QR code in solidworks

[mare69]

Hi,

I was looking for easy way of embossing the QR code into solid. There's no easy way of doing it. The QR code could be good and compact way of marking the parts or to track the moulding tools inventory. I think it's worth adding few extra minutes of machining...

Here's a step-by step tutorial I prepared recently if anyone interested:
http://e.pavlin.si/2013/12/15/qr-code-in-solidworks/

Recipe in few words:
- prepare vectorised QR code composed of individual squares
- reduce the square size (each square individually) to avoid "invalid geometry condition" during extruded cut
- save to DXF and use for extruded cut
- repeat extruded cut with same drawing and thin feature to remove the walls around square pools

Any comment appreciated

M.

[solutions]

A classic case of what you draw you cannot make.

Short of etching it chemically, how do you propose to machine this?

[mare69]

You are right. It can't be done using conventional milling. It would require EDM (die sink or wire). I attended compamed fair few weeks ago where I sam some fascinating micromachinig capabilities. There were 50 microns milling bits shown. I have 0,2mm (8 mil) milling tool for my home made CNC mill, which is more or less limit for DIY. 

[Parmin]

Here are an example that managed to make QR codes in metal billets
CNC milled
http://hackaday.com/2013/12/16/aluminum-bitcoin-keychain/

Or you can try chemical etching
http://hackaday.com/2013/10/27/electrochemical-etching-with-a-microcontroller/

[solutions]

^ The stencil etch they propose doing is nifty, but won't work for QR codes because they have islands of no-etch areas. You need resist put down, exposed, washed off blah blah blah

I'm also not too keen on a 3 inch (75mm) square QRcode that's machined out

Interesting, nonetheless, Parmin.

Yes, an EDM sink can do it - but you still have to create the sinker and have an EDM machine => put your hand up if you have one.

I also am interested (show your math) at what speed you think you need to spin an 8 mil cutter (let alone a 2mil/50 micron) and what you think your spindle runout is.

Sorry for being a wet blanket, it's just that I've seen several very interesting SolidWorks designs, designs that were impossible to make without starting with a bar of gold.

[Parmin]

^ The stencil etch they propose doing is nifty, but won't work for QR codes because they have islands of no-etch areas. You need resist put down, exposed, washed off blah blah blah

Sorry, but huh?

I have used the same etching equipment and no problem with no etch areas, no resist need to be put down or exposed nor wash out blah blah..
The stencil is simply thermofax system that you can easily make with some help from your local friendly tattoo artist.
In fact I have done so to make overlay stencils for my PCB in a hurry (lucky a tattoo studio is just across the road from me.

[solutions]

How do you make a stencil for this area?



I submit you cannot, but I'm willing to learn new tricks

[Parmin]

The stencil is made of similar stuff as the screen printing equipment, so there will be no bridges for enclosed islands.
There will be no problem to make stencils as in your image.
No problem at all.

I have made similar silk screen of QR codes on the PCB overlay using the same technique, so there would be no reason why it wont work in etching.

[solutions]

I don't know if you are seeing it.Parmin.

It is impossible (I think - maybe you know something, but you haven't said how) to create a stencil that will do concentric rings or rectangles without having support tabs in place. That means you need resist, which is a stencil held in place by the substrate and which can do concentric structures without tabs.

In other words, do a quick sketch of the stencil for the area I circled exposing the etch to the black portions. I don't see how you can do it without tabs, which is then no longer faithful to the pattern.

[CocaCola]

You can easily create a negative on fine 'silk screen' like stencil material and then transfer a traditional resist to the metal and etch from their...

Or coat the metal with a photo-reactive resist and using a transparency expose, clean, etch it like they do for presensitized pc boards...

Or simply do what most companies do now, laser etch it...

[solutions]

Laser's a good idea. But you don't need to do that part of the geometry in SW.

I'm with you on the resist. Any number of ways to put that one down.

Just not up to speed on the stencil/sponge method Parmin seems to know how to do

[CocaCola]

Laser's a good idea. But you don't need to do that part of the geometry in SW.

True but the 'extrude' button is hardly that hard to click for visual effect   I have personally used SW to draw laser and water jet cut profiles even though it way overkill, and for some reason I can't resist extruding it and giving the part a 3d roll around...