Generic HPGL Vinyl Cutter Post Processor

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dmoore
Vectric Apprentice
Posts: 72
Joined: Tue Jan 22, 2008 4:39 am
Location: Houston, TX

Re: Generic HPGL Vinyl Cutter Post Processor

Post by dmoore »

Holy Smokes! I got it working. So I went out and found a Graphtec FC5100 (48") cutter in great shape for the crazy price of $500 (heck, cheap Chinese cutters are this much in 48"). The plotter "talks" HPGL but when I changed the "UNITS" to "INCHES" it didn't cut correctly, it was cutting very very small. So after some investigation and a review of the Post Processor Guide (http://www.vectric.com/forum/viewtopic.php?f=4&t=6213) and then some work in excel, I discovered if I changed:

VAR FEED_RATE = [F|A||1.0|0.0166]
VAR X_POSITION = [X|A||1.0|400]
VAR Y_POSITION = [Y|A||1.0|400]
VAR X_HOME_POSITION = [XH|A||1.0|400]
VAR Y_HOME_POSITION = [YH|A||1.0|400]
VAR ARC_CENTRE_I_ABS_POSITION = [IA|A||1.0|400]
VAR ARC_CENTRE_J_ABS_POSITION = [JA|A||1.0|400]
VAR ARC_ANGLE = [Angle|A||1.3]

to

VAR FEED_RATE = [F|A||1.0]
VAR X_POSITION = [X|A||1.0|1015]
VAR Y_POSITION = [Y|A||1.0|1015]
VAR X_HOME_POSITION = [XH|A||1.0|1015]
VAR Y_HOME_POSITION = [YH|A||1.0|1015]
VAR ARC_CENTRE_I_ABS_POSITION = [IA|A||1.0|1015]
VAR ARC_CENTRE_J_ABS_POSITION = [JA|A||1.0|1015]
VAR ARC_ANGLE = [Angle|A||1.3]

It now appears to work. I'm not 100% sure that the 1015 multiplier is 100% correct but it appears to be. From what I can tell, the default mutliplier of 40 is against some "constant" of .025, so .025*40 = 1mm or 0.0393701 inches.

Can anyone explain why you have to even put a multiplier in if you change the "UNIT" to inches and why is the "constant" .25?

Otherwise it works great - I can even print directly from VCarve Pro using the "Output Toolpaths" function. I think Vectic is missing the boat by not adding in a few other simple post processors for all those other common cutters (USCutter,p-cut) - because anyone who has used expensive and poorly written applications like Flexi that are cutter specific, understands how nice it is to have one more value add function in Vectric products.

Thanks,
David

dmoore
Vectric Apprentice
Posts: 72
Joined: Tue Jan 22, 2008 4:39 am
Location: Houston, TX

Re: Generic HPGL Vinyl Cutter Post Processor

Post by dmoore »

Ok, I understand why the 40 multiplier is used (from http://en.wikipedia.org/wiki/HPGL):

SC0,40,0,40; allows scaling in millimeters since 1 mm = 40 plotter units. Each user-unit is 1 millimeter, in both X and Y directions
So, the scaling in the post processor to 40 was to make output of 1mm equal the 40 "plotter units". So, I was actually slighly off on the 1015 multiplier, it should be 1016. 1015 is .999016" and 1016 is 1.000001".

So, if you are an inch person, change the UNITS to INCHES and all the references of 40 to 1016 and it should work great with your imperial based cutter/plotter.

Thanks!
David

signmarketingman
Vectric Wizard
Posts: 586
Joined: Sat Jan 08, 2011 12:29 pm
Model of CNC Machine: Professional done home built.
Location: SW Michigan

Re: Generic HPGL Vinyl Cutter Post Processor

Post by signmarketingman »

If I remember right,
There is a resolution setting a well on many cutters. I wonder if setting the resolution if that cutter has such an animal would help your cause..

keith20mm
Posts: 22
Joined: Fri Sep 11, 2009 2:01 pm

Re: Generic HPGL Vinyl Cutter Post Processor

Post by keith20mm »

Old post, but someone will cross this topic again.

A few weeks back, I purchased, for my wife, a 31" Vinyl Express R-Series II from SignWarehouse, a cutter/plotter. This cutter comes with Vinyl Express LXi Expert 12 vector drawing/cutting/plotting software.

This particular software locks to the installed machine, and must be un-installed to move it to another machine, max 5 transfers.

It so happened that she needed to travel this week, and she took her laptop, with the software. It also happened that I needed to cut a pair of fiber washers from gasket material, for a machine I am building.

I wrote a program using Borland C++ Builder 5 to write HPGL to the vinyl cutter to find out the printer's interface. I found the driver online, same as on her distribution CD.

The cutter/plotter data interface is HPGL, ancient, yet functional.

I found in my Aspire 8.5 a post processor for the cutter, so I inspected it to see it use the AA HPGL command. This particular plotter apparently ignores AA.

Great, I found that Bart had written a post processor to make HPGL code using only X/Y, no arc commands.

In my test C++ program, I ran a CI circle command which didn't draw a circle.

I don't know what all HPGL commands this plotter does respond to, but it appears to ignore AA and CI. However, X/Y is sufficient, for now, and I cut my fiber washers, using the inch conversion version of Bart's post processor, which is a slight variation of 'dmoore' s post, using 1016 divisions per inch, instead of 1015.

This plotter appears on the market as:

RedsailCNC.com RS800C
redsail.com.au
SignWarehouse.com R-Series II
SignMax.us
and probably many others, all from the same factory, in various widths.

All appearing the same except for the name decal.

As to capability, quite pleased. She has gone nuts making vinyl stick-ons for all kinds of things, and sandblasting glass plates, T-shirt screen prints using cutouts for friskets, etc, using the LXI software.

Now that Bart and dmoore have worked out VCarve/Aspire post processor, I'll be able to use the cutter, using the familiar interface in Aspire.

Thanks, Bart and dmoore, I really appreciate ya'll getting that done up nicely.

As Bart had requested, any others going to a vinyl cutter with VCarve or Aspire, please do post your results.

keith

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