Drag Knife - turn your CNC router into a vinyl and box cutter

In this jolly old episode we make a drag knife. If you did not know its a type of cutter that fits in a cnc router. Once installed it can cut signs and cardboard etc etc.
I needed it to make cardboard boxes and parts for a few products. Being tighter than a Lamborghini head gasket I could not bear to part with lots of beer tokens to buy one so I made one instead.
Bit of a learning curve but damned chuffed with the result. Slicing cardboard with a guillotine took around two hours this does the same thing more accurately in under 30 mins. So worth the time taken to design and make it.
Cost wise it was pretty much free, prats came from scrap bin ( bucket of broken dreams)!
Hope you like it anyone wants the design give us a shout.
Cheers

[@qta4425]

"This is the tool that I plan to use ... uh, because it happens to be in the tool holder" Love it! This is how it is really done.

[@CazualHaze]

Frugal or lazy take your pick!

[@qta4425]

@@CazualHaze Not lazy, just completely honest. That's what makes these videos so useful :) Enjoyed it.

[@doulos5322]

awesome project works well and I'm gonna steal that mirror trick!

[@CazualHaze]

Thanks for the comment a mirror is damned handy if only to check your lippy! LOL

[@xandersnyder7214]

Painters tape and CA glue has been a game changer for me in terms of work holding!

[@CazualHaze]

Me too great on my cnc mill. Even using flood coolant has not dislodged the work! Cheers

[@VigilantnotMilitant]

This video helped me connect some dots. Thank you

[@CazualHaze]

Glad it helped

[@dimmaz88]

Great video, and a great final product. I'm looking for inspo for making one of my own, I hope I can figure it without having a lathe or mill :D. My CNC router will have to do.

[@CazualHaze]

You can do it! I have even seen 3d printed ones, who'd have thought!

[@TheLimalha]

GOOD JOB !

[@TheElderlyBiker]

That works very well - great job.

[@CazualHaze]

Thank you! Cheers!

[@julias-shed]

Think this would make a great upgrade for my engraver 😀

[@CazualHaze]

Thanks for the comment. I used mine to make boxes and inserts for flower presses. I will be revisiting this in the future and making plans etc available. Cheers

[@julias-shed]

@@CazualHaze I was considering buying a cheap cricut but this would work well for vinyl paint masks for models I think. Or maybe with a scalpel blade instead 😀

[@Tchefter]

Congrats! Cool Job and it works fine!

[@CazualHaze]

Thanks!

great job... thanks for video

[@CazualHaze]

Thanks for watching!

[@homemadetools]

Good job. We posted this video on our homemade tools forum this week :)

[@CazualHaze]

Awesome! Thank you!

[@juanmarmo70]

Nice job! What software are you using for programing the DXF?

[@CazualHaze]

Hi Juan, its all done in fusion 360 cheers

[@BEdmonson85]

One thing about painter's tape, as you noticed, is that actually, the longer it's bonded to a surface, the harder it holds. If you've ever started a paint project and stuck it to a recently painted surface and then take a break from the project for a week or so and then come back and remove the tape, you have to take care not to rip off the paint... found that out the hard way lol.

[@CazualHaze]

You are spot on yesterday shooting another video it broke free and wrecked the part. The tape was only applied for twenty mins before I started the cut. Now I have the pleasure of starting again!!

[@BEdmonson85]

@@CazualHaze Oh no! Hope it turns out better on the next go. Personally, if it were me, I'd just glue the part directly to the pallet. As long as it can take the heat, you can use a heat gun or torch to soften the glue and pop it right off. You'll just need to clean it up with a bit of acetone.

[@BEdmonson85]

With that said, even if you do glue it on directly, heat can make it come loose too, so make sure you have good cooling while machining. :)

[@CazualHaze]

Having another go right now so far so good reduced the Feed and depth of cut (doubled the cycle time) using flood

[@christianrabe2508]

Sehr schöne Arbeit! Klasse!

[@CazualHaze]

Cheers

[@bstanga]

I have a 4x8 cnc router and I'm ready to try cutting AL

[@CazualHaze]

Good luck the noise is horrendous!

