Drag Knife Cutting Leather

[@storytellerHD]

Thanks for sharing Brian. What strategy are you using for hold down? It almost looks like a double-sided tape of some sort.

[@briangray5067]

Thanks! I have a vacuum hold down on the table, but this is not strong enough to hold leather. So the spoilboard is held with the vacuum. The leather is helped by the vacuum, but mostly held down with double-stick tape.

[@GustavoGuevara123]

Hola, excelente, el motor que sostiene a la cuchilla está energizado como para girar hacia la dirección de corte? Si es asi, podrias explicar como es su conexión con la placa por favor? Muchas gracias.

[@BCFFMedic]

Brian dou have any tips on setting up the drag knife in vcare and running it on a shopsabre CNC? I have the drag knife, but no idea how to use it.

[@briangray5067]

Thanks! I use VCarve for the Dragknife post processing. VCarve has a very handy gadget that makes this easy. You just insert the blade offset, material thickness, tolerance angle, and a few other parameters and VCarve does the rest. You will need to be sure that you assign the starting point (by editing the node) of each cut to all be in the same direction (in my case cutting from left to right), or else the blade will enter cuts at the wrong angle. Check your VCarve software (gadget menu) to make sure that you have the Drag Knife gadget. If you don't, I'm pretty sure that it's free.
And of course...make sure that your spindle is off! I can't even imagine if that blade starting spinning at 18,000 rpm!

[@BCFFMedic]

@@briangray5067 I do have the dragknife in gadgets. When I attempted to use it I got an error saying no toolpath selected. I looked for other videos, but haven’t found one yet that walks through from start to finish. I’ll keep looking through the videos and see if I can make it make sense for my brain.

[@briangray5067]

@@BCFFMedic Yeah, you need to select your vectors first. Then run the gadget and input the parameters. In addition to VCarve's site and tutorials, you might want to check out Donek's site, as they have a lot of good resources as well, probably better ones than VCarve.

[@BCFFMedic]

@@briangray5067 thanks for taking the time to reply, I’ll look into that

[@oscarricardomartinezhernan6937]

hello, Brian, how can use the drag knife in Artcam? thanks

[@briangray5067]

Sorry I've never used Artcam. Not sure.

[@user-vz6hp3wn4u]

So spindle is off and knife move alone only on direction where machine is going , did i understood good ?

[@briangray5067]

Yes, spindle is off (if you ever use a drag knife like this be SURE that the power to your spindle is cut. That knife spinning at 18,000rpm would be so incredibly dangerous). And then the cutting axis of the blade is slightly behind the center axis of the spindle. The knife always 'drags' behind the center of the spindle axis as it moves. So the knife follows wherever the spindle goes, along the same path, just slightly behind.

[@levilena8415]

​@@briangray5067
This system is great. At what exact distance does the tip of the knife work well from the center and at how many degrees of angle is the knife positioned?

[@briangray5067]

@@levilena8415 Honestly, I don't know offhand, but you can see all specs on Donek's site. donektools.com/