Old Guy

[Old Guy]

Hi Guys!

At the shop where I work we recently became aware of a problem in one of our EZTRAK machines. We had a motor that was vibrating as it moved ( Y axis) and this seemed to be the cause of a driver board failure. I replaced the board and noticed that the motor still had a vibration in it when it moved. I then swapped motors and the vibration followed the motor to the X axis. Another motor was ordered and installed, The vibration problem disappeared. While working on a long part with holes 29 inches apart I noticed about .060 error on the machine. Since the majority of parts that we make on the machine is about 4 inches or less this error was never really noticed (I just adjusted the program the few thousandths to bring it in spec). Since this problem has come to light we checked another EZTRAK in the shop and It HAS THE SAME ERROR over a 29 inch move the machine was off about .060. We had all noticed that on a circular move we got an eliptical hole (about .001 to .002 difference) till now we just lived with it.
Is this a common problem?
Is there an easy fix?
Thanks!

[Al_The_Man]

You didn't mentiopn what type of motors you have, often vibration is caused by too much amplifier gain, but in your case the motor cured the problem?
If you have a progresive error, i.e. the farther you move the larger the error, is usually caused by a resolution setting problem, counts/inch, if this is the case there should be a parameter setting to cure this.
Al.

[machintek]

Vibration while moving can be a dirty tach.
The original EZTRAKs did not come with software for pitch error compensation. From about software version 3.02 you did have pitch error compensation.
Does it have a hard drive? Disk on chip? Disk on module? Or just a floppy?
At main screen, press the * key, enter the code 11235, press ENTER twice and you should see the parameters for travel, backlash, and pitch error.
You can also tune the drives, but I do not know how confortable you are with this.

George

[NC Cams]

Had similar problems with mine. Sounds like you need a visit from somebody real familiar with EZTRAK servo and gib tuning.

Not a DIY project if you ask me as I watched and learned thru the whole process when mine was redone. Motor drives need to be tuned to the particular motor as they all respond a bit differently. If they are not tuned, they'll not cut round or straight or repeatably.

Lead error will accumulate the longer you travel. This adjustment was part of the tuning process by our service guy.

Brian at BPT Machine in Carol Steam IL did our 'TRAK (we're in Michigan) and it is deadly accurate now.

[mangalmoorthy]

Originally Posted by Old Guy Hi Guys! At the shop where I work we recently became aware of a problem in one of our EZTRAK machines. We had a motor that was vibrating as it moved ( Y axis) and this seemed to be the cause of a driver board failure. I replaced the board and noticed that the motor still had a vibration in it when it moved. I then swapped motors and the vibration followed the motor to the X axis. Another motor was ordered and installed, The vibration problem disappeared. While working on a long part with holes 29 inches apart I noticed about .060 error on the machine. Since the majority of parts that we make on the machine is about 4 inches or less this error was never really noticed (I just adjusted the program the few thousandths to bring it in spec). Since this problem has come to light we checked another EZTRAK in the shop and It HAS THE SAME ERROR over a 29 inch move the machine was off about .060. We had all noticed that on a circular move we got an eliptical hole (about .001 to .002 difference) till now we just lived with it. Is this a common problem? Is there an easy fix? Thanks!

Hi,
Saw your quote. Actually when the vibration occured had you checked the Servo Gain parameters. Because with servo gain not properly set vibration may occur that is one part.
Now you have changed the motors so it obivous that the positioning error will come because there is pitch error compensation still on in the parameters. Also when the motors is changed then the machine should be definatly go for Laser calibration to get accuracy tuned according to new motors that is part 2.
When u go for circular interpolation eliptical path is appeared then ofcourse if positional accuracy is not o.k 100% eliptical path will occur. Also even Servo gain tuning is required with the help of Ballbar accuracy testing.
Regards,
Mangalmoorthy.A
(Head calibration department)

[reabdet21]

I know this is an old thread but I recently got an ez trak, 1998.

I notice that when I move the y axis with the jog controls, it makes quite a bit of noise that the x axis does not. After reading this thread, that may be vibration noise I am hearing. It sounds almost like a grinding noise. If anyone is reading this thread, I would like some opinions of what is causing the noise. Thanks, Jim