Juki nozzle changer with Betz Technik nozzle holder

[Jakob Seitz]

  I am using a head from Betz Technik with the nozzle  holder.

Currently I am trying to implement a automatic nozzle changer with a cylinder moved plate.

In the slow motion video you can see how I want to implement the chaning action with openPNP.

1. Cylinder-plate is in up position.

2. Move to the nozzle slot with X and Y gantry.

3. Move Z axis down to actuate the nozzle holders collar.

4. Move  cylinder-plate down to release the collar. (nozzle attached)

5. Move the Z axis up a little to get the nozzle out of the recess of the fixed plate where they  rest on.

6. Move Y axis to get out of the nozzle holder.

7. Move Z axis to safe-z.

My issue: I made the misstake to test it with a attached nozzle holder and nozzle. Of course it bent the nozzle and motor shaft. I need some sort of sensor to see the possition of the cylinder.

Now my question: Is it possible to make sure that the cylinder is up or down with a sensors for both positions, before the axes moves inside the nozzle changer. To reduce the risk of damage. 

Also I have seen in this google group that @Peter from Betz Technik wants to try a sping with less force to reduce the force on the collar. Is there an update on that?