Hello Guest it is June 16, 2019, 03:30:38 AM

Author Topic: gecko540 problem under mach3  (Read 14694 times)

0 Members and 1 Guest are viewing this topic.

Offline RICH

*
  • *
  •  7,337 7,337
    • View Profile
Re: gecko540 problem under mach3
« Reply #60 on: October 10, 2011, 09:15:29 PM »
oops, forgot to ask,
I assume you have the PC  bios set to EPP mode??

RICH
Re: gecko540 problem under mach3
« Reply #61 on: October 10, 2011, 09:16:56 PM »
yes Optiplex GX520

Re: gecko540 problem under mach3
« Reply #62 on: October 10, 2011, 09:17:22 PM »
oops, forgot to ask,
I assume you have the PC  bios set to EPP mode??

RICH
yes  i have

Offline RICH

*
  • *
  •  7,337 7,337
    • View Profile
Re: gecko540 problem under mach3
« Reply #63 on: October 10, 2011, 09:37:33 PM »
I have asked a lot of questions and will given you my take on the whole system. Not today.
We will then try a few tests .

I do have a concern though....that DELL GX520 has on-board graphics.
I spent hours trying to find a fix for that computer, I know since i tried to use that one for CNC. Works great for everything
EXCEPT cnc here. Mine put a bad  pulse signal ( ringing )  out to the drives and the result were missed steps, low velocity, etc. There is nothing i could to fix that  problem on mine. Yes it worked along with a SmoothStepper.

Stay tuned....till tomorrow,
RICH

 
Re: gecko540 problem under mach3
« Reply #64 on: October 10, 2011, 09:42:49 PM »
ok

Offline RICH

*
  • *
  •  7,337 7,337
    • View Profile
Re: gecko540 problem under mach3
« Reply #65 on: October 11, 2011, 07:20:55 PM »
komar1970,

COMPUTER
1. I have major concerns about your Dell GX 520 since I have that one and also tried other Dells and found them to be
problematic for CNC use. All the comments that follow will assume that the pc is not a problem.
So trying to set the steps per unit correctly will be useless if one of the main components of the system is bad.
Skipping steps, reduced velocity and accel are just a few tell tale signs. It would be nice to be able to
substitute / try a different pc ( no laptops or  other Dells)  to confirm.  You could use a digital o'scope to have a look
at the pc output signal.

2. Even though you do have the Bios set for EPP mode per Gecko recomendations, there is no way to  remove
   the signal which is causing a bad pulse. You may be able to use a different video card and pp card.You can also
  use an external device such as a SS, but, I would recommend a new / different computer at current pc prices today.

3. Your pic of the driver test at 25k seemed ok ,but what happens if you move your mouse, I am also guessing
that the kernel speed is probably changing significantly when running Mach.

4.BTW, never noted that you have a break out board, etc. , so I assume the connection path is pc to drive to steppers.

  
MACH
1.Suggest that you upgrade from 2.58 to a current lock down. Have a look at the current revision listing to see all the
changes that have been made.

2. Configuration - based on your xml file that you posted:
   Steps per unit - 400 is correct based on calculations.

3.  In the attached xml i changed the velocity  to 250 / accel to 100 / step and dir us to 4
    Couldn't find a recommended pulse and step setting for the drives, would think that 2us would be min and
     longer like 3-5us should be ok.

4. Fix the attached XML since you have wrong pins assigned:
   - for input signals you are using PIN 16.....( must be 10,11,12,13,15)
   - for output #2 you are using PIN 1....( only use the pins that are listed below the table)
   - Do not duplicate Pin assignments
  

DRIVES- MOTORS - POWER SUPPLY
1. Don't think it's a G540  drive problem. Swapping cables to different motors would quickly pinpoint if there was a bad drive.

2. Couldn't find a recommended pulse and step setting for the drives, would think that 2us would be min and
   longer like 3-5us should be ok.

3.The 3.5 K resistor provides for max drive current output which is ok.

4.You have 3 motors wired in series @ 3.5a each. ( 3.5 x 3=10.5 amps max x60%= 6.3 or more required min)
   6.3 amps x 48 volts =302 watt supply. Your switching supply is rated at 400 watts. So  the power supply
  should be  is adequte in both voltage and amps. We will only test one axis so more than enough.

3.Same motors for all the axis. You never remarked about the Z axis. Dosen't matter since we only want to get
  one axis running correct at this time and the others can  follow later.

4.I found info on your motors from the EBAY info link but here is a link specific to the motors  
 http://www.modelshopcnc.com/index_files/motors.htm.
 You have them wired in series and the drive current is set appropriately for the motor. No motor curve is
  available, so what actual torque &  rpm relative to the  stated 620 in / oz  is not known.  
 Will just need to find what  the max velocity.  

Mill - AXIS COMPONENTS
1.Don't have any comments on the X3 mill. Run out of the end mill is not a concern at this time and can be addressed later.

2. Ground NSK  C1 16MM  PINCH 5MM is high end on the lead accuracy and with a matching ball nut you should not have
   linear inaccuracies during axis moves unless the step per unit is incorrect, the screw is not manufactured to spec or worn,
  or you have axial play in the thrust bearings. You will always have some small amount backlash.
  Thus i will assume that the ball screw is mounted   / supported correctly, and the bearings are preloaded.

 You did note that the  backlash was: Y axis  is 0.01mm ( .0004")  and on X 0.017mm (.00067")

So given the above see my next posted reply,

RICH
« Last Edit: October 11, 2011, 07:24:55 PM by RICH »

Offline RICH

*
  • *
  •  7,337 7,337
    • View Profile
Re: gecko540 problem under mach3
« Reply #66 on: October 11, 2011, 07:46:15 PM »
komar1970,
I would like see what the max velocity is using the DEll.
So try jogging for say 75mm ( i set the hot keys up in the xml and you can change them as you wish) starting with the 250 velocity and increase
it by doubling it until the motor skips. Don't change the acceleration value. Post the value where the motor skipped. Then change the velocity to
1/2 the value were it skipped, save settings, and post the max value.

You already played with the steps per unit. You should not be seeing the errors you are seeing with the type of ball screws you have.
Maybe try with saved velocity value from above and again post the results.

Now go borrow a PC from somebody and see what happens when you test using  a different PC and the modified xml from the above tests.
Make sure that the replacement pc has 5.0 v pp and no on-board graphics.

Till then,

RICH
« Last Edit: October 11, 2011, 07:54:41 PM by RICH »
Re: gecko540 problem under mach3
« Reply #67 on: October 11, 2011, 08:20:39 PM »
whot  it is  i cent  find nothing  pc 5.0 v pp

Offline RICH

*
  • *
  •  7,337 7,337
    • View Profile
Re: gecko540 problem under mach3
« Reply #68 on: October 12, 2011, 06:38:41 AM »
Cam some one using  a G540 comment if the PP needs to be 3.3V or 5.5V?

komar...Some PP's are dual voltage and provide a switch for selection. Most new pc's are 3.3V. New cards can be purchased which
are 3.3V or 5.5v or are dual voltage. Your Dell is 5.5V.
RICH

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: gecko540 problem under mach3
« Reply #69 on: October 12, 2011, 12:26:39 PM »
Cam some one using  a G540 comment if the PP needs to be 3.3V or 5.5V?

Hi Rich,

Quoted directly from Mariss Freimanis on the CNC Zone 04-27-2011 :

"The G540 inputs from the DB-25 connector are designed to work with 3.3V and 5V logic levels."

But I will also add that for me, the G540 did not work as "smoothly" on my laptop as compared to the desktop PC. So I do think that could be at play here depending on the output pulse.

Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)