qr codes for engraving

[muddy0409]

Has anyone engraved qr codes? Which toolpath was used?
I have a DXF of the qr but will not successfully go into a pocket correctly.
Any tips?

[Adrian]

What happens with the pocket? Could be lots of different reasons.

I would expect that the square corners are pretty important. Ideally a VCarve toolpath would be best but Cut2D can't do those.

[Tex_Lawrence]

muddy, you might find this video interesting for lots of reasons; especially for QR code.

[Adrian]

I must admit I was thinking more of something the size of a credit card.

[Tex_Lawrence]

Vectors are your friend!

I was telling my wife that those would be great on street signs and mailboxes!

Link them to the current location and no one would bother to come knocking on your door during the dinner hour wondering where they are!

PS. Their smartphone would give them the exact location in the map app.

PPS. I'm sort of joking ...

[muddy0409]

What happens with the pocket? Could be lots of different reasons.

I would expect that the square corners are pretty important. Ideally a VCarve toolpath would be best but Cut2D can't do those.

Hi Adrian, thanks for your reply.
I have a bit more of a play with this and think I have worked a few things out.
I am converting the QR to a DXF and have used the original EPS as well. Both of these give different results. The original PNG file is "edge detected" and then vectorised into a DXF which looks pretty good when I import it into Cut2d. It's a bit hard to explain what's happening after that without some pictures to help, but here goes!
If I highlight vectors to do the pocket toolpath, becaust there are lots of individual lines in a given vector which enclose non engraved areas, these do get added to the toolpath, I think because the un-engraved areas are totally surrounded by engraved areas they are included. I am trying to ungroup whole areas of vectors so that I can then manually re-group them into more friendly areas. I still have not worked out how to ungroup large sections of vectors yet. EG if you imagine 2 squares joined at 1 corner which are grouped as a single vector, if I could ungroup them into their basic 8 lines, I could then regroup 4 into 1 vector and the other 4 into a second vector so I could individually select each square. to do 2 separate toolpaths. Did I Explain that right?

[muddy0409]

I must admit I was thinking more of something the size of a credit card.

Hi again Adrian.
My finished size would be pretty close to 2 inch square.
I have an application ready to go, but stuck on this final bit!

[Adrian]

I've looked at some of the QR to vector generators that are available on the web and they all seem to work by creating the qr code out of series of squares which sounds like what you have in the EPS file.

If you use the weld vectors tool (first icon of the second row under edit objects) that will get rid of the overlaps.

The attached toolpath preview was created from a QR code for http://vectric.com with a pocket toolpath using a 60 degree V-bit. It scans fine which surprised me a bit.

[Tex_Lawrence]

The "trick" would be to be able to create vectors that followed the center or "on" profile toolpath.

That would allow one to use a bit sized to fit the profile cutout areas.

Just dumping a bunch of vectors is going to take a long time to cut as Adrian and muddy have alluded to.

I would think that a 2 inch square is going to take a really small bit to get it cut for scanning.

Also, a QR scanner depends on good contrast between the cut and un-cut areas no matter what bit is used.

I've used https://qrcode.littleidiot.be/ to create good error free QR codes (albeit, not for wood.)

[Tex_Lawrence]

This is a bit more complicated to cut than I was imagining, and I'm not even cutting any wood.

[Tex_Lawrence]

The only way I get a good on screen scannable QR code is to use the pocket toolpath with a bit smaller (or equal) in diameter than the vector path.

I used a wood block about 4.5 inches square and resized the QR code (from eps file) so the milled areas were slightly more that 1/8" wide. Then I chose a 1/8" end mill to cut with.

Making the preview 7 inches high on screen, I can scan it up to 4 feet away with my iPhone.

Making the preview 2 inches high on screen, I can scan it up to 1 foot away with my iPhone.

Nothing was done on wood.

EDIT: I did forget that I can ZOOM my camera which is what limits the distance of a scan. If I zoom the QR image into the whole scanning field of my camera then the 7 inch on screen code can be scanned easily at 30 feet. I suspect this depends on the camera, though.

[Adrian]

Did you see my post above?

[Tex_Lawrence]

Adrian, saw your post, but the 60 V-bit didn't work as well or as quickly for me on the 4.5" sq. wood using Vcarve. Do you have a secret?

I was looking for a "universal" method when muddy posted.

[Adrian]

My example was 3" square with the 60 degree bit. Any smaller than that needs a 45 or 30 degree bit. The OP says he is engraving them so that should fit in with that tooling.

I've attached a 2" square one done with a 30 degree bit that scans fine.

[Tex_Lawrence]

Adrian, don't know what I did before to make it not work, because a 60 Vbit works fine now on muddy's 2 inch part and on my 4.5 inch part.

One difference with your graphic is that mine has square holes and corners; yours has round holes. Must not have been cut with a Vbit.

Scans well at 2 inch size from about 6 feet away while the camera is zoomed in full.