[zcases]

I have a VMC15XT, ~1995. I don't see any references to my specific symptoms when I search but jeez I have to believe this has been seen many times before.......

X axis vibration, during a G1 move most noticably. 400 ipm very noticable, which is the same as the rapid move right? So then.....

A G0 move is smooth as butter , with the exception of the accel and more notably the decel move.

I swapped the X and Y boards, see the same vibration exactly.
I swapped the X and Y AMPs , see the same vibration exactly.

Anyone experience this before? Hoping for a warm comfy feeling I can just buy a resolver or something and get back to making chips.....certainly appreciate any feedback!
Scott

[Jim Dawson]

It does sound like a resolver issue, but it could be mechanical. Rotate the lead screw by hand and see if you can detect any roughness.

If the lead screw seems OK, then I would say resolver or encoder, which ever it has. But....if it has a resolver, it may need to be timed to the armature.in order for the motor to comutate properly. That would be best done by a motor shop that does servo motors.

Normally what you find in the resolver is a bad bearing, the slightest tick as it rotates will foul up the works, I have seen this happen many times.

[DareBee]

If that is still a DC machine, may just be dirty brushes

[zcases]

Affirmative , DC. I will do some checking tonight, thanks guys. Hope to give some good feedback here soon.

[Jim Dawson]

Affirmative , DC. I will do some checking tonight, thanks guys. Hope to give some good feedback here soon.

That's good to know, that means that you don't have to worry about timing resolvers, that only applies to AC servos. You proabaly have encoders on DC servos.

[DareBee]

Yes, DC uses resolvers.
AFAIK 95 was the transition year between ac/dc and both were available

[zcases]

Well as it turns out I had resolvers, and I just purchased new AMCI resolvers to replace the OEM Harowe units.

New dilemma: The wiring colors do not correspond! Has anyone used the AMCI replacements? I see every Fadal parts place sells them, and all look like the same wiring as what I received, so I think I need to get lucky and someone knows what wires correspond to the colors of the original resolvers..........fingers crossed.

[Jim Dawson]

I can't help you with the wiring, but I did run across this tonight regarding resolvers and DC servos. You might want to take a look at Chapter 4, there is a procedure for timing a replacement resolver. This is specific to a Kollmorgen DC drive, but maybe worth a read. Not sure if this applies to your system at all.

http://www.kollmorgen.com/uploadedFi...ds4install.pdf

[rodney247]

All Fadal manuals can be downloaded from Flint Machine Tools, Inc. or Independent Technology Service have wiring information