Thread: Drag Knife anyone?
No idea about the triangle bits left over :-(
Here's a diy build: Build Your Tools • View topic - DIY Stencil Cutting Drag Knife Solution - Update 5!
Rockcliff do a holder for $70 here: Rockcliff CNC Machine Inc.
Here's an article from the Rockcliff forum aparently Mach 3 has a tangential knife routine for motor driven blades that does all the lifting and dropping and turning: tangential knife cutting Styrene - CNC Machine Builders ROCKCLIFF Forum, Register it's free
Hope these help.
Drag knife is what a vinyl cutting plotter uses, but material thickness is fractions of mm up to a couple mm mebbe thick, blade just turns around on bearings in its holder, Z is solenoid up / down.
Though plotter makers seem to have no problem with high res USB to stepper interfaces.....
For things with some thickness like foamcore and correx, its CNC with an oscillating knife , drag knife wont go to multiple mm in stiffer materials, which is partly where I started looking at CNC
COMAGRAV oscillating tangential knife
For the sort of cash for a drag knife gadget, if you want to cut vinyl not far off a whole cheap plotter for similar cash.
I was pleased when I opened the cover of the pen holder to find it had a blade thingie. The bloke told me it was a "Roland knife". The blade is
mounted in a bearing, but it doesn't look like the point of the blade is on the axis of the body! Dragging it around on my thumb[doesn't seem
very sharp] the blade seems to self centre really well, so it turns and is always pointing in the right direction.
I haven't yet tried the thing, only had it about a year;-)
I actually want it in the next few weeks to cut all the masks for some lettering, I can't afford vinyl sticker sets.
Had a small vinyl cutter at school...had some fun making 'test stickers' when they got it
Should have said Z axis on a cutter actually has downforce adjustment , rather than just up down, allows for cutting vinyl without going right through its backing sheet,
Glad to see our tool is getting some discussion here. I thought I would take a moment to address some of the topics being discussed.
There are a number of vinyl cutting tools available, but they are not typically effective at cutting materials thicker than vinyl. Our tool is capable of cutting to a depth of 6.4mm without tearing your materials. It is being used successfully to cut veneer, leather, cardboard, gaskets, and many plastics ranging in thickness from 1.2mm to 6.4mm. The corner operations can be tricky to program, but we are working on a couple of different programs to facilitate programming the actions with a mouse click. Most objects being cut do not ever require sharp corners, so this is not typically a problem. There is a small amount of material left in corners. This is not typically a problem when separating the parts. swapping parts in veneers and other inlay applications is no problem as the tool has such a small kirf. Unlike laser cut veneers or routered inlays, it is no longer necessary to throw away half the material being cut. If you cut a dark and a light part and swap pieces, you retain two usable parts rather than only one.
There are other competing products on the market capable of doing similar things. Tangential knife products using a motor to orient the blade for cutting in the correct direction are an excellent solution, but tend to be cost prohibitive for the average user. These devices when purchased from other manufacturers typically start at $5000 US and go up very quickly. They require specialized programming and driver software capable of controlling a 4th axis in tandem with the usual 3. This tool is completely passive and accessible to anyone with a cnc router. It simply chucks into your existing 1/2in collet (we have a 1/4in tool in development). Our tool uses a specific,yet standardized blade that is accessible to anyone making the long term operation far less expensive than tools requiring $25 blades. Sorry about the US currency.
We are patent pending on this technology. The duplication of it is actually much more tricky than one might think. There are very important things that come into play in the proper function of this tool. Simply going out and trying to make one might yield some usable results, but to get the results possible with this tool would require a lot of attempts. This tool has undergone a great deal of development. Versions of this tool have over 11 years of use in production in our snowboard production as well as other snowboard manufacturing facilities.
Thanks donek for the reply. When I finally get my machine built you may have yourself a UK customer!!
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