Juki Nozzle Spring

[Mangozac]

As I'm sure many of you are aware, Juki nozzles are spring loaded. We have been setting things up so as to avoid the spring compressing but I'm curious how necessary that is. We have tried having the spring compress a little when placing the component and it doesn't seem to have had any adverse effect. What's the general recommendation?

[SMdude]

You want the spring to compress a little as it then accounts for the part to be a little lower in the strip and it presses it slightly into the paste on placement.

If you make it just touch, you get mis-picks galore.

[Doctorandus_P]

Spring loading is done to make a reliable connection in spite of always existing tolerances.
Mechanical things move, they always do.

If you put in a roll of new resistors from another manufacturer there may be slight differences in thickness of the tape or even the resistors themselves. The feeder may be slightly moved after you put it back etc.

[Mangozac]

Thanks guys, that's what I was thinking. For parts less than say 1.5mm height can we just set the placement Z-height to be where the nozzle just touches the top of the PCB and let the spring compress? Obviously for taller components we need to provide some offset.

[Doctorandus_P]

The nozzles are designed to be compressed a bit.

Why would you even consider it would have "adverse affects"?

[Mangozac]

Why would you even consider it would have "adverse affects"?

Because I do not know how much they are intended to be depressed and I want to ensure that it does not disturb the part during placement. I am pleased to hear that they can be compressed considerably though