Printing via USB

[fredz 3]

If there is a connection fail while writing, your card is ruined ;)As the writing is a lot slower than doing it on the PC, there is a far greater chance of it going wrong.

 

I don't know why you're saying that. If there is a connection failure, the file won't be written or will be corrupt. SD cards don't get "ruined" by anything like this, unless I am mistaken.

Edited January 22, 2016 by Guest

[asb 7]

I don't think it's at all possible to do this. If it is possible, it will probably be very slow and will probably ruin your SD card in record time.

 

If the SD card in the UM2 can be accessed through the USB connection, it will not "ruin your SD card". It's definitely not slow, even with USB2 the card reader in my DSLR is much faster than the built-in card reader in my PC. All digital cameras and many MP3 players work exactly like this. I have read and written hundreds of thousands of files through USB from and to SD cards, and I never have encountered a damaged SD card or a damaged file.

The only question is *if* the hardware in the UM2 is as smart as the components of a MP3 player that costs 1/10th of an UM2. If it is not, the hardware should be enhanced and this would be a feature request for Ultimaker 3.

Edited January 22, 2016 by Guest

[nallath 1,120]

I don't know why you're saying that. If there is a connection failure, the file won't be written or will be corrupt. SD cards don't get "ruined" by anything like this, unless I am mistaken.

 

The file must be written in chunks because the printer simply does not have enough memory. If you are writing to the sd card and it loses connection you can cause permanent damage to it. This is why you should always safely remove SD cards

[fredz 3]

The file must be written in chunks because the printer simply does not have enough memory. If you are writing to the sd card and it loses connection you can cause permanent damage to it. This is why you should always safely remove SD cards

 

We're talking about sending the file, via USB, to the SD card in the printer.

Not sending it to the printer's memory.

When it is completely uploaded to the SD card, it could then print normally, without having to move the SD card. The printer would just need some directory which it "watches", and when a file is completely on the SD, it could start printing.

Would be a good addition and simple te execute.

[erri 2]

It should already be possible to write gcode files over USB to the sdcard and print them afterwards (not tested):

Open a file on sdcard for writing with Gcode "M28 ".

Then send the Gcode file contents.

Close file with "M29".

Start print with "M23" and "M24" or manually at the printer.

Start printing over USB is not possible with the "UltiGcode flavor" but should be possible in "RepRap mode" (Note that i have not tested this).

You can get into trouble with filetransfer/printing over USB because of so called "ESD errors". Normally the operating system (windows, linux) closes the USB device on such an error, so the hostsoftware and/or firmare has no chance to recover from such errors. USB communication will stop.

Some of the ESD errors are generated by the UM2 itself: USB datalines are not shielded on the mainboard, and next to it are wildly laid unshielded wires with high current

stepper and PWM signals.

I have done some experiments with a custom firmware (https://github.com/ErwinRieger/Ultimaker2Marlin-USBPrint) where the file on sdcard is opened in "ReadWrite" mode. This allows the start of the print while still downloading the gcode. So the start of the print doesn't have to wait for the entire transfer. On the other hand, the file acts as a buffer to survive communication interruptions or phases

of high CPU load (on the printer as well as on the host) where not enough data would be sent.

ESD errors are handled through a "reconnect feature" where the host side detects the closed USB device and re-opens it to continue the download/print. But this feature depends on

operating system support (i am using linux, don't know if it's possible under other os'es).

Note that i no longer maintain this firmware. It is working good, but the Mega 2650 CPU reaches its limits when printing fast and with high segment counts. I have therefore switched to a firmware/host software scheme with host side preprocessing to relieve the printer CPU.

[fredz 3]

So this is all good, but how exactly do I print via USB in Cura 15.04.4 (Windows)? I see no button or option...

[gr5 2,170]

I'm not sure if you still can in cura 15.04 - I think it's there somewhere.  Cura is really your worst option.  The least control over feedrate and temp and so on.  Use pronterface:

http://koti.kapsi.fi/~kliment/printrun/

Just copy in the files and run.  No installation necessary.

Edited January 23, 2016 by Guest

[nallath 1,120]

Use printrun. It's way better than what Cura has wrt to usb printing right now.