Question about software: contour cuts?

qa

#1

Maybe this has been covered in your demos but I didn’t see it. When you put a hand drawn item in the Glowforge for cutting, is there a setting within the software that allows you to specify a border around the contour cut? This is a common feature in vinyl cutters and hobby paper cutters for example. This would typically be a 1-3 mm border (user selectable) of white space left around the periphery of the item rather than cutting right up to the edge of the drawn line. I can imagine uses where you would want to engrave the drawn lines but expand the cut border. Does this make sense?


#2

That’s a good question. So drawing with a Sharpie on the material gives a cut line. Does it leave the mark and trace outside edge or does it pick the middle of the line and split the difference. Can you set it to cut or engrave a certain distance from the edge of the line? From what I understand a software vector line has no width even is it is 3 pixels wide. What about drawn lines?
Check out this video at 5:10:


#3

I was curious about this as well, and at the recent open house, and watched the process carefully. The software seems to do several things in order to make this hand draw/then cut thing work.

  1. It was clearly doing a little clean up by simplifying the drawn shape to define a cut line.
  2. It seemed to keep close to the full detail of the internal lines.

My guess is that it is a canned process at the moment, so they can just point and shoot for demos.
I would image a number of ways that you could introduce variables in the future.
For instance, you might be able to define how tightly you would like the cut line to adhere to the drawing (i.e. how much simplification or point removal it would do). Another might be to create an offset line as @cynd11 suggests.

Here is a close up of the silly doodle I drew and had cut out for me at the open house. You can pretty clearly see where it decided to cut the outline. I expect that when the software is “final” (that never really happens) and it is not a prototype machine that the resolution would be better since you can see the raster engraving lines pretty clearly as well.

(open the image in a new tab for the full resolution version)


#4

Dan has mentioned in previous post that the user can select whether you want the inside, outside, or the middle of a hand drawn line to be where it cuts.

Edit: Found Dan’s actual response:


#5

Thanks for posting the link to answer the question. I had missed that post before. Need to remind myself to search first with different terms. Especially have to go back to the earlier forum posts before I joined. It seems that new questions have already been addressed at the outset… I have been tempted to transcribe a few videos just to document some things. Really wasting a lot of time filling up the wait with endless rabbit holes: spent a couple hours researching leather and leather suppliers.


#6

Thanks for finding that!

This confuses me though since I am not sure how a magic wand (i.e. select contiguous fill) would enable you to make a cut line on, for instance, a solid shape.

I guess we will just have to wait and see…


#7

(I’m going to geek out a bit on how it works right now, but we will likely make a lot of changes in the future…)

So the original code, used for the very first Tested.com demo with the scary looking uncased prototype, assumed everything black was a line. It found the center, and ran a cut down the middle of it. This was very useful for cutting boards in half but not so much else, and the code did not have a happy time with n-way corners where n>2.

Since then, @Dean and @Tony came up with a much more sophisticated approach.

First you crop the image. Right now it only supports a rectangular crop. Ideally you kill the background grate with that so you just have the roughly black-and-white surface.

Second, the software silently separates the image into black and white. It will engrave the black, and ignore the white.

Last is an optional step: if you click the magic wand in a white area, it will put a cutline around it. The most common case is to click outside your image, so it cuts out the inside of your image from the border. The “magic wand” finds all contiguous white areas, then puts a path around them for the cut. That lets you make a hole in the middle of your donut.

I have to tell you… the results of this are crude, sloppy, and limited. And amazing. It is absolutely magical, and I can play with it forever. Kids, grownups, everyone loves it. And we’re only just starting to touch the surface - at the open house, @Kusmeroglu actually drew little stands as well for her design and cut them out, to create something that was legitimately 3d.

Look, if you want to get fancy, you can flatbed scan your drawing, vectorize in Inkscape and Illustrator, and go nuts. But for quick and delightful, I gotta say, Tony and Dean nailed it.


#8

Excellent!
The best solutions are the ones that seem obvious once explained.
I wish I had not been in such a hurry during the open house (I had to bail early) since I was really enjoying watching how excited everyone was to get their demos cut.


#9

I do a lot of leather work and the best place I have found for leather is Springfield leather company … they have a nice website and I have been doing business with them for several years. There is a place to ask the owner questions and I found out that they use a laser cutter to cut some of there leather. I was told that veg tan is pretty consistent but the other leather was a guessing game and I have also read that the chromium cured leather can give off some pretty harmful fumes. I mainly use veg tan myself . My plan is to make all of my patterns digital so I can save time just cutting them on demand with the gf.


#10

I should search for where he said it, but I am hoping I can be lazy since Dan has his eyes on the post already after replying (if his settings for forum are default).

Dan said once elsewhere that you can translate and scale your images after the Forge takes the initial image. So if you do not translate at all, and scale the outline cut slightly larger… that gets you the border around your initial image that the OP was asking about.


#11

Thanks everybody! I have a better idea of how things work (I mean, will work) now.


#12

I try to scan every single post in the forum, at least quickly.

Vegetable tanned is the stuff! Highly recommended. Better/faster than the pretreated.

Yes, you can translate and scale after you scan!