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vfoe

art421

Aluminum
Joined
Sep 18, 2010
Location
nj usa
I have a 1994 vfoe and it seems to be losing position on the x axis. For about 4 months my lead man has been telling me the x is shifting. I didn't believe him because when he screws up he usually lies or forgets how to speak english. After running a job myself for 2 days the x axis seems to creep over to the minus side in small amounts until it gets out of tolerance. I checked everything else myself like bolts and stops. I even swiched the stop from right to left side it still moved the same way. The y doesn't seem to move. anybody have something similar happen?
thanks
 
Hello,

I have 3 vfoe machines, 96 and newer, never seen that happen. Never had to adjust the backlash, but I think that would have an influence from startup in the morning.
Is the X axis loud, perhas your thrust bearings are getting hot. If you do not know the most likely thrust bearings are in between the motor and the lead screw. You have to replace the bearings and the housing as a kit, Haas will not sell the bearings but the assyembley is somewhere around $300 u.s.
Also check to see that everything is getting lubricarted, there are meters on the right side just under the table. The ball nut also has meters, anything not getting oil is going to get hot but I have never had anything under there fail but I have replaced a couple of thrust bearings, your machine is getting real old, "give it some love"!

Landm1
 
I think I would add a feature or hole on the machine table you can test against when you suspect this to see exactly how much it is moving. Maybe you are moving your fixture in the T slots in the table?
If you do determine the X is moving, there are thermal comp corrections in the parameters for that IF you determine the X mechanics are normal and not heating up and causing the problem. Warm thrusts doubtfully would cause this but a hot screw WOULD cause this.
 
thanks for the suggestions. I set up a job yesterday and ran it all day, seemed to have no problem. This morning at start up I got alarm 165 x axis return margin too small. I jogged it away then sent it home. The first pcs. off the machine were off by .25 on the x. This pc is machined in soft jaws and I cut both ends so a .01 shift would be nothing, but a .25 shift is alot.
I had the service guy in about a month ago and he said the x cable was showing wear. I taped it up and turned the rapid down to 50% maybe the cable is bad?.
 
Usually that error is attached to a limit switch error. I would slide the X covers back and manaully toggle the switch to see if it is functioning right. I would also check the plugs in the back for chips. There are 3 white 2 wire plugs just in front of the luber box. Those are the plugs fhr the X, Y, Z and are marked as such. They are ignorantly left open for chips to get in and short the switches.

I have to doubt that the X servo cable is the problem because encoders work with a redundant self check called the "not channels" so if an encoder just has a hickup, the control will see it and alarm. Since the machine has never stopped on you but you indicated that you lost .25 in part zero when homing, that is coming from the switches most likely. If they are sticky, lube them and run them.
 








 
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