Poor toolpaths & cycle time

From conversations while it was being developed… tool paths are optimized to use the hottest flame possible to cut through cleanly with minimal kerf, but without burning your wood to a cinder or melting your acrylic into slag. What that means is that sometimes it is taking the beam to a different section to work on something else and let the previous area cool a bit. If you’ve got a lot of paths too close together in your design, you’ll see this happen more frequently. (Happens a lot in some of my designs, and not at all in others.)

My recommendation for happiness all around?..Learn to live with it. It has a purpose. :slightly_smiling_face:

If your squares are really out of square, that first link that @AhnoldZ posted gives the instructions for fixing it. You can have a slight kerf profile effect too though, that can make it difficult to flip something and fit it back in the hole - particularly on thicker materials where it’s more pronounced. So that might be playing in too. Best way to check for square is with a metal T-square if you have one. :slightly_smiling_face:

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@Jules, I know you’ve said this a few times, but I don’t believe it for a minute. I think their grouping algorithm completely messes things up.

I’ve said it before that a really, really easy fix would be check at the end of each line, where the two ends of the next line are. Find whether the start or finish of the line is nearest and cut the line in reverse if the finish is closest. That alone would make a good difference on my worst offending items and anywhere with repeating items/cuts

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Chuckle! Well, I wouldn’t want to challenge your belief system. :wink:
(I wouldn’t expect it to change any time soon though.)

They’ll no doubt add the request to the hopper, so in either case, it’s covered. :slightly_smiling_face:

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sorry jules that didnt quite read how i meant it… :smile:

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if it is what it does - it doesnt do it very well…

ROFL! No worries! :smile:

I can’t get too upset about it…it adds a couple minutes of travel time to each job, but unless you’re running job after job after job…it doesn’t amount to much. A minute or two on a 45 minute job isn’t going to break me.

The killer for time taken is engraving, and you can dramatically cut that time down by two things…orient the longest engraves horizontally, to cut down on vertical travel time, and don’t use really high LPI values. Perfect medium engrave coverage is obtained at from 195-225 LPI. Everything higher will burn darker and cut deeper, but doesn’t gain you anything in terms of coverage. You can get the darker effect if you still want it by decreasing the speed just about 5 points and defocusing the engrave by adding 0.10 inch. (Keeps it shallow so you don’t burn through.)

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That clears up the weird order of ops .
In my opinion there should be different ways of generating these toolpaths though. maybe with some custom settings? I sometimes feel like i’ve bought an apple product :wink: easy to use but nothing really indepth. which is fine! but some options could be easily added for more advanced users without overwhelming the newer ones.

I’m just rambling at this point
thx for the replies, Appreciate it!

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They’re there, it usually just takes folks a while to stumble over them. :slightly_smiling_face:

You can set the order of operations for instance in two ways…the easiest is to drag and drop the thumbnails in the order that you want them to process…that column in the GFUI processes operations from top down.

Or you can actually create them that way in the design. Engraves will show up first, but you can order your cuts by giving them different colors and using the hierarchy of color discussed in this thread:

If you’re doing your own designs, it’s incredibly simple to just set your files up to process the way you want them to.

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at least the GF separates engraves into groups. There are systems where if you’ve got engraves 8 or 10 inches apart, instead of doing them separately they run the entire line back & forth even though for 3/4 of the time it’s not lasering (think a box shape on either end of the bed and nothing in between - systems that don’t engrave by object like the GF are wasting an incredile amount of head movement time).

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Yep. Very dot matrix. (And probably half the people reading that won’t understand the reference.) :smile:

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We’d like to have you try a few troubleshooting steps for us:

  1. Turn off your Glowforge.
  2. Check for small pieces of debris or dust.
  • Check the lower door to make sure it closes all the way. It may require some force to open, but open it, wipe any dust off the edges, and close it all the way.
  • Remove the tray and clean any dust or debris from the surface underneath. Pay careful attention to remove all debris from the four dimples where the tray rests.
  • Check the lid to make sure it closes all the way. Small particles of material, such as dust or debris, can prevent it from closing completely.
  1. Check the surface your Glowforge is on to make sure it’s flat. Ensure it is not twisted slightly and that there is no debris propping up one side of the machine.
  2. Turn your Glowforge back on.
  3. We included an extra piece of Proofgrade Draftboard with your materials shipment for troubleshooting. Place the Proofgrade Draftboard in the center of the bed and print the Gift of Good Measure using the default settings.
  4. When the print finishes, leave the lid closed and wait until the fans stop and the picture updates. Without moving your artwork or your material, take a screenshot of the Workspace to show us the difference between the artwork placement and the actual print placement. Make sure to include the rulers in your screenshot and show as much of the bed as possible.
  • Mac: Press Shift-Command-4 and click and drag a box around your image. You’ll find the screenshot file saved on your desktop.
  • Windows: Click on the Start Menu and type “snipping tool”. Open the Snipping Tool > New then click and drag a box around your image. Click the Save icon and name and save your file.
  1. Send us the screenshot, a photo of the print, along with the date and time of the print, and we’ll investigate.

