Re: MELF
Posted: Thu Nov 26, 2015 9:36 am
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:
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.
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:
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
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 2565 times
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.
I think there is a simpler solution once we implement automatic nozzle change:JuKu wrote:The A homing needs to be done anyway, an automatic nozzle change (Which I'm looking at) can't work without it.
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 2565 times
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