How to accurately scale a cut?


#1

I just got my Glowforge, and I’m trying to make a few things. After I load an SVG file into app.glowforge.com, I would like to scale it to exact dimensions or at least use the natural dimensions from the file. The best I have been able to do so far is to scale the bounding box against the ruler in the UI, but this is not an acceptable solution. There must be some way to do this, but I can’t find it. How can it be done?


#2

Scaling to exact dimensions can’t be done in the UI.

The natural size is going to depend on how the file is set up as an SVG and if it uses proper units in the file.

Do you have vector editing software? One trick there is set up a proper 20x12 artboard and the UI will respect both the absolute positioning and size of elements.


#3

Yes - we recommend preparing the software (including resizing) in your favorite software before uploading. The few editing tools in the UI are for quick tweaks, not precision work.


#4

Another way is to create a cut outline of absolute value. Then size the item to the outline. I have recently made 4X6 cut SVG at http://www.drawsvg.org/. I use that to size some photos for engraving, then cut them out.


#5

@dan Seems like it would be pretty trivial to have scale, rotate, and position be text entry options along with the other settings in the side bar for each item in the design. You already allow the user to scale, rotate and drag the item around, so it’s not even a new feature really, just exposing the internal numbers to text entry. Most you would need is some basic math to “convert” the values to something user friendly like percentage for scale, degrees for rotation, and inches/millimeters for positions.

I would hope this is in “the hopper” at least.


#6

Indeed it is.


#7

Thanks for the quick replies everyone. Sounds like this is possible, but I’m not quite there yet. More info: I’m using Affinity Designer to create and edit SVG files. I was previously using an artboard size of 8.5x11" when exporting (just happened to be the default), so I started experimenting. It turns out that the artboard size during export affects the size at which the curves are imported. 20"x12" seems close to accurate, but when I export a shape that is exactly 1" wide from Affinity Designer at that document size, it appears to be imported slightly wider than 1" in the Glowforge software. Is there a different artboard size I need to be using?


#8

I know for certain that @Xabbess uses Affinity Designer, so maybe she can help.


#9

(@endotronic) She actually posted about this problem at one time with Affinity Designer. I really don’t know what the solution was though.

https://community.glowforge.com/t/i-did-a-search/9054/20?source_topic_id=13050

I saw something down below where she mentioned Rescale and wasn’t sure if that was checked. Until she can chime in (it’s late!), maybe something in that thread can help?


#10

Oh believe me, I’ve been hounding them for this since day 1. I feel it is of the utmost importance.


#11

Starting with a 20x12 artboard is the key to success in Affinity Designer, as is making sure responsive/resize is unchecked in the export options. HTH.


#12

What is an artboard? Is it just the size that gets put at the beginning of the SVG file?

Does that mean units have to be inches or can it be a metric equivalent?


#13

Art board is essentially a canvas.

If you create a canvas that matches the exact size of the bed, all of the design elements will be placed on the bed precisely where they are in the design.


#14

Yep, make sure “Responsive” is unchecked. I just figured that out in Illustrator. All my designs were being scaled down 25%! Very confusing until I figured it out.


#15

@dan - another feature request for the hopper. As a user, I want new shapes that I open to be transform-locked (meaning, can’t be rotated or scaled) so that I don’t accidentally change them unless I want to. I’d like to be able to lock/unlock rotation and scaling separately via icons in the UI.


#16

Yes but there is no such thing in OpenSCAD, so I need to know what it actually becomes in the SVG file. I will have to write a post processor to add it. I am guessing it is just the width and height in the SVG header rather than a special element type.


#17

Viewbox, I believe.

If you want to experiment, here’s a simple SVG set up with 20x12 board and a single line.


#18

Thanks. That has a viewbox that exactly equals the size.

x=“0px” y=“0px” width=“1440px” height=“864px” viewBox="0 0 1440 864


#19

Hopperized!


#20

Sorry…a day late and a dollar short. @dwardio and @jbmanning5 are right on…I now just start every new project with a 20x12 artboard.