MELF

[mrandt]

Hi Juha,

according to Juki Nozzle Catalogue (http://avipre.com/products/smt&tht/juki ... Rev-C3.pdf) their recommended nozzles for MELFs are type 510 and 511 depending on diameter.

Those nozzles have in fact a V-shaped, almost rounded tip:

juki_510.jpg (21.83 KiB) Viewed 2563 times

I think as in intermediary solution something like that could easily be made from a piece of plastic tube.

Glue the plastic tube onto a blunt needle with luer lock, sand the tip flat, finally use a fast rotating drill bit with the desired diameter (same as MELF to be used) to carve the shape into the tip - done.

The A homing needs to be done anyway, an automatic nozzle change (Which I'm looking at) can't work without it.

I think there is a simpler solution once we implement automatic nozzle change:

Under the one assumption that all nozzles should be in the tool depot when machine starts up (no nozzle connected to coupler), we do not need A homing.

It does not matter which rotation the nozzle holder might have until it is actually connected to a nozzle.

The nozzle orientation in the depot is well known - the Juki nozzles have guides to enforce a certain orientation while they are in the tool depot:

juki_guides.png (9.82 KiB) Viewed 2563 times

So once the coupler picks up any nozzle from depot, we know the nozzles orientation and can just reset A to 0° after tool change.

If we want to be on the safe side, we could return all nozzles back to the depot before closing LitePlacer software - and display a corresponding warning to user if power TinyG is disconnected prematurely.

In that case, user would have to manually remove the nozzle and put it back into depot - a minor inconvenience in my opinion.

If we are more daring, we could also just rotate A axis back to 0°before LitePlacer closes or disconnects from TinyG and assume it is still there on resume. This would work unless someone manually interfered with A axis position (e.g. by rotating nozzle by hand).

Regards
Malte

[jarekk]

I should have somewhere Siplace nozzles for melfs which could be used instead of needles.

But these are directional - you would need one more sensor or calibrate it with camera after assembling ( using e.g. color dot)

Anyway - all small pitch Siplace nozzles are directional - to get better grip of small parts as the hole is rectangular.
Let me know if you are interested, should be pretty easy to make adaptation for LitePlacer.

I could send Juha (and others interested) samples of different types - for testing