Problem of scale on cut parts


#1

Using Inkscape, I’ve created some rounded rectangles that must fit into sockets made on my CNC. I made the sockets, then tried two rounded rectangles of the same size, didn’t quite fit, so I tweaked the size in Inkscape, cutting the pair a couple of times until they fit perfectly. Then I replicated those same two rectangles until I had an array of 8 across and 4 down and proceeded to cut them on non-proof grade veneer and specified the thickness of that veneer. ALL 32 of the new rounded rectangles came out the same size, but proportionally and slightly larger than they were specified to be. The size specified in Inkscape is 0.8" wide x 0.812" high. When I cut the test samples, they fit perfectly. When I cut the 8x4 array, they came out 0.829" wide and 0.847" high (+/- 0.001"). I can send the files and samples of the pieces.


#2

If you can, post the files in the thread and someone may be able to help.


#3

Here are the 2 files:

!

Test%208125|210x297


#4

Test%208125


#5

2nd file didn’t upload correctly in first reply, but did in the second one above.

Dave


#6

Is it possible that you accidentally dragged on one of the squares at the edges of the selection rectangle in the Glowforge interface when you were placing the lines? Because that will resize everything proportionally just a little bit, and it might be what happened here.

Very easy to do. For a difference that small, size wise, it’s the most likely culprit if the size is set correctly in the Inkscape* file.

*(It’s also possible to be off by the thickness of the lines used in Inkscape - the actual cutline runs through the center of the visible line, so if your line is four points thick, the actual cut will happen two points smaller than you might expect. I think there is a setting somewhere that you need to set to avoid having the line thickness included in actual measurements as well, something to uncheck or check concerning graphics, but I’m not sure where it’s located.)


#7

Jules, your experience is invaluable! That is exactly what I did - wish they’d fix that little issue with the software - and suspect they will eventually.

When I first placed it, I went to move it onto the target material and only one of the squares moved. I tried to place it back (didn’t have to be exact) and moved the whole shebang. This was the result.

I started fresh and cut the shapes - fit fine. Then redid it and moved just one first, then all of them and sure enough. THAT’S ANNOYING - and I truly hope they fix that soon! How does one report an issue to the company??? (I’m a newbie).

Thanks again. I can now proceed to doing my work.

BTW, in your experience is there a published guideline for power vs. speed in engraving and cutting on wood? I’m not using proof grade because I must color the material before placing the protective film and cutting.

Dave


#8

Opening this thread in Problems and Support notified Support of the issue, so you’re squared away there. :slightly_smiling_face:

I can suggest doing a search in the Beyond the Manual category for starter settings on specialty materials, but for things like woods, its pretty easy to start with a similar thickness of Proofgrade material and the settings are good for a first test. And the Acrylics are pretty much the same based on thickness as well.


#9

It sounds like you’ve got things figured out, but I’ll mention this just in case. In Inkscape, when you draw a rectangle, you can specify the size precisely. However, if you use the “select” tool and pick the object later you will be looking at the rectangle size plus the stroke width. Any changes to size here will include that stroke width. I believe you can change that behavior in settings and someone told how to do that somewhere here on the forums. You can also select the shape and then click the rectangle tool and make your adjustments there, but if precision sizes is your thing and you are on Inkscape, I’d try and change the behavior. I’ll see if I can find it in a bit.


#10

Also, just fwiw, I tend to have my best luck when moving stuff with the arrow keys, and when selecting by doing an area select (drag a rectangle) around the thing I want.


#11

I am very sad and dismayed to report that there is another snake in the woodpile. I just very carefully crafted a new file and uploaded it. I did not move one item, but rather grabbed all of them and then moved them into place. The pieces came out 4-5% larger than requested. The cutline is .005" - so middle of the stroke is probably not the issue.

I don’t know whether the problem is Inkscape or Glowforge, but right now I’m not impressed with either. In the first case, it’s free software and proves the ole adage, “You get what you pay for.” In the latter case, I’m quite surprised that the software is this fickle and hope that it matures well and soon.

