Printing with USB port ?
Hello,
I am trying to print directly via USB. The exercise is necessary for me to be able to order later a small print farm from a single computer. I use Pronterface for computer / printer communication.
What's going well:
1. Print Prusa's test files from its SD card;
2. Connect to the printer through the port /dev/tty.usbmodem1A21; messages are displayed simultaneously in Prontface and on the printer control screen;
3. The preheating control of the nozzle and the print bed;
4. Loading and viewing the object to print after importing its file;
5. When sent for printing, the print head does its 9 "z" point tests on the print platen; the messages in the "Settings / debug communications" menu indicate that the printer receives the first GCode commands perfectly;
6. The print head makes its first trace in the bottom of the tray to "purge" the PLA from its nozzle ...
What's wrong:
7. The head draws a first line, then stops;
8. The "debug communications" shows a continuation of "The progress should be updated on the printer now: M117 0.03% Is 10:46:48" but nothing else is out ...
My environment:
- Apple Mac OS X El Capitan (not possible to evolve higher)
- Prusa i3 MK3
- Firmware prusa3d_fw_3_5_1_MK3
- Pronterface by Printrun version 18 Nov 2017 for mac [/ i]
I said that I disabled the options of the hibernation of the DD, the screen, Pronterface and Slice3r PE ("Nap App" checked).
Attached is a screenshot in standby state, which shows at what stage of printing the print is freezing ...
My questions:
1. Is this due to a limitation of the printer buffer ?
2. Does the computer only send a packet of data once, and the buffer only handles the amount of data it can receive ?
3. What system is used for a print farm ?
Thank you in advance for your help !
Re: Printing with USB port ?
you may need to check with support for compatability for el cap, pronterface hasn't been updated in quite a while from what their site shows.
I would guess they use sdcards on the farm as its the most reliable option.
Re: Printing with USB port ?
There are other programs besides Pronterface that can print via USB port. Cura is probably the most commonly used one (its screen for printer control emulates Pronterface).
To answer your questions:
1) The printer does have a buffer for commands of a finite size; this can be implementation specific, but is usually on the order of 10 - 20 commands.
2) There has to be a "handshake" between the printer and the computer to tell the computer when the printer's command buffer is full, and then when the printer is "ready" for another command.
3) As you can observe in your log file, the "handshake" consists of an "OK" response from the printer. The computer sends commands at full speed until there is no "OK" returned; then it waits for an "OK" before sending another command (the printer only sends "OK" when it has room for at least one more command).
Perhaps your computer isn't waiting long enough for a response, and it decides that the communication link is bad. I notice that you have three error messages all stacked up within the same second. If that is the problem, it may be something that you have to configure outside of Pronterface. Some commands can take a long time to process. For example, if your buffer is full and the currently executing command is a straight line move of 200mm at 20mm/s it will take 10 seconds between the last "OK" and the next one.