Paste extruder homing

I have brought this idea up briefly in the past, but haven't put much thought into recently. I was wondering if any controller board (hopefully the Duet because that's what I am using right now) had the capability of an extruder homing command.

This would be specificallyn for syringe based paste extrusion so you could set a maximum extrusion amount to avoid over extruding during a print. For example, if you had 60ml of capacity, instead of manually checking that your print is less than that amount you could set it with a command (similar to having a max X-distance of 200mm). Also, if you had a limit switch then you could reset the syringe plunger back to the full 60ml capacity.

Has anyone used this type of feature or know of a board/firmware that could support it.

Thanks

... I'm using "G92 E" for resetting my paste-dispensers - either as script in a 'custom button' or as file output when manually teaching with the controlling plugin.

All other dispenser specific actions or limits are specially programmed in pronterface for the actual paste-dispensing application ...

Edited 1 time(s). Last edit at 09/28/2015 04:51PM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

As VDX says, G92 E0 is commonly used to reset the extruder when using absolute extruder coordinates.

What might be more useful to you is a switch that causes the printer to pause (and execute the pause macro file) when the syringe is close to running out. I plan to add a facility for a manual pause button to the firmware soon, so you could use that.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
VDX
All other dispenser specific actions or limits are specially programmed in pronterface for the actual paste-dispensing application ...

Does this mean that you are manually inputting limits on the command line? And if so, how would you set an upper limit for the extruder assuming that it has just been set to zero using G92 E0?

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DC42
What might be more useful to you is a switch that causes the printer to pause (and execute the pause macro file) when the syringe is close to running out.

That would be a very useful feature to have and I'm sure I could make use of this in my setup once it is released.

If I were to design my ideal system for syringe based paste extrusion, it would have 2 limit switches: The first switch would be the upper limit, which would be able to set the lower limit (G92 E0) and upper limit (before syringe runs out of paste). The second switch is an idea that would be nice to have but not necessary - a switch that is compressed when the syringe pusher first makes contact with the plunger. When using a new syringe they are not all filled to the same level and it would be nice to automate this process.

Edited 1 time(s). Last edit at 09/28/2015 06:41PM by ca3d.

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ca3d

Quote
VDX
All other dispenser specific actions or limits are specially programmed in pronterface for the actual paste-dispensing application ...

Does this mean that you are manually inputting limits on the command line? And if so, how would you set an upper limit for the extruder assuming that it has just been set to zero using G92 E0?

... I'm partially rewriting pronterface for a paste-dispenser application and either change the functionality/behaviour of pronterface, or include plugins for communication and exchange with other modules or external electronics.

The dispenser is a piezo-driven type, which can be loaded with cartouches, or 'endless' support via an external reservoir.

Here is a product video from the vendor with the dispenser in action:

[www.youtube.com]

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
DC42
I plan to add a facility for a manual pause button to the firmware soon, so you could use that.

I was wondering if this feature was still going to be included in the next firmware update. It seems like a very useful feature that could be implemented into the system in numerous ways.

Thanks for all your hard work improving the reprap fimware and constantly making changes/improvements.