[@bstanga]

@@CazualHaze I just did my first Aluminum sign yesterday, only broke 2 bits, it there a way to send a pic?

[@CazualHaze]

My email is in the about section of my channel. Not sure if they allow it but give it a go.

[@akka4751]

hello, great great video! did you publish the plan??? greetings from serbia!

[@CazualHaze]

Hello Serbia no plans yet! I will sort plans in the future. Cheers

[@joecnc3341]

LIked-Subscribed-Notified. Can you share the Fusion files?

[@CazualHaze]

Hi Joe, I am building a website where the files will be available. I will make a short video when its done. Cheers

[@_madmadmat]

Beautiful work! How do you make the spindle turn following the 2D contour? Do you use a plugin?

[@CazualHaze]

Hi @_madmadmat The spindle is free to rotate. The cutting point is behind the centreline of the spindle. So it casters in the direction of travel. Just like a supermarket trolley wheel. Cheers

[@_madmadmat]

@@CazualHaze Thank you!

[@emadsabar]

Awesome video, I would appreciate it if you could share the design.

[@CazualHaze]

Hi @emadsaber I will be putting up the design onto a website but as yet have not had the time to get it done. I will make an announcement when its all finished. Cheers

[@nigelthomas3365]

Great video, the drag knife works really well, could you supply files to make one? I can’t make one myself but will get one made by a cnc service if you supply files. Thx again for taking the time to make the video

[@CazualHaze]

Hi Nigel, Thanks for the enquiry. I will release files on my website which is still under construction. I will post a video when its done thanks. Cheers

[@northotagogolf]

May I ask Dave what are the bearings you used? Cheers.

[@CazualHaze]

I’m not sure the knife is in storage with most of my tools but I think it was D20 d12 and whatever the width comes out at. There are two of them to give the shaft some stability. Cheers

[@leoamaru9796]

Thanks for sharing your work ! If I understood correctly the head of your CNC doesn't orientate the cutter ? He turns freely and only the X and Y movement orientates it, right ? Can it cut more complicated shapes than squares such as curves and so ? Thanks a lot for your video ! 😊

[@CazualHaze]

Thanks Leo, yes the cutter is free to rotate it follows the direction of cut in the same way a supermarket trolley wheel follows or casters in the direction of travel. It can cut more complex shapes and curves however it is limited in what sizes and how tight the corners are. If you need really intricate stuff try a company called cricut. Cheers

[@himanilsharma2147]

Hi, I want to know one thing that, How does the drag knife rotate..??? Does it rotates itself in the direction with the drag force or the spindle is rotating it..??

[@CazualHaze]

@himanilsharma2147 Hi knife casters it's cutting point is behind the rotation centreline. Thats a fancy way to say it casters like a supermarket trolley wheel. The spindle is not running at all. The posh ones have a motor and rotate under computer control. I think this is called a tangential knife. Cheers

[@TheRainHarvester]

If others are lazy and don't create a guard, use thick tape over the exposed blade to avoid cuts. Make it stick out as an antenna. Cuts suck! But make a blade guard instead!! What free cam tools work for drag knifes? I found freecad has a path fixup for drag knifes. Anyone use it?

[@CazualHaze]

Spot on with guards, these cnc machines dont take prisoners! get in the way at your peril. I use the plugin for fusion 360 but it's not free $9.99.

[@paulvanlith3429]

great machining, love to make it myself, if you still have the design, i'd like to have a go on that as well!!!

[@CazualHaze]

Hi Paul, I am working on a website or patreon where the files can be downloaded from. If all goes well it will be before Christmas. Cheers

[@th3oryO]

@@CazualHaze Hey there, did you ever happen to get something set up?

[@francioscollins4128]

Great design. How do we get a hold of the cad. Cheers

[@CazualHaze]

Hi Francios, I will be putting the design up on patreon. Its taking awhile to get it all sorted out though. I will do a channel announcement when its all ready. Cheers

[@gunracksonline]

very nice I was researching cutting leather with a drag knife, do you think it would work to cut leather? Is there anyway i could get a drawing so i may try to make one of your drag knifes?

