First Time CNC Project, Beginner Question

[Thomas McCurnin]

So I am making a run of Shaker type dovetail footstools 12"h x 12"w x 18"l with a design on the top, personalized for the person(s) who will receive these, using a router to make a simple groove of the design. By way of example, one of the designs will that of our local mountain, San Gorgorio Mountain. The design will be about 5x7 inches. I may add an outline of a bear underneath it and a pair of Ponderosa pines to the side, if I am on the right track.

I have zero artistic ability from a drawing standpoint, so what I did was grab a good picture of the mountain and using Adobe type photoshop software, strip everything off the photo except the outline of the mountain and a few accent lines for valleys. The resulting outline is about 3 pixels wide, about 8x10 canvas, solid black with everything else erased, not whited out. I used the erase tool. I intend to give this modified jpeg or Adobe type software file to a CNC guy to convert to a file which can be recognized by a CNC. I think I've read the file is a "G" type file. Once the top part of the stool is done and dovetailed and ready for glue up, I'll have it CNC'ed with the design. My assumption is that being a router type groove, the design has to be relatively simple and in solid black.

I attach the photo of the mountain, and the resulting outline. Am I on the right track here? Thanks for all who respond.



San Gorgonio Mountain.jpgSan Gorgonio Mountain Outline2.jpg

[Carl Beckett]

It seems viable approach.

The VCarve software allows you to import a bitmap file and create 'vectors' from it based on the outline. You can play with contrast to get the lines you want - but you have it already..

This can be used to carve the shapes - or you could use it to create inlays.

I think you have enough to give directly to your CNC programmer. But I think they may want to mill the surface before any glue up.

[Jim Becker]

You ideally want the image converted to vector(s) but some CAD/CAM software, such as Vectric's products can directly import a bitmap and convert it to vectors. That will likely need further editing, but it's a good opportunity to learn node editing which, IMHO, is a critical skill for doing this kind of work. I actually have to do that with virtually all the vector art a friend I help out provides. He gets them from Shutterstock and nearly all of them were created in Illustrator and have a whole bunch of wonkiness (technical term... ) that just does't cooperate with toolpaths without modification.

[Thomas McCurnin]

What does "convert to vector" mean? My Adobe Photoshop clone can convert to jpg, bitmap, tiff, giff, pdf, psd, wmf, eps, exr, hdr, and tga.

[David Buchhauser]

What does "convert to vector" mean? My Adobe Photoshop clone can convert to jpg, bitmap, tiff, giff, pdf, psd, wmf, eps, exr, hdr, and tga.

Thomas - the most common vector file formats used for 2D cnc work (at least for me) are dxf and svg. Vectric Aspire/VCarve Pro will import the following vector file formats.

David

vectorization 1.jpgvectorization 2.jpg

Here is an explanation of "vectorization" that may be of some help to you.

https://research.ppld.org/laser/Vectorization
vectorization.jpg

[Thomas McCurnin]

Ah, so if my photoshop software converts to svg, I give that file to a guy that has a CNC router, and we're good?

[David Buchhauser]

Ah, so if my photoshop software converts to svg, I give that file to a guy that has a CNC router, and we're good?

Thomas -this all depends on the source of the file you are converting to svg. If this was an auto trace of a jpeg or bitmap image/photo, then most likely some clean-up will be required. Depending on the program you are editing this vector file with (in this case svg) you may be doing "node editing" as Jim referred to, or perhaps some trimming, redrawing, etc. Here is an example of a request I recently had to convert a photo to dxf.


charlie coyote.jpg

I started off opening this jpeg file with Paint.net to convert to black and white, adjust brightness/contrast, and invert image - all things I know from past experience will greatly facilitate the "auto trace" conversion from jpeg to vector format. I then imported this result to Inkscape and performed an auto trace (in Inkscape this is called "Path, Trace Bitmap".

This is the result of the auto trace.

quick auto trace.jpg

The coyote portion is usable with a little bit of editing, but the letters are distorted since the shirt was not laying flat when the photo was taken. I drew the letters by hand (manually drawing using the Inkscape "Bezier Draw tool) and edited to my liking. All of this editing and drawing is done in vector format after the original conversion from jpeg to vector format. I would expect that your Adobe program has some similar tools for drawing/editing. Here is what the file looks like as nodes.

vectorization 3.jpg

Here is what it look like in regular mode (nodes not visible) and with fill color added.

vectorization 4.jpg

Once the editing is complete, then this file may be saved as dxf, svg, or several other vector formats for import to the program to be used for creating the cut paths and g-code.

If I save this file in svg format and import to Aspire, this is what it looks like.

vectorization 5.jpg

If I do a quick engraving tool path, then this is the cut preview.

vectorization 6.jpg

So you can see that there is often much editing to be done after the initial conversion from bitmap/jpeg to vector format. Of course there are other simple examples where the auto trace produces a usable file "as-is". Also if you are drawing your project using your Adobe program and then saving as svg you should have a pretty clean file to begin with.

David

[Jim Becker]

What does "convert to vector" mean? My Adobe Photoshop clone can convert to jpg, bitmap, tiff, giff, pdf, psd, wmf, eps, exr, hdr, and tga.

Vectors do not have pixels like most of those other formats do. They are literally "lines" with what are called "nodes". The space between the nodes can be straight lines, arcs or bezier curves. EPS is a vector format, however. You can try to export the graphic that way, but I strongly suspect you're going to have to do some node editing to get the image ready to actually toolpath and cut.

[David Buchhauser]

Ah, so if my photoshop software converts to svg, I give that file to a guy that has a CNC router, and we're good?

Thomas - post one of the files you are considering converting and we can walk you thru it.

David

[David Buchhauser]

https://pavilion.dinfos.edu/Article/Article/2223089/vector-vs-raster-images-choosing-the-right-format/
vectorization 6.jpg

https://documentation.corelvector.co...tor-vs-bitmap/
vectorization 7.jpg

[John TenEyck]

My advice is to just give the CNC guy the file you now have, whether it's jpeg, or whatever. If the guy has just basic experience he will know how to convert it into the format needed for his software to generate the toolpaths. Have him send you a copy of how it's going to look for your approval.

This is the process I use with a guy who just wants me to cut designs for him. He doesn't care about the mechanics, nor should you unless you want to start doing CNC stuff yourself.

John

[Carl Beckett]

My advice is to just give the CNC guy the file you now have, whether it's jpeg, or whatever. If the guy has just basic experience he will know how to convert it into the format needed for his software to generate the toolpaths. Have him send you a copy of how it's going to look for your approval.

This is the process I use with a guy who just wants me to cut designs for him. He doesn't care about the mechanics, nor should you unless you want to start doing CNC stuff yourself.

John

+1 on this. Seems you have enough and straightforward for your CNC contact to take it from there...

[Jim Becker]

Ach...I completely missed that you were not doing the CNC work, Thomas. Your "CNC guy" should be able to deal with the image work...just give them the file and your specifications for size, etc.