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Where do I set the nozzle height for the needle calibration ? I'm starting to think it was a feature only in the rmod version.

> I'm starting to think it was a feature only in the rmod version.

I'm not that familiar with rmod. The standard software uses same height for all nozzles; after all, they are the same height and besides, the pickup and placement Z are measured (or set manually) separately for each tape, so it would not matter anyway.

I meant the nozzle height the machines moves to when taking it to the upward facing camera.

Ok. This is hard coded. It is 0.5mm (my guess for average small component height) above PCB surface level. It doesn't make sense to adjust it until there is a way to adjust the uplooking camera so that we know it is looking directly up, with good precision.

[I've been thinking of something like Logitech 270 with trimmable base as the uplooking camera and a way to tune it perfectly vertical would make it possible to make correction in software so that the Z axis moves directly up and down. That would be a good upgrade - but if we get that, the calibration level setting still doesn't make sense:). Now it would do no good, then it won't be needed.]

I recommend you align PCB surface, parts, strip holders, feeders, trays etc. all at Same Z-level.

Otherwise you will run into trouble with the cameras. Our cameras suffer from projection errors; objects nearer appear bigger, objects further away smaller. So the pixel-to-mm calibration is only valid for a specific distance from camera. Same goes for focus; Image is only sharp at one given viewing distance.

So unless you have expensive, telecentric lenses and wide-range or auto focus; you would not want to use a different Z-level.

To a certain extent Juha's Software compensates this by "homing in" on marks, e.g. in the fiducial detection, until the camera is centered above them. For this iterative process, the pixel-distance ratio is not as important.

However tilted camera axis becomes yet another issue, as Juha mentioned.

Bottomline: Lowering the nozzle to a Z-level slightly above the PCB surface makes sense, I have Not seen a use case for using another height.

Once we get into visual Offset / Rotation correction per part (if ever) we could also deternine the best Z-level depending on the height of the given part - which would be part height above PCB surface so the pads of the part are in focus and at the one Level for which we calibrated px-to-mm... But that is a while different Story