mditto

I got an MH-365 to work with a direct USB connection to Linux and inkcut. On Ubuntu 20 it's plug and play at least in that the device is automatically added as a printer and you can send HPGL files to it using `lp`. But the plotter seems to lose some commands when a direct USB connection is used. I had to modify the HPGL output by inkcut a little bit to make it work. I have submitted a fix to the inkcut maintainer so that a future release may generate output that works. See https://github.com/inkcut/inkcut/issues/367. You can use the existing MH-721 "device driver" in inkcut with other MH models; the only difference is the width and you can set that manually (to 11 inches for MH-365) when you add the device.

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.

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