USB stalling

Hi I've checked this forum and Google but can't find anthing on this other than the obvious.

I was wondering if anyone has experienced stalling on prints when printing via USB?

It happens on whatever I try to print, from simple objects like cubes to to more complex objects like tree frogs. It happens on curved corners a lot (due to there being lots of small movements I guess) and gradually slows the print down to a complete stop. I've even noticed on infills when changing direction. It's almost as if the printer can't read the code quickly enough.

I've tried on OS X and Windows with exactly the same issue on both, I've tried different usb cables with no change and tried increasing the buffer size in repetier-host too but this doesn't make any difference either.

I'm using DC42 v0.78t.

Any suggestions would be greatly appreciated.

Many Thanks in advance!

Two suggestions:

1. If possible, set Repetier host to not wait for commands to be acknowledged. Sorry, I don't know how to do this. To do it in Pronterface, it used to be necessary to apply a patch, but I think it is now a configurable option.

2. Don't print directly over USB. Even when using the web interface, which in my fork is faster than USB, there are situations in which the data rate can't keep up with the printer. That's one of the reasons why I removed the direct web print button on my fork of the web interface and replaced it by an Upload & Print button. If you really want to stick to using the USB interface then I suggest you use it to upload the file to the SD card and print from there. But I suggest you also try the web interface.

Edited 1 time(s). Last edit at 10/27/2014 07:19PM by dc42.

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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 Dave,

Yes in Repetier-host that setting is called Ping-pong and it's already disabled. It's no big deal really I just wanted to make sure I wasn't doing anything obviously wrong and also thought as this hasn't been mentioned before that other people might be interested.

The web interface works really well it's just different to what I'm used to.

Would changing the baudrate to 250000 make any difference? I can compile the code in eclipse so should be an easy test.

I already have my PC set to use 250k baud. I don't believe the baud rate setting makes any difference (unless it affects Repetier), because on the Duet there is no serial link involved.

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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].

You could try printing over USB using Pronterface - use our latest version here: [github.com] and run ormerod.cmd to set it up correctly for Ormerod. I've had problems in the past printing from Repetier host from Mac, as the gcode progress preview, coupled with going into a screen saver, caused it to choke! Running Pronterface would at least show if the problem is the PC or the serial comms. It may just be that the gcode has many particularly short moves, and the serial comms just can't keep up.

Our instructions do say to print from the SD card - it also means you don't lose the print when the power saving kicks in, or any other USB connection issue occurs!

Ian
RepRapPro tech support

Thanks Ian,
I'll give it a go and report back.

Are there any plans to improve serial comms in the future? as I found this on the RepRapPro site

"You may have noticed that, so far, all printing is done from the SD card. This is the preferred way of printing. It is possible to print directly from Pronterface (ie load gcode files into Pronterface and press print), but the serial communication is slow. The printer will pause a lot during printing, and the printed part will not be of good quality. "

or is the Pronterface update the fix?


Riz

The Pronterface update helps a lot, but can't overcome the limitation in speed of the interface, ultimately.

Ian
RepRapPro tech support

Understood!
Just so you're aware it has helped a lot. I've been testing it this morning. the upload to SD function is really handy too. I'll probably do that from now on just to be safe.

Thanks for everyones help on this!