Need Help!- EZ-Trak Trouble...again

[doctordemo]

My X axis has been acting up for some time and has reached the point where I need some help.
When the table moves , it is jerky. If I make a move I can't always get it to stop where I want it with out turning the travel dial back and forth until it settles down.
To rule out the servo, I plugged the X cables into the Y Servo and the problem followed.
I don't know if it is a cable or if the problem is inside the cabinet, or exactly how to check it out.

Any help would be appreciated

Steve

[machintek]

Try this first. Take apart the armature cable connector for the X axis motor. I am refering to the connector on the cable, not on the motor. There are some heavy wires there and some thinner ones. gently tug on the thinner ones. One may have broken. These are for the velocity loop (tach). Solder it back on if broken.

George

[doctordemo]

George, Thanks for the heads up. I'll check the cable I can only hope it's that simple, it hates Me.

Steve

[doctordemo]

George, I tried Your plug/wire check and everything seems to be pristine. I even tried to move the wires while moving the table and it didn't have any effect on the chatter.
I would really like to do some more ''easy'' trouble shooting before I make up new cables, but I'm not sure what I should do next. Board swap?

Steve

[jmelson]

Originally Posted by doctordemo George, I tried Your plug/wire check and everything seems to be pristine. I even tried to move the wires while moving the table and it didn't have any effect on the chatter. I would really like to do some more ''easy'' trouble shooting before I make up new cables, but I'm not sure what I should do next. Board swap? Steve

Well, these are BRUSH tachs, so the brushes could be shot. Most of them use silver wires that eventually wear through from rubbing on the commutator. Or, it could be the motor brushes themselves. or, it could be a loose wire or dirty connection at the servo amp end. Possibly gently tapping on boards/connectors with the plastic handle of a screwdriver will show where the bad connection is. And, of course, it could actually be the wires in the cables have become fatigued/broken. You could try ohming them out while moving the cables.

Jon

[doctordemo]

Jon, thanks for Your thoughts.
I have ruled out the motor end, it is either in the cables or a problem inside the cabinet.
My Y axis works flawless, if I plug the X cables into it the problem shows up on Y.

Steve

[holbieone]

your drive card may need to be re tuned

it's easy to do if you can get the procedure

[doctordemo]

Originally Posted by holbieone your drive card may need to be re tuned it's easy to do if you can get the procedure

I have heard that before, but I don't have any information as to how to do it.
A online friend has a mill that tells him when it needs a tune up, but it isn't a BP.


Steve

[doctordemo]

Still not working and getting outside My comfort zone with trouble shooting.
Well I took the cable out of the machine ,cleaned it up and inspected it. No kinks, nicks or pin holes.I sat down with an ohm meter and checked it out and couldn't find anything wrong.During the process of checking , I found that it has 8 pin plug at the motor end and 10 pin at the board. Closer looking revealed that two of the wires go to the ground wire inside the shield wrapping at the board end and are not connected at the motor end, but I guess they don't need to be .

I did learn while trying to find the problem that if I unplug the tach cable while the table is moving it hauls a$$ to the limit switch.

Steve