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MH365 plots a wonky path

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I just got an MH365, hooked it up by USB to my laptop running Ubuntu.  It was automatically recognized and added as a printer.

I started inkcut version 2.1.5, the current version for Ubuntu 20, which found the device, but didn't automatically select a driver.  I selected US Cutter Refine MH-721, the one that seemed closest to MH-365.

If I plot an image using inkcut or by sending the HPGL file directly to the printer device, the plotter draws (I have pen and paper in it for now) a somewhat recognizable path but I consistently get the same kind of corruption.  See the image below, where I plotted the file twice.  The HPGL file looks fine in an HPGL viewer.  The HPGL file is also attached here.

The errors seem to be of two kinds:

  • a vertical segment followed by a horizontal segment get combined into one diagonal segment - see the left edge of the letter H, for example
  • an x co-ordinate is drastically incorrect, usually at or near the x origin - see the triangular detours in the circle, for example

 

What is going wrong?

Thanks in advance,
Mike

P.S. Since it's a new machine I'm really trying to determine if it's a problem with the software/file or with the machine itself.  I don't have a windows machine handy to try other plotting software or another plotter to test the HPGL on.  If someone could run this HPGL file on their plotter, or send me a small HPGL file that is known to work on an MH365, that would be a big help.

 

circle.inkcut.hpgl

PXL_20221229_035028794.jpg

Screenshot from 2022-12-29 20-03-26.png

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I had to look up what Ubuntu 20 is.  I don't know of anyone using it here. There is only just a couple handfuls of people that answer questions.  Most all of us members who have been on here for years, use design and cutting softwares compatible for our vinyl cutters. And most use Windows operating system.. I don't know of anyone using INK CUT.   If this cutter was bought from US cutter, then it is only for Windows,(says that on the ad.) and cutting software came with it , for windows.   Some people do get it to run on a Mac sometimes, but with Bootcamp and similar for a Mac.  Your cutter is not a printer and does not set up like a printer. Nor is it plug and play.  . It is a vinyl cutter/plotter.  You must download the FTDI driver, run and install it. Then windows will assign it a com port. 1-4, Then you go into your cutting software set up ,choose your vinyl cutter , and choose the same com port number. They must match.  Pretty easy, Most value cutters all set up the same way.   What is the reason for using Ubuntu 20 and Inkcut. ?

These are the only threads over many years that UBUNTU is ever mentioned and that was many years ago,  maybe something there can help.

https://forum.uscutter.com/index.php?/search/&q=Ubuntu 20

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Mike, go grab an older Dell laptop from ebay for $60 with Win7, and be done with all this nonsense. Run SignBlazer with RedSail as the machine choice in cutter setup. That's the straight answer. Good luck.

 

 

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I made some progress.  I edited the HPGL file to contain a newline (line feed 0x0A) after every semicolon.  I.e. instead of this:

IN;PU958,4935;PD958,4935;PD915,4932;PD916,4724;PD1001,4724;PD1001,4932;

I send this to the plotter:

IN;
PU958,4935;
PD958,4935;
PD915,4932;
PD916,4724;
PD1001,4724;
PD1001,4932;

And now it plots the path perfectly.

I have no idea how or why this works.  Line feed characters are supposed to be ignored in HPGL.  Maybe this extra (ignored) character introduces just enough delay between commands for the embedded CPU to be ready when the next command comes.  So I'm not sure if it's a fault in the plotter but I have an effective work-around.  I have done several paper plots and vinyl cuts and it seems 100% reliable now with this hack.  I will try to add a feature to inkcut to insert this padding character automatically.

I have successfully used other US Cutter plotters with Linux and inkcut before, but with an RS-232 connection, not USB directly into the plotter.  I suspect the problem is not really specific to the MH365 but something about how the plotter's USB interface sends data to the CPU.

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Good for you.

This information is relevant to absolutely none of us, however, and is merely an exercise in back-patting for yourself.

Happy New Year, Mike.

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Good for you.

This information is relevant to absolutely none of us, however, and is merely an exercise in back-patting for yourself.

Happy New Year, Mike.

Way to end the year being a jerk slice. He did exactly what we ask people to do. Come back with results so other people can learn from their experience. Just because Ubuntu is an out of mainstream option is no reason to berate him,  it's pretty cool to see it be functional for technically savvy users. 

ditto - your experience is great help for the rare Ubuntu user that comes along. If you stick around or stop by from time to time you may be able to help others. I appreciate Ubuntu users (tried it myself for a while but am not computer literate enough to work through the issues.) I run on a mach system which in the cutter community is an oddity as well. most do use windows based programs. ArtCut is a nice (free) option and impressive that it is multi-platform compatible. 

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I made some progress.  I edited the HPGL file to contain a newline (line feed 0x0A) after every semicolon.  I.e. instead of this:

IN;PU958,4935;PD958,4935;PD915,4932;PD916,4724;PD1001,4724;PD1001,4932;

I send this to the plotter:

IN;
PU958,4935;
PD958,4935;
PD915,4932;
PD916,4724;
PD1001,4724;
PD1001,4932;

And now it plots the path perfectly.

I have no idea how or why this works.  Line feed characters are supposed to be ignored in HPGL.  Maybe this extra (ignored) character introduces just enough delay between commands for the embedded CPU to be ready when the next command comes.  So I'm not sure if it's a fault in the plotter but I have an effective work-around.  I have done several paper plots and vinyl cuts and it seems 100% reliable now with this hack.  I will try to add a feature to inkcut to insert this padding character automatically.

I have successfully used other US Cutter plotters with Linux and inkcut before, but with an RS-232 connection, not USB directly into the plotter.  I suspect the problem is not really specific to the MH365 but something about how the plotter's USB interface sends data to the CPU.

The USB interface on the MHs is nothing more than a generic USB to serial chip so depending on the driver Ubuntu is using, that could be the source of the problem.

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I made some progress.  I edited the HPGL file to contain a newline (line feed 0x0A) after every semicolon.  I.e. instead of this:

IN;PU958,4935;PD958,4935;PD915,4932;PD916,4724;PD1001,4724;PD1001,4932;

I send this to the plotter:

IN;
PU958,4935;
PD958,4935;
PD915,4932;
PD916,4724;
PD1001,4724;
PD1001,4932;

And now it plots the path perfectly.

I have no idea how or why this works.  Line feed characters are supposed to be ignored in HPGL.  Maybe this extra (ignored) character introduces just enough delay between commands for the embedded CPU to be ready when the next command comes.  So I'm not sure if it's a fault in the plotter but I have an effective work-around.  I have done several paper plots and vinyl cuts and it seems 100% reliable now with this hack.  I will try to add a feature to inkcut to insert this padding character automatically.

I have successfully used other US Cutter plotters with Linux and inkcut before, but with an RS-232 connection, not USB directly into the plotter.  I suspect the problem is not really specific to the MH365 but something about how the plotter's USB interface sends data to the CPU.

It is to do with the two things:

1. Data transfer type (USB Cable/ Serial Adapter): The serial adapter is much reliable and too less prone to errors and data losses during transmissions. I learnt it the hard way after ruining 40 dollars worth of vinyl about 5 years ago and haven't used USB port since then. My advice is either get a laptop or a desktop with just enough programs and keep it permanently hooked to the plotter using serial cable and not USB cable

 

2. Security features of the Ubuntu itself: Almost all the cutters are built up to work well on the windows operating system. Ubuntu/Linux being equipped with many more security features finds most of the cutters struggling to go through

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