Waffle Tray max size

[basemetal]

We are placing a load of thin quad flatpacks 10x10x1 in waffle trays. We made an 8 x 8 tray and set the 1st and 2nd refs, but the picking gets progressively more offset the further we get from the refs. The x and y pitch for the waffle tray when we 'made' it is spot on, so i am wondering if the machine software for the waffle tray is limited to a specific size or a specific number of y direction 'lanes'.

If we set up each individual position bias (64 of them !) then it picks spot on, but then we need to fit in the next tray 

Anyone experienced this?

[trev]

I think once it learns the position offsets for each location it remembers them. I had it with a TQFP tray. Double pick on each one to start with but then it remembers fine and not had an issue since.

[Mike]

You did set "lock feeders" didn't you...?

[basemetal]

Thanks, yes it did double pick and correct but when we remove the tray and put a new one in we don't always get it back in exactly the same place so we have to reset the references - looks like we will have to make a jig for the trays.

Feeder is locked so its not trying to self correct and error stack.

After this job i will see what's going on and post. My head scratch is that all the x and y dimensions for the feeder are correct but it still progressively gets more and more off center.

[Mike]

What I do with trays is stick an empty one onto the base with double sided tape, then place a second tray on top - as they lock together, the alignment is good when replacing a tray. 
No need to make a jig - the tray is the jig!

[trev]

I used to get drift.

I think it's related to a bad cdf file setup and always perform a re center of the head at the start of each day. I usually do focus, re center and realign functions.

.

[basemetal]

Great tip Mike. Thanks!!