Right... like with the newer of our two bed routers today. The manufacturer's 'solution' was that we had damaged and sticking slide rails and ball screws on the (two!) Y axis drivers that are served individually by two different homing switches. I've been telling them for months that homing was not reliable, and they said that their home switches 'never fail'.
Today I had to unbolt and realign the gantry AGAIN because the two Y servos were reporting over-current. They again claimed dirty slides and ball screws, and improper lubrication. We scrupulously maintain both conditions.
So I wrote an exerciser to challenge their position. I realigned the gantry - which is laborious - then ran FIVE HOURS of intensive Y-axis exercising on the machine. No errors. I homed it ONCE, and it blew an over-current fault on one of the two Y drivers, and showed a pending fault on the other.
Why? Because the two old home switches aren't switching at the same position every time they're actuated. One time they may switch at the same time. The next, they may switch with the gantry skew by 40-50 thousandths, end-to-end... and that causes the two servos to fight one-another trying to maintain position.
I proved it several times, then challenged them with the results. They said, "Well we guess that _could_ happen, but we've never seen it." What I know is that hundreds of customers have lost thousand of hours of work time to imagined failures to maintain their machines, when these damned switches have been failing all-along.
My WORK-AROUND is this. Until I get new parts in, I'll do only one home operation at the beginning of a day. If the currents on the two drivers are excessive, I'll do a gantry realignment. If it's OK, I will NOT DO ANOTHER HOME for the rest of the day.
That's a 'solution' Arie, by means of a work-around.
Lloyd