xy cutting problem

[melzer]

I got problem on 4020 machine

This is finishing problem when I make a cut in straight line

The finish is o.k.

But when I make the cut with two axis together

I got wavy finishing
did somebody had problem like this

[Neal]

Melzer--
The most common cause of the this is the axes balance not being adjusted properly.. I would suggest running service program O5811 and re-tune your amplifiers for balance and following error.

Neal

[melzer]

Thanks Neal
But I already adjust the gain
Exchange the axis card also the amplifier
Change the clock card
Exchange motors
And I steal got the problem

[Neal]

Melzer--
In that case, check the retention PSI of the tool holder bellville stack. Also verify the Gibbs and straps on all axes. There maybe some lost mechanical motion. Verify the coupler play and any thrust bearing end play.

Neal

[melzer]

this is strange problem
I ckecked everything and replace motors
replace bearings on ballscrew
but the problem is steal there
I can here the huming of one of the motor
when I mke cut in both axis
and I am not feeling it if I move with one axis
but I can not find from where it bcame

[ctate2000]

Did you write the code yourself or post from CAM?

[HuFlungDung]

The failure of a synchronous 2 axis move sounds like a failure of the motion control card, wherever that is in a Fadal.

The axis drive amplifiers themselves should demonstrate a constant fault all the time, as a single amplifier is not really aware that there is another motor (or motors) attempting to move at the same moment, unless there is cross talk caused by broken shields (or shield connections) on an encoder cable.

[Paul_S]

Does it have incoders? A bad incoder could cause this too. Dirty contacts in a servo motor could cause this. (But you said you changed the motors?) Where I work we have one machine with this problem currently. When it is fixed I can make a note here. (We now have 12 Fadals.)

On your display have it set to show lead error instead of percentage of load. Look at the lead error. Note which axis is greater.

[ctate2000]

This could be a mechanical problem. Where I work we tend to blame the electronics on the CNC machines first. Why not, they are the most likely to fail. Could this problem from slop in the mechanical components. Maybe a loose gib, some component in the ball screw and servo assembly. May not show up in straight line moves. Have you checked the mechanical compnonts?

[Dsny]

If this is a DC machine then I would look at your resolvers.

[melzer]

I almost check everything
but forgot to do one test
this is the push pull test so then I found that one of the ballscrew is bad

[ctate2000]

Melzer,

Was the ballscrew the culpret? Are you getting good results now?