Need Help!- ATC issue 4020

[kling8]

Running a 4020 program with 8 tools ran good all day till just about quiting time.
tool changes to t3 the key way wasnt lining up on the pod and alarmed out, it worked doing tool change manually, but not running program, put a different tool in and tool changed worked, but ran all day so thinking there is still something wrong with ATC.

do I need to replace guts of pod 3 in ATC

timing off
any advice would be great thanks

[kling8]

So night crew tried changing tool holders and pods last night still had tool change failure, thinking it may be in the spindle end of things if the key way isnt lining up right, going to try again this morning, A bit more info. Changing clips in ATC, and seeing wear on one side more than other, so my timing has to be off somewhere right?
Where to start looking to correct this problem?

[alex gitzel]

There is a orientation arm that engages a notch in the spindle pulley.these bars are known to loosen up and the bearing goes bad sometimes this may be your issue.also check the atc shaft for bearing slop,another good posibility is that the turret motor is worn out,if the turret motor is overshooting the motor should be replaced.the cause of this is the older motors use grease in the gearbox has a break if the grease has thined out it will let the motor go too far,the motor is given a power pulse and coasts to position using the grease to slow it down.even a 1/8 or 1/16 extra on the turn will throw things out. to check look up into the carousel towards the side door with a light and find the 1/2moon and pin driver that is on the motor,hit the turret cw+ccw keys and make sure the 1/2moon part is engaged in the cutout properly and goes to the same position in each direction if it does not this is your issue,you may be able to tune it by changing the turret factor parameter.as to regreasing the gearbox it never seems to work out like it should so your best bet is to replace the motor/gearbox combo.you will need to realighn the carousel if you change the turret factor(loosen the bolts ,put a tool in the spindle and manualy bring over the atc and engage the tool to line it up,be sure it do a m19 in mdi to lock the spindle.).