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View Full Version : E-cut plug-in for Corel Draw: great features, but problem with 'Node extension'...



Ian Stewart-Koster
11-01-2017, 10:03 AM
I've used e-cut for a while and like it.
Especially the 'cassette' or box function for the cnc router, and the nesting is pretty good, too, for lasering. Perimeter is useful, too.

Yesterday I went to use the 'extend nodes' feature in version 6, to make a path to laser around letters where the start and end points are not on the perimeter.
That is a great idea, because it saves you ruining part of a letter with the laser beam while the bottom catches up to the top - eg in 20mm thick acrylic.
Ordinarily I'd set an overlap at about 2/3 of the material thickness, to make sure the cut finished and reaches the start, underneath the substrate.


Anyhow I was trying the 'extend nodes' option in CAD functions in E-cut version 6 or newer.
It was good, BUT... only about half the letters worked.
The other half had the nodes extended INSIDE the letters, instead of outside,
or the ends of the letters were displaced away from their actual position, so that some that should have had a 90 degree corner, now had a 100 degree corner, and an end that stopped nowhere near the start.
Thirdly, when I applied it to some letters with insides like D, or e or R, the inner shape had the extensions onto the letter part, instead of the background.

So, I found it ruined a few letters before I stopped it and thoroughly checked each one...

I was wondering if there is a solution. I had to omit all letters with insides, but it still did not do all outsides well.

Other than that, it is a great idea in the program.
I have emailed the maker to ask him. I thought I;d ask here in case anyne has encountered this, and has a work-around.


Thanks!

Kev Williams
11-01-2017, 2:50 PM
Sounds like you're talking 'tangential entry/exit'- My Casmate's always had it, works great when cutting vinyl with a swivel knife, the knife enters outside the letter, curves into the letter path, and at the exact point in entered the letter path, it exits out, mirror imaging the entry in. With vinyl, this insures a complete cut instead of an uncut 'stencil tab' that makes weeding a pain. Tangential in/out also works great for laser cutting, it reduces the heat at the start and end points- which are the same point...

Where the tangent enters and exits depends on the toolpath direction, CCW is typical of an inside curve surrounded by an outside curve, and CW curves are typically always outside curves.

If the outsides are correct and the insides are wrong, then check to make sure your curves are COMBINED and not just GROUPED, as combining stacks the inners and outers correctly, whereas grouping *may* (not positive on this) make all curves clockwise. When combined, any text that's been converted to curves- not in 'font' format- will paint correctly when combined. When un-combined and painted, EVERYTHING will paint, including the holes. This is the easy way to check. If it paints correctly, it SHOULD tangent-cut correctly.

However, I've found that a lot of graphics people get lazy and just stack white behind black instead of 'nothing' behind black- when this happens, combining can have the opposite effect- or not, depends on how many layer of 'cheat' colors are hiding ;)


Hope that all made sense! :)

Ian Stewart-Koster
11-01-2017, 8:04 PM
Thanks for the reply, Kev.
Yes, I made certain the inner and outer parts of letters were combined. (not just grouped)
I've used Corel since version 2, and that sort of action is second nature!

That's why the whole thing has me scratching my head... also the open-ended nodes...

Ian Stewart-Koster
11-01-2017, 11:45 PM
370817 370818 370819

The first two are in Corel X3, showing some node extensions where they are supposed to be, and some half into the letters,
and the inners of letters that are converted to curves and combined, have their extensions the wrong way,
and the third shot is in the Goldenlaser software, after exporting from Croel as a DXF and importing into Goldenlaser: some nodes have rotated away from their normal end point.

I'm stumped.
I've emailed Pavel about it.
It's still a terrific program!

Ian Stewart-Koster
11-02-2017, 3:31 AM
Interesting times...
I started afresh, and the nodes went into all the right places.
It was just with the 'old' file, that they didn't.
But after doing the DXF export & import into Goldenlaser, some nodes moved, once again.
If I imported the DXF back to Corel, it was OK, so the problem was the chinese program.

BUT... E-cut has a special DXF export option - and when I used that, the nodes did not move.
All was good.
It still doesn't explain whty the first lot went awry...some gremlin somewhere- perhaps a miniscule looped path somewhere...

Kev Williams
11-03-2017, 3:28 PM
Well, I'm no autocad expert so I don't know the difference, but even going back to the early 90's my Casmate has an option to export in 'lines and arcs' or 'polylines'-- some differences I've found:
importing Casmate to Corel, 'lines' imports perfectly. Importing Casmate polylines, everything is broken. So guess who never EXports as polylines? ;)

Corel and Gravostyle have no such options, as it seems the tend to be generic in nature... But I have other issues between the programs, and not just with DXF:
Gravostyle doesn't like importing DXF's unless exported from Gravo. Goofy curves and other anomolies happen. Gravo LOVES EPS files whether from Gravo or Casmate, but customer-sent EPS files usually come in as either just a box with the filename in it, or some or all of the graphics upside down... go figure!
Casmate doesn't import DXF's either, and loves EPS.
Corel doesn't like importing EPS files from either Gravo or Casmate, everything is painted black, and sometimes with sections altered or missing...

My favorite dumb problem is EZcad--
This is screenshot of 2 versions of the exact same graphic,
top is a DXF created by Corel,
bottom is DXF created by Gravostyle..
370935
Bit of a difference? ;) -- yet the Gravo version imports into Corel just fine.

Pretty sure it's a Chinese software thing. All I know for sure is, it's always a crapshoot, and all I can do is find what works and remember it! :D

Ian Stewart-Koster
11-04-2017, 3:51 AM
Yep, Kev... each program has its idiosyncracies...
I've found oddities in exporting & importing fron Enroute too, and this chinese software hates AI files, despite saying they're OK...
You learn a routine that does work, and have to remember to remember what it is for next time you need it- or else it's a one-way street with conversions & imports!