4th Axis encoder problem?

[Scanfab]

We bought a used FADAL DC 4th axis, and when installing onto a 4525 it gives a-axis error #1. Wont let me jog any axis, always tells to release estop problem. When initiating CS in command mode, the 4th axis WILL turn around about one revolution before stopping and giving error msg. My father, good with electrical(CT scanner repair ect.) checked the power cable, all contacts from pins to servo look good, shouldn't have a broken wire. Im guessing ther power feed is ok because it does spin after CS. The machines servo disconnect card works fine with other 4th axis.

Do i need an encoder (or whatever the piece is called) to fix the problem.?

[bl409]

Scanfab,
Have you checked the connentions where the cable attaches to the motor and resolver wires? I have have some bad connections at that point before and it caused several alarms. You might also check the way the motor and resolver cables are attached. If they are wired black to black and red to red the resolver wire are wired one way and if they are wired black to red and black to red they are wired differently. Good luck. BL

[Scanfab]

I'll have a look at the resolver wires, I did look that the red goes to red and black to black with both having a small white wire in between. Thanks..
Do you think changing the resolver would fix the problem?

[carbidecraters]

I'll have a look at the resolver wires, I did look that the red goes to red and black to black with both having a small white wire in between. Thanks..
Do you think changing the resolver would fix the problem?

So your 4525 is a AC machine and are you using a DC card? The AC machines can go AC or DC but the DC machines can only go DC for the 4th.

[bl409]

Scanfab,
I had a cable go bad with a vh5c DC rotary. I had a local Fadal Service Guy come in and take A look at it. He checked the connections and then rewired it the opposite way it was hooked up originally. Long story short I had to change the cable after changing several other parts and He had hooked up these wires incorrectly and It acted very similar to yours once I got the original problem fixed and the crossed wires was the only problem left. Good luck. BL

[Scanfab]

Yes, an AC 4525 with a DC 4th axis card whick is mounted to the cabinet wall, not in the card slot under X,Y,Z amps. Though the power feeds to A and B are in the card slots. Maybe this was trendy in 2003, who knows..

I tried switching the power feed wires and the resolver wires back and forth, all different combos. Sometimes 4th axis servo mover a twitch, sometimes faceplate moves 90'. Still need to try something else, hmm I wonder what...

[dango]

I think you are mix two thing
there is resolver on the motor and there is
tacho and motor
the resolver has about 6 wires
the tacho had 2 wires and the motor had 2 wires
since you got dc motor on ac machine you need to have on
the motherboard I think is number 1060-0 a small card for the resolver
look at right corner at the bottom
without this card your A axis will not work

[Scanfab]

I pulled a working resolver off another DC 4th axis and the servo now works, a bit noisy at 100% rapids but not bad (quiet) at 50%.
Ordered a new resolver for it...

How do you adjust the backlash between the worm gear and ring gear, I played with the adjustment to take some play out, but what is the correct "value" I'm looking for? Of course I checked the whole revolution so it doesnt bind at any point..