This may seem like a no-brainer, but it’s actually pretty easy to modify your CNC machine to hold a vinyl cutter blade in order to do stencils or even cut out vinyl logos!
[Jouni] designed a holder for a standard Roland vinyl/sticker cutter blade (replacement with 5 blades is about $10 on eBay). It’s made to fit his specific CNC which uses a 65mm spindle, with a 49mm mounting ring — but the file could be easily modified to suit others.
Simply clamp your plastic or vinyl onto a flat piece of wood, and get stenciling! [Jouni’s] included his .STL file on his site in case anyone wants to try it out. While he’s designed it for 3D printing, you could probably CNC mill it as well — which would kinda make more sense…
And now that you have a vinyl cutter, why not cut your own SMD stencils for making your own PCBs!
I see a one problem cutting small things, because the blade is not centered. Some time ago i try to cut stencils with my 3d printer and a similar vinyl cutter, and I found this problem:
https://twitter.com/javrodara/status/574530658334285824
Gcode has the ability to apply offsets. How do you think printing with multiple extruders works?
You can put the offset right in the toolholder config for the holder that you have the knife in so it picks it up on toolchange, that is great for auxillary spindles with a X offset from the centreline of the main spindle etc.
But in this case the fly in the ointment is the vector of the offset changes with direction, so the cam software needs to be aware its a special case and to apply some directional logic to do sharp corners and turns correctly.
Happily most cam software has dragknife toolpaths as a option which will do this for you.
That is a different kind of offset. A vinyl cutter compensates by dragging the center of the holder past the corner point, then swinging it back in as it cuts in the new direction.
The dotted line is the path that the centerline of the blade holder takes:
http://www.cambam.co.uk/forum/index.php?action=dlattach;topic=1244.0;attach=3231;image
I have an old Graphtec vinyl cutter, the cutter itself performs this offset compensation. Which is very nice, because then your program just tells it what to cut. It cuts a square with a triangle inside it as a way to test the compensation. Too little, corners are round. Too much, the corners get peaks on them.
https://cmi.epfl.ch/packaging/img/Plotter_Cutter/test_cut.jpg
Unfortunately not a tangential knife. Try zig-zag with this, it just won´t be clean at all. There is room for improvement !
I have used these blades on a Silhouette cameo and can get down to sub millimetre accuracy. They are a drag knife so admittedly not as nice as a tangential but they are still great blades.
I did this with a glass cutter one time – worked great for making a large number of perfect glass circle’s
This is very interesting. I am wondering if this could be improved by mounting the blade on a motor to change its cutting direction? I have seen this on standard vinyl cutters, didn’t see too many detail in the article. Perhaps he does that already.. I’m wondering what sort of modifications to the controller and/or gcode that would entail. Very cool project
Most standard vinyl cutters actually use a “drag knife” – the same type used in the article. If you can’t get the desired precision with a tangential blade & drag knife you’re probably using the wrong cutting tool or doing something wrong.
Is it possible to just chuck that attachment? Maybe put it right in a collet?
My thoughts too, I’ll know a answer to if it can be jammed into a qc30 holder when ebay delivers after seeing this article :-)
You can make another adapter to be chuck it in. But that engraver/mill is apparently lacking the required Z travel. The guy even took out the ER nut on the spindle for more clearance, it seems.
If you have a mill with an R8 or larger spindle it should be possible to get a collet the right size (likely metric) for the knife holder.
One trick to sharp corners with a drag knife is to do a loop, cut past the corner, loop around so the knife approaches the other side of the corner straight on from the waste side. That works for outside corners. Don’t know how it could be done for inside ones. Probably should just make those to the minimum turn radius for the drag knife.
See my replies above about offset compensation for vinyl cutters.
i would rather just poke a small hole in the center or somewhere in the design that will be unused space, and thread a hot wire (ie: kanthal, nichrome, whatever resistance wire) between the top and a bottom portion that would travel the same places. but i guess then you’d have 2 CNC’s, one above, one below, one feeding +Voltage, one being ground. I’m not sure if you can cut vinyl that way though, and still have perfectly flat vinyl.
Cutting vinyl with heat is not recommended. It does have the tendency to let out toxic fumes when melted. This pops up regularly in the laser cutting forums.
wow i’ve never known we can turn our CNC into a Vinyl Cutter. but to make our life easier, we can choose a completely cheap & powerful vinyl cutting machine is better. I bought Cricut Explore AIR 2 machine from this page: http://bit.do/cutting-machines . it is really easy to use and compact.