:o(
Grumpy Dave

FINE! Just attempted to upload the SVG file for this issue and it hangs at 0% uploaded - four times. AAAAAARRRRRGGGGHHHHH!!!


#12

Five percent larger means it might have gotten resized again during moving, and it would have resized all of them at the same time…one thing I’ve noticed is that the cursor is different for moving than for resizing - the moving one is a four way arrow. It also helps to select one of the items in the center of a group to move everything instead of at the edges…less chance of accidental resizing.

Not to worry…it happens less and less with practice. (But it still nails everyone once in a while. :smile:)

CTRL+Z to undo is your best friend.


#13

You can also move objects using the arrows and shift-arrows.


#14

Ctrl-Z, eh? Who knew?

Thanks, everyone.

Have dumped Inkscape for now - back to AI and/or CorelDraw. Know them best and feel MUCH more comfortable that they aren’t contributing to the mess.

Wish Glowforge would teach itself to handle text better - sigh!

Dave


#15

If you’ve got AI, use that. Use whichever one you are most comfortable with, you don’t gain anything (except headaches) from having half a dozen different drawing programs that you are trying to remember how to use at the same time. :smile:

They all do the same thing.


#16

Except that the GF standard is Inkscape and testing seems to be oriented around projects designed in that. Everything else is going to be subject to the vagaries of that product’s SVG conversion routine and how well it matches to Inkscape’s. They do seem to do work in AI as well but that’s no guarantee that all things in AI will work properly when run through the SVG filter. So any other package is not a guarantee of success (remember the sizing issue with the need for the unchecking of the default responsive box in AI? :slight_smile: ).

Edit: Oh, and Corel does everything better :sunglasses::stuck_out_tongue_closed_eyes: :popcorn:


#17

That’s because “responsive” removes the width and height attributes. Glowforge can’t fix that without being mind readers (which seems to be expected of them).

Says the guy struck by the fill-rule debacle :wink:


#18

Yep. But that was the GFUI and it also affected anyone using Photoshop, Fusion and AD. AI could also have been affected except apparently most people leave the defaults because AI also supports the valid SVG fill rules that the GFUI doesn’t. :smile:

It also affected any Inkscape open/save of files from those programs as well. As I noted, the only really safe one is Inkscape native files (created, not just opened, in Inkscape) because that appears to be the test platform.


#19

You Corel people are cray-cray! :wink:

What I meant was, the drawing programs all perform the same overall functions - it’s just a question of using the one that you are most comfortable with.

There’s no sin in using Corel over Illustrator, or Inkscape over Affinity Designer - each program has pluses and minuses from a standpoint of ease of use. It’s just taking the time to get comfortable with how each drawing program works, and unfortunately, sometimes it means accepting that certain functions might not have full support yet from the GFUI. They’ll get there eventually, but they’re focusing on Inkscape right now because it is a free alternative, and as such, probably the vast majority of users choose it. Illustrator is probably the next largest in terms of number of users and professional designers, so it gets developed for too. It probably didn’t hurt Illustrator’s case that both of those use similar SVG formatting either.

CorelDraw does do some things much more easily than Illustrator or Inkscape though, so maybe it’s worth the SVG hassle you currently have to put up with. It won’t be forever.


#20

Yeah - it’s an arms race for features. What’s in one will end up (eventually) in all of them.

I teach using Inkscape because it’s free. Most people don’t want to spend hundreds of dollars for a software package when a free alternative does almost everything as well. It makes teaching easy because I know they all have the same tool available so I don’t need to worry about explaining 3 ways of doing something. Corel is my religion because I grew up with it. AI is my sons’ because they started out as graphic designers on purpose so I have to keep some familiarity with it so we can collaborate on files sometimes (but that’s a bad thing to try - if you don’t use a package a lot it’s easy to forget or to get things mixed up moving from one to the other).