auto-print with just a "start" button?

I only have experience with pc based 3d printers, but now I want a simple one without a PC. (i.e. very small, with no user interface required.) I want to set it up so it only makes one or two different parts, so I can flip a selector switch (or maybe swap out an SD card), and hit a start button and it prints the selected part. Can anybody recommend a controller setup that is capable of that?

Thanks!

Edited 1 time(s). Last edit at 10/03/2017 03:56PM by Tenaja.

You can configure smoothie to have a physical switch (io pin) play a g-code file.

[smoothieware.org]
[smoothieware.org]

You might want to confirm that it will work on their discussion group first though, I've found that switch is reliable with simple commands but can sometimes behave unexpectedly. For example I'm not sure what would happen if the button were to be pressed while a print is ongoing.

The other option is have an arduino or other simple microcontroller send the play command over serial. This would likely work with most/all controllers.

Edited 2 time(s). Last edit at 10/03/2017 04:29PM by 691175002.

RepRapFirmware on the Duets can do this. You can put gcode macro files on the SD card to do the tasks you want, and connect buttons to the controller that trigger the macro files.

However, 3D printers are rarely 100% reliable, so IMO you need at least the ability to pause, cancel and restart a print. Also to handle common tasks such as changing filament. So I suggest an LCD control panel. In RRF you can also set up macro files that appear as buttons on the touch screen. So you can create a macro file for each common task.

In the event that you have problems and you find you need to do something different, the touch screen also gives you full control. It even provides a touch keypad so that you can enter arbitrary gcode commands. So you can do complicated stuff without a PC as well if you need to.

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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].

Thanks, you two, for providing insight. I am making tiny parts, so I am not convinced I need to be concerned with pause--can they both perform pause?

Can both of those control systems use an input button to tell them to go find the Home switch?

What are the maximum steps/second they can do?

I am looking for a "set-it-up-once-and-forget-it" solution. Normally, I would just do this with a PIC, but if I can get it going with g-code, it may be easier setup.

RepRapFirmware supports pause/resume/cancel - are there any firmwares that don't? You can trigger these and anything else (e.g. homing) from buttons connected to spare endstop inputs.

The Duet WiFi/Ethernet without the expansion board have 7 endstop inputs, so in a typical setup with 3 endstop switches you can add 4 buttons. Maximum step rate is 380kHz with just one motor moving, and 180kHz to three motors simultaneously.

As you are a programmer, instead of using switches as the user interface, you might wish to use the optional touch screen and program a much reduced UI on it. I am assuming that you want to set this up so that less knowledgeable people can use it and don't have access to all the usual functions; otherwise you could use the touch screen as it comes.

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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].