PDA

View Full Version : Combing objects to eliminate shared edges



Jake Vander Ende
04-22-2015, 4:19 PM
Greetings, forumites. I've been a lurker for a while, having gotten my laser a year ago, but the time has come where I need to post because I need your help. It turns out most people who use Illustrator or CorelDraw don't use them to generate machine paths, so the appearance of a project matters far more than how it was constructed. We all know that's not the case, so we end up with specialized knowledge about how to build files.

Anyway, I've reached the borders of my knowledge and I'm hoping someone here can help.

I designed a game called Breaker Blocks that's played with tiles that are about 1"x1". These tiles are rounded corner squares with varying dovetail tabs. I cut player tiles in 3x3 squares (two sets of 3x3 for one color and 2 for the second color) and I cut a 4x6 area of 24 squares in a third color. From a technical standpoint, the game is designed to waste as little acrylic as possible, so all of the sets are supposed to take advantage of shared edges to save acrylic and cutting time.

To show you what I mean, here's a PNG of a single player tile sheet. I'm new to the forum, so please let me know if that's unviewable or too small for anyone.

312059

You can see that it ends up being a huge sheet that's 4x8 sets of 3x3 tiles, for a total of 288 squares. Seeing why getting shared lines to work appropriately should be pretty clear.

I designed it in Illustrator CS 5.5 by starting with one square, making the first 3x3 set, and then adding the tabs where they needed to go. I used Shape Builder to turn that into 9 individual objects and I added a layer in front for the tile artwork. I copied the set to make 4 rows of 3x3 sets, then copied that column to make 8 total columns. I know the cutting and shared lines work as individual tiles, sets of 3x3, and single columns of four sets, but the problems happen when I do a full page.

My process involves making designs in Illustrator on OSX, then opening them in CorelDraw X6 on Windows 7 via Parallels since I'm using an Epilog Zing24 that doesn't have OSX drivers.

When I generated the shared lines, I used the Pathfinder > Outline tool in Illustrator. That was the only process the removed redundant paths for me, but the problem is that it generated TONS of independent objects. Each corner, each face of each square, and each tab became its own object, sending my total to over 3,000 cutting objects and several hundred raster objects.

When I cut, everything rasters just fine but my machine is omitting cuts seemingly at random. It just skips over them like they're not there. Epilog has been extremely slow in getting back to me, but in the little dialogue we have had they seem to think there's a memory error from there being too many objects.

Yesterday I found limited success by grouping cutting objects in one group and raster objects in another group, then opening the file in CorelDraw X6 and doing Ungroup > Weld for each group. This left me with two objects, which worked once. When I did Reset > Go after the first job to cut a second sheet, the same kinds of cutting omissions happened again.

I'm at a loss here. I've wasted so much acrylic and so much time, yet I'm no closer to figuring out what the problem is, never mind how to fix it. ANY insight would be greatly appreciated, since this isn't even going to be a one-time thing. I have several jobs like this to do and mastering the process is critical.

Thank you for your help. I'm confident that if any place anywhere on the internet has a solution for me, this is going to be it.

Doug Griffith
04-22-2015, 4:32 PM
There are tricks in Illustrator to make removing overlapping lines easier but it's usually still a little work. Since the tiles are symmetrical, why not just create a layer above the tiles, and create new vertical and horizontal lines on top of the existing ones but across the whole sheet. Like tic-tac-toe. Then just delete all the overlapping squares. This will cut a heck of a lot faster than many small lines. Plus you can run the horizontal first as a zig-zag, then the vertical the same way. Very little traversing that way.

Matt McCoy
04-22-2015, 6:27 PM
If I follow correctly, I would just use the Direct Selection Arrow (white) to click the redundant line(s) and then hit delete which exposes the line beneath it. It should look thinner.

Dave Sheldrake
04-22-2015, 6:30 PM
Save as a DXF file
Download Draftsite (its free)
Load DXF file
Type "Overkill"

job done

Doug Griffith
04-22-2015, 8:32 PM
If I follow correctly, I would just use the Direct Selection Arrow (white) to click the redundant line(s) and then hit delete which exposes the line beneath it. It should look thinner.

