when i try to home back it takes me to a diffrent position than what i originally set it as.  I calibrated the steps at around 3994 for one and 4000 for the other with Machs step calculator, but i could never get true accuracy, for instance, say i asked to move it an inch it moved it to .994 and it would reset it. I would then ask to move again and it would move 1.002 and so on.  it never moved to one inch exactly.  I don't know if this is part of the problem or not.  I am going to crank up the power to my motors, as i was reading that they may be underpowered and skipping steps.  As for now I'm bummed, because i can't use it. I did the tutorial that mach comes with,(roadrunner) and it worked fine. its when i load these 3d's. it goes maadd.  Not sure if its a communication conflict or a calibration adjustment.
My machine is a fla100, by Nate Lowry.  Any thoughts and comments would be appreciated

Offline Hood

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Re: Erratic machine behavior
« Reply #1 on: January 31, 2011, 11:51:26 AM »
Have you got the Direction Low Active setting the correct way for your drives?
You may need to detune your motors a bit, ie lower the accel and Velocity by half and see if that helps, if it does then try increasing until you again have issues then drop down a bit.
Hood

Offline Tweakie.CNC

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Re: Erratic machine behavior
« Reply #2 on: January 31, 2011, 12:26:11 PM »
Tiofilo123,

As you say it goes madd when you load the 3D's, I have a theory. Please excuse me if I am wrong (don't want to upset anybody here) but there are issues with the pirated version of Aspire and the post processor GCode (I think the writers were a bit cleverer than the crackers thought they were). Could this be part of the problem ?

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Erratic machine behavior
« Reply #3 on: January 31, 2011, 01:21:35 PM »
Tweakie
I have a regisgered version of aspire  cost me 2K  thanks  for your concern. Still im still waiting on a reply on their part im running my motors at 115in/min. They sound good. I was going faster 140in/min and the motors sounded good no skiping etc. As for changing the dir do i change all of them or one at a time to see if it works

Offline Hood

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Re: Erratic machine behavior
« Reply #4 on: January 31, 2011, 01:43:16 PM »
It is the active state of the Direction pin, if you have the same drives on all axis  then they should all be the same, which way will depend on what your drives require so look at their specs. If you have to change any of the Dir signals active setting then you will need to go to Config then Homing and limits and change the reverse setting to the opposite of what it is for each axis you have changed.
Hood
Re: Erratic machine behavior
« Reply #5 on: January 31, 2011, 03:02:54 PM »
hood
not sure if im following you, let me explain whats happening.  Once i upload the gcode  it begins to run fine, after a couple of miniuts i notice that the x axis is shifting to what i think is positive and the z axis slowly move up to the point that it no longer touches the material.  When i press home it goes to a diffrent point.  What i don't understand is why it works with the roadrunner pattern.  t Ill try to change the dir first

thanks

Offline Hood

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Re: Erratic machine behavior
« Reply #6 on: January 31, 2011, 03:15:33 PM »
It does sound like your motors are losing steps, it could possibly be due to the active state being set wrong for your drives, whether it should be active high or active low will depend on your drives. (see pic for active Hi/Low setting )
Other things to look for is maybe you need to increase the Pulse Width and Dir prechange, try 5 for that and see, its on Motor tuning page.
Also as it seems like its when three axis are moving, check that your power supply is providing a stable voltage whilst all three axis are in motion, it may be your voltage is dropping off and making the motors lose steps.
Hood
Re: Erratic machine behavior
« Reply #7 on: January 31, 2011, 03:25:53 PM »
changed the dir to active and motors move in the opposite direction as my keys, watching the video to see if i can change the direction
Re: Erratic machine behavior
« Reply #8 on: January 31, 2011, 03:28:32 PM »
is step pulse is the same a pulse width

Offline Hood

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Re: Erratic machine behavior
« Reply #9 on: January 31, 2011, 03:29:13 PM »
Change the Direction of the motors from Config menu then Homing and Limits, change the reverse to the opposite of what it is now and your motor will go the right way.
Hood