Thanks in advance!

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I’ll do this asap thanks!

I know about the manual mode of the colors and the drag & drop method :wink: But when you have a large engrave job it’s going to get reallyy messy doing it all manually and after spending this time on getting everthing dialed in what happens when you update your svg and re-upload it? You gotta do it all over again :wink:

Doesn’t sound like you’re ever tried to build a complex interface for a large audience. Trust me when I say that nothing about it is easy.

Go make a custom cut file of ten parallel 1" lines that are placed about a mm apart. Color code them all differently. Go in the the GF UI and order them so you cut them in acrylic sequentially, one right after another, in order.

IF you don’t set the material on fire, you’ll get major sag. Either way, your beliefs will be changed.

Similarly do that to hardwood. Enjoy your new charcoal.

To quote NDGT… The good thing about science is that it’s true whether or not you believe in it.

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I have no idea about the current tool pathing creating instructions to avoid close cuts in succession. I would be surprised if that was the case - but I’ve been surprised before.

We have had Dan say that it doesn’t make a huge difference overall.

You can manually reverse paths to create a more efficient cut order. I did that in this post

For 534 inches of cutting, I saved about 1 minute by optimizing the cut paths - probably less savings than it took to reverse the paths.

In the long run, cutting the same project many times, you would see a cumulative savings in time. For a one-off project, not so much.

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Oh I don’t argue that over heating is an issue - I argue that the GF ordering does not work if this is what it is trying to fix.

I have just created an SVG with 20 lines 20mm long and spaced 1mm apart and printed to Medium acrylic.

The cut order runs exactly left to right - no jumping about - so that’s everything over heated if that was the problem. But it gets better!

The first line is cut from top to bottom, the remaining lines are cut bottom to top - instead of alternating the line direction for a much faster cut.

So I contend two things:

(1) The GF software does not optimise for speed of cutting - and there are a couple of really simple changes to the algorithm which could make a big difference.

(2) The GF software is not ordering cuts to avoid sag or burn either.

1: Agree except for “big” savings. I suspect that it isn’t that much of a savings. (Because the Dan himself said so directly. A troupe of GF staffers with a fulltime focus on the GF says that optimization isn’t worth it, I tend to believe them over my gut feelings.)

2: You may be right, but all I said was that overheating was a real issue and you should be aware of it, so we agree. See option #1, “why?” doesn’t matter so much if they’re being honest about the time savings, and I have no reason to suspect there’s a conspiracy afoot to keep my Glowforge down.

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Please see my post above yours, and the link.

534 inches of cutting, with optimized back and forth paths, I saved a total of one minute. I wouldn’t consider that a “big difference” - just “a difference.”

Hypotheticals and theory are one thing, but I’d say the proof is in the pudding on real-world cutting situations.

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I’ve got 20 minute jobs that I’ve shaved up to 5 minutes by optimising - but to be honest it is such a pain to do by hand and then the GF will ignore it.

I agree, the benefit is small(ish), but it bugs me on two counts. (1) I keep saying over and over again - there is a really trivial fix that would make a significant difference and (2) it really bugs my OCD tendencies that the thing cuts in random places, in random orders and in random directions!!!

I guess it doesn’t matter much to me because it’s just a hobby and have all the time in the world when I’m making stuff but I have seen the Glowforge make some pretty unexplainable moves. One that comes to mind was a project that had words on the left, middle and right sides of the sheet (one engrave file with one color) The machine engraved the left side and the right side together making the head move the complete width of the page and skipped the middle text as the head was traversing over it, only to go back and engrave the middle text afterward. There was no logic to the plan. If it was about over heating I would argue that there was more overheating when it had to go back to do the middle words separately.