This is the quick way until there's hundreds of overlaps. If you go this route, make all lines a couple points thick and change transparency to around 30%. Then delete the darker lines. Afterwards, remove stray points by Object:Path:Clean Up. Go back to hairline at 100% opacity.

Matt McCoy
04-22-2015, 9:26 PM
This is the quick way until there's hundreds of overlaps. If you go this route, make all lines a couple points thick and change transparency to around 30%. Then delete the darker lines. Afterwards, remove stray points by Object:Path:Clean Up. Go back to hairline at 100% opacity.

Good tip! I've gone that route too.

Jake Vander Ende
04-22-2015, 9:26 PM
This is the quick way until there's hundreds of overlaps. If you go this route, make all lines a couple points thick and change transparency to around 30%. Then delete the darker lines. Afterwards, remove stray points by Object:Path:Clean Up. Go back to hairline at 100% opacity.

In this case there are about 3,000 overlaps.

I'm trying a method the Epilog rep told me today, which was to use the Combine button in CorelDraw. It seems to work for cutting paths, at least so far, but less well for art to be engraved.

It may actually be a hardware problem, with the data for the print job getting corrupted in the USB transfer from desktop to machine. Even if the job works the first time, it may be corrupting on repeats through the control board. It's kind of comforting to know I'm not going completely crazy, but it's also very frustrating that the job has had this many errors so far.

Thanks for the suggestions, all. If the Combine method doesn't work, I'm going to try out DraftSight next. I have it downloaded and ready to go.

Doug Griffith
04-22-2015, 10:01 PM
Do each of the squares have round corners?

Howard Garner
04-22-2015, 10:05 PM
Assuming that the dark lines and numbered circles are raster and the light lines are the cut lines.

In Corel, I would do it this way.
Move the raster images to a 2nd separate layer.
On a new 3rd layer - over draw all the cut lines with long lines up and down the sheet.
Then only set the 2nd and 3rd layers to the laser.

Doug Griffith
04-22-2015, 10:12 PM
If there are no round corners, I'd do the tic-tac-toe thing with the notches on another layer. It wouldn't take long to separate them.

Mike Lysov
04-22-2015, 10:22 PM
If you use create a table command instead of using squares you will get what you need without removing any duplicate lines. I do not know if Illustrator has it but I do not see why they have not built it in if Corel Draw has.

In Corel Draw when you use it you will get a table object but you can convert it to curves and combine if needed. Then tell your laser to cut inside lines first and it should work.

Jake Vander Ende
04-23-2015, 1:17 PM
Yeah, everything is rounded corners. If it weren't, splitting into horizontals and verticals would make a lot of sense.

I tried the combine process in CD and it didn't do the trick. The laser still managed to skip some sections. Epilog tech thinks that it's data loss from computer to machine, perhaps caused by using a 10' USB cable instead of a shorter cable or an ethernet cord.

I think I'm going to go back, rebuild the original 3x3 manually as one object, and then use that rebuilt object to make the full sheet. There will still be redundant edges between squares, but I think that's passable if it means hundreds fewer objects.

Ugh, what a headache.

Brian Leavitt
04-23-2015, 2:54 PM
Epilog tech thinks that it's data loss from computer to machine, perhaps caused by using a 10' USB cable instead of a shorter cable or an ethernet cord.
Could very well be the case. I had the same problem on my Universals and using signal-boosting (repeater) USB cables solved it.

Matt McCoy
04-23-2015, 2:56 PM
...Epilog tech thinks that it's data loss from computer to machine, perhaps caused by using a 10' USB cable instead of a shorter cable or an ethernet cord...

That's quick and easy to test.

Jake Vander Ende
04-28-2015, 1:59 AM
Yep, it was bad cables. I found a replacement cable that's maybe 4' or so instead of 10' and it does the trick. I guess the cable was just going bad.

It wasn't even file construction at all. I went back to an old, reliable file for a totally unrelated job and I started to find that even it was getting omitted cuts. I know for certain that file is fine and has maybe 200 objects in it total, which is well within the realm of reason. Replacing the cable made that job work again and it also solved the vastly more complicated file.

It's good to know that Pathfinder > Outline is still the way to go for overall overlap simplicity, though not necessarily the best route for machine path efficiency. Thank you for your help, all.