Scroll saw bowl reborn

Good day folks I intend to make the pictured bowl with my GF. It is scroll saw bowl that I have been doing with a 1/16 straight milli on a CNC. Material thickness is 3-5 mm.

2 questions for the group:

Someone who I met once who seemed to know what they were talking about in terms on lasers said:" thin woods tend to curl. I will need to weigh down the corners." This a true concern? GF have some sort of magic pixies that will fix this or look out for me?

And second can the software be programmed with parametrics and loops? I make these bowls on a Biesse CNC with about 10 lines of code. 1999 rover 322, old beast but still kicks butt.

Cheers all!


That is a beautiful bowl!
This may be one situation in which the Glowforge will introduce some new challenges, but may also make things faster in the long run.

Unlike programming it directly for your CNC, you are going to have to generate a vector cut file for each layer of the bowl.
You can absolutely use a parametric CAD program to do this for you since it looks like each layer is different. Have you ever looked at OpenSCAD? You could probably use it to write a script that would blast those out with lots of interesting variations…
If you rotate the layers, do they nest?
If so then you are in for a treat since you will not lose nearly as much wood to kerf.

I don’t know much about if the wood will curl, but I bet with some power/speed experimentation you will be able to figure something out.

First off,

Does not sound like your wood is paper thin, and also segmented, so it should not be an issue.

If you need some cut curves, I could whip up some in Rhino3D in about 30 seconds. A simple polar array of a profile

Question… is this one piece of wood? or is this many slices that have been layered on top of each other? Either way, this is beautiful work.

Yes, this is really cool. I may have to try making something like it when I get mine! Looks like it was all done from one laminated sheet, and then each ring has been rotated 10° so it overlaps the one below, am I close? As others have said, the parametric magic would be done outside the Glowforge software, but remember the other difference is that the laser will burnish the kerfs so they would be very dark. This might actually be a good look too though.

I have never heard of curling with wood, except in slicing layers off of bulk wood.

Since the guy said to weigh down the corners… I am inclined to think that he means large sheets of thin wood tend to be curled/warped. This is true, just due to the weight of the sheet itself. But the Glowforge has a small enough working area, that won’t really be an issue.

So it is not a “When the laser cuts it, the cut pattern curls out” but rather “In order to get the giant sheet of thin wood to lay flat, secure all corners very well”

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as @jkopel said. Its super easy to use some kind of parametric design software to generate the vector files. I don’t have experience with OpenSCAD (should I???) but you can easily do it in Rhino3D with the grasshopper plugin. Grasshopper is free and works with both written script and graphic programming. For people who use Rhino if you haven’t played with grasshopper you should!

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Morning ! It is a single sheet, made with off cuts and such. I make them around 50 cm , which is around 20 inches. It needs to be square, so my pro’s pass through should be perfect. It is rotated 1 notch and stacked. The cut time of 1 mm per pass at 1m/min made for 4 to 6 hour runs. Hoping one pass at whatever this goes at will be faster.

Openscad I’ll look at later, and have not used rhino. Rhino isn’t free I’m guessing? I got one ring done in inkscape using the graphing calculator extension(the name escapes me atm). The problem is that inkscape doesn’t have an AutoCAD style offset, and also doesn’t do loops for repition. All it is is a math equation.

I am learning JavaScript atm(cabinet maker, so not my thing ). What I read is there is a SVG jquery. So I’ll make a lil program and have it make me a vector file.

Here is one more. Cousin’s wedding present. I went back down half way through. I want to experiment with expontial width of layers to one day. (Once I find how to load a pic from my phone to here I’ll add pic…)

. The bigger one is the wedding one, the smaller is another view of previous.


Again these are awesome! Great work!

This link might be of use. It says that Inkscape has an offset and inset feature and explains how to do it. Personally I don’t use Inkscape so I can’t comment more on it. Do you know AutoCAD? If you do and have access to it you can use that. There are many ways of getting AutoCAD files to a laser cutter.

Also you are correct Rhino is not free. Quite expensive actually, I don’t use it just have some experience with it.

Other people have already said it, but what a cool looking piece. Love the geometric pattern with the different wood types.

Can AutoCAD draw parameters ic equations? And then loop through it with a counter ? If so awesome. Solidworks can do the equation drawing bit, but I don’t think it can loop through it. Yes I can offset, but the offseting never seems to work out right. Also in response inkscape and offsets it does, it does do it like AutoCAD as far as I can tell. Such as just specifying a distance and go.

I didn’t think so after reading your questions but then I did some googling. Apparently it has its own scripting language that is capable of looping and counting. Its called AutoLISP - Wiki Article
Here is the User Manual

Never used this but I would be interested in hearing from someone that has.

This is one of the best examples of using digital tools to do things that mere human calculation would be impossible for the average person. Great work and thanks for the excellent pictures. And this forum has led me to explore so many Inkscape and Sketchup plugins. Inkscape has a parametric and a loop plugin. I was thinking about having to code something in Scratch to make nifty whirls a la Spirograph and lo and behold the tools are already there.


Wow. Very cool! You’re on the right track: outputting SVGs is the best way to drive Glowforge from code. As for curling, if the wood has curled, Glowforge can handle it, but it can’t prevent warped wood from being warped. And as you indicate, sometimes cutting relieves stress and causes the material that’s been cut to curve, even though it was straight before. That’s something to talk to your wood supplier about, though.


Here is a link discussing what the Inkscape extension can do and how it can be used for a specific shape. @rpegg will like this one.


These are very beautiful! @kevinmcvey just did a laser thursday project where he used code to generate a bunch of cut files: Algorithmically generated laser design

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Check out OpenSCAD, this is exactly the sort of thing it is designed to do, but beware, it is a pretty complex beast. AutoLISP is a fascinating system, but also has a pretty steep learning curve (and AutoCAD is far from free). I don’t know anything about Inkscape’s scripting (if it has any) but your Javascript idea might just be the fastest/easiest way of all!

There are lots of existing JS drawing engines out there, and many of them allow you to render directly into SVG, like:


Lately I have been playing with P5 ( ) which is a re-write of processing in javascript.


Appreciate all the links!

That’s awesome on the links! Be checking those out. Inkscape extension for parametric curves that the other poster posted to is the extension I used. I need it to do one iteration of the equation, then up one variable , then repeat. The variable is basically the offset.

Sorry to be vague but I sell these, and though I love sharing the ideas , I also don’t want to give the keys to the kingdom all away. Though if someone wants to partner , message me. If that’s possible on these forums.

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