[@CazualHaze]

Hi Jaustin, Thanks for the comment, I think it is likely to work with leather. I am setting up a website so people can download files etc. Bear with me it is going to take a little while. If you are in a hurry try this one www.cnccookbook.com/build-drag-knife-cnc-router-mill/ Best

[@emmanueldare990]

Awesome video. For some time now I had been wondering if its to build one to cut out boxes from cardboard just as you did, so this video has really made my day.. By the way which software can one use to generate gcode from dxf (allowing the cnc to make both cut and crease lines)

[@CazualHaze]

Glad I could help! I use fusion 360 for Autodesk. The version I use is paid for but they do a free hobbyist licence. The gcode need to be processed using a plugin from their App store apps.autodesk.com/FUSION/en/Detail/Index?id=3603732473616813300&appLang=en&os=Win64 I will eventually sort out a website where my design files can be downloaded from. Cheers

[@emmanueldare990]

@@CazualHaze oh OK, I see. Thank you once again

[@davered27]

Great video thanks... Could you please tell me what angle did you set the blade and how far is the tip behind center of the axle?

[@CazualHaze]

Hi davered27, The blade angle is 45 deg the offset is circa 2-4 mm I think it depends on the thickness of the material you want to cut. Good luck making one. Mine has saved hours of work with a guillotine.

[@davered27]

@@CazualHaze Thanks very much, that's my afternoon sorted..!

[@bstanga]

What a great job, subb'ed your channel, would you mind sharing the f360 file or stl ?

[@CazualHaze]

Bear with me I will sort out in a few days

[@xander_fP]

Hello! Can you please tell me how the knife moves? Software, motor or mechanical due to the movement of the axes?

[@CazualHaze]

Hi the knife pivots on the spindle axis and acts like a caster wheel. It follows the direction of the axis travel. the knife point is 2-3m behind the spindle axis. I hope that helps cheers

[@xander_fP]

@@CazualHaze Большое спасибо за ответ)

[@battles151]

Why did you hook up the air?

[@CazualHaze]

Hi Mike, I think you mean the air on the cnc router? Its actually a vacuum hose from a vac cleaner. What happens is it evacuated the air under the cardboard the table is hollow the differential pressure from atmosphere compared to the table forces and holds the card in place. The clamping force is quite considerable depending on how much vacuum you can pull. At the max of zero pressure in the table the force is 15lbs/square inch. I think my table can get to 5lbs /square inch. Once clamped its hard to move the card however if the vacuum collapses it falls to pieces instantly. Cheers

[@JoseSoto-ez6su]

hola soy de venezuela me gustaria tener el diseño es muy bueno

[@CazualHaze]

Hola, estoy armando un sitio web donde se pueden descargar los archivos. Avisaré a todos cuando esté listo.

[@jawdatattar]

What does it take to get the blueprints

[@CazualHaze]

Bear with me I am sorting something out I will make a channel announcement when its ready. Cheers

[@jawdatattar]

@@CazualHaze no worries thanks for replying

[@angelicacuaya3110]

Good morning, excuse me, could you send me the design, I'm very interested, the truth would be very helpful, thanks. Greetings from Puebla, Mexico.

[@CazualHaze]

Hi Angelica, I am sorting out a way to download the files bear with me. I will announce on the channel when I have it sorted. Cheers

[@angelicacuaya3110]

@@CazualHaze I think it's perfect I'll be visiting the channel thanks for solving the doubt greetings

[@CazualHaze]

Welcome aboard

[@bubba6945]

put super glue on the cut finger and you wouldnt need a bandadge

[@CazualHaze]

Good thought! Cheers Bubba

[@ronallaser4398]

do you sell, the protype,,?

[@CazualHaze]

Hi Ronal laser, Sorry I have only got the prototype so cannot sell it. Cheers

[@ronallaser4398]

@@CazualHaze okey. fine,,,

[@sareythun69]

can i have a drawing?

[@CazualHaze]

Hi @sareythun69 I will sort out drawings and website. I will make a channel announcement when I have sorted it all out.