Nozzle Tip as actuator

[Ben Whitman]

A somewhat hacky idea I've been discussing with some folks on the Lumen PnP Discord server is the idea of using the nozzle tip to actuate a drag feeder.  Currently, we're able to make this work by creating a dummy actuator with the offsets of the nozzle tip.  However, this isn't ideal, and so I started thinking about what would need to happen in order for a nozzle tip to be properly usable as an actuator.

- The actuator would need to be assigned to a nozzle TIP, not the physical nozzle.  The reason for this being only certain tip diameters are actually compatible for this use, and also it should work regardless of what nozzle that tip is actually loaded onto
- The nozzle tip actuator would need to be able to recognize if a part was already on the nozzle or not, so as to not attempt actuating with a part on the nozzle
- The movement planner would need to be able to account for the case where only a single nozzle tip is compatible as an actuator on a multi-nozzle head and execute all feeder actuations before trying to pick a part with the actuator nozzle

At this point, I guess I would consider this a "request for comment" as to whether or not the idea is feasible, whether there is any interest in adding it, and if there are any other interactions with the rest of the machine that would need to be accounted for in order to properly implement it.

[mark maker]

Hi Ben,

yep, that's more or less how the BlindsFeeder does it for cover actuation.

It is quite complicated in order to prevent stupid nozzle tip changes, but some code could probably be reused from here:

https://github.com/openpnp/openpnp/blob/370b98b3043fa4b735039899ea1ebee76621ddc3/src/main/java/org/openpnp/machine/reference/feeder/BlindsFeeder.java#L1437-L1503

The setup is already there. When I added that checkbox, I anticipated that someday, somebody would want to use it for dragging, hence the labeling "Push & Drag allowed", see screen-shot:

https://github.com/openpnp/openpnp/wiki/BlindsFeeder#allowing-the-nozzle-tip-to-push-the-cover

I would suggest adding that facility to the ReferencePushPullFeeder. It can be easily configured for drag (a.k.a. "pull") feeding.

Semantics: if no Actuator is given, it should use one of the allowed Nozzle tips, as in the suggested code above.

The needed mechanical motion can already be defined with that feeder. A cover tape peeling spool can also be driven either by actuator or by rotation axis, coordinated with the drag motion:

https://github.com/openpnp/openpnp/wiki/ReferencePushPullFeeder#coordinated-peeling

And it has optional sprocket hole based vision, optional OCR/Barcode etc. cloning settings support, one-click setup from the second feeder.

https://youtu.be/5QcJ2ziIJ14

https://github.com/openpnp/openpnp/wiki/ReferencePushPullFeeder

_Mark

At this point, I guess I would consider this a "request for comment" as to whether or not the idea is feasible, whether there is any interest in adding it, and if there are any other interactions with the rest of the machine that would need to be accounted for in order to properly implement it. --
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/fd0b8933-6a4a-4bfb-85aa-1295342abe7dn%40googlegroups.com.

[Ben Whitman]

Ah, I wondered what that "Push & Drag Allowed" checkbox was for.  As far as the cover tape peeling goes, we're actually working on a design that is driven directly by the tape holes using a sprocket wheel, so the nozzle handles everything on its own (ignore the heavy deflection on the nozzle, there's a lot of friction in the gears and I'm working on that).  I've gotten it to work both using the PushPullFeeder as well as the DragFeeder options within OpenPnP.

https://youtu.be/Lcgl914GEfg

[Litterio Andrea Guainella]

Hi Ben,

>  I've gotten it to work both using the PushPullFeeder as well as the DragFeeder options within OpenPnP

For test I printed this but I am little bit confused for configuration in openpnp.

Please share a screenshot with full configuration about feeders. Thank you

LAG