tried cardboard this time

the drag knife design is interesting as it has to be balanced in such a way that when the router/spindle moves the blade follows or it could snap off the end.

Because the blade is out aout 1/4 one should be able to cut 1/4 material.

There are probably some tricks in aspire to help this cutter do a better job

I would like to find some vinyl to cut letters from as cutiing vinyl with a laser produces bad gases,also cutting veneer will be interesting




using a drag knife to cut cardboard - YouTube

ask sean martin if you spec questions smartin@donek.com

 

My wife has a Cricut and a Silhouette Cameo and die cuts stuff out of vinyl sheets very often. I see you're in Canada, and know nothing about what stores you do or do not have convenient, but down here she purchases the (adhesive-backed) vinyl in sheets and rolls from Michael's and Hobby Lobby. She also finds it at several vendors that are online. Good luck, some of the things she makes are extremely intricate. Otis Guillebeau

 

Yup, we have Michael's up here as well. Wifey's into the whole paper hobby thing, big time.
Lots of other papercraft shops around, but retail overhead is killing small retail outlets.
Best Buy and Future Shop closed a bunch of their big box outlets last week...employees got no prior notice (they did get some kind of severance package).

 

If your are wanting to cut sign vinyl you may want a Widget works knife that is spring loaded it it easier to set up on a cnc to cut part way through than that knife.

 

How about adding a "foot" as on a sewing machine?

 

thanks

thanks for all the info and the idea of the sewing foot,i also thought a glass cutter wheel might be an addon

 

better results withthe adjustment ot my toolpath

Sean Martin helped me understand and use a excel macro to adjust my toolpath to get the knife to orientate itself

donektools drag knife cutting plastic .03 thick - YouTube

this is the d2 drag knife which can cut up to .25 in material,it looks
like a simple concept but its not take it from me ,there is a lot of
programming thought went into the use of it ,as you need to run a macro
in excel to make some changes to your toolpath in order for the knife to
have its proper orientation

 

more cuts

still doing all sorts of cuts with the donektools drag knife,this time
i tried corrugated plastic from home depot cork and black sign vinyl

using the donektools drag knife to cut corrugated plastic - YouTube using the drag knife to cut corrugated plastic


cutting cork,and vinyl - YouTube using the drag knife toi cut cork and vinyl

 

I have a vinyl cutter, so I decided to try modifying a knife holder to fit in my CNC Router. I have a small precision machine with a water-cooled ER11 spindle. So I am limited to 9/32" max. My machine is mostly used for mechanical etching of printed circuit boards. But it's big enough to make signs and other wood projects.

I have had good luck cutting thin plastics and other material using the "D" type engraving cutters. I would be interesting to be able to cut very thin materials, like aluminum and copper foils.

The knives used in vinyl cutters are very sharp carbide mounted in cylindrical shanks. The end of the shank is pointed and fit into a triad of tiny ball bearings in the holder. A 2mm ID ball bearing also supports the body of the shank. So the knife can pivot freely, yet not move sideways.

I use Roland type holders in my vinyl cutter. You can buy the holders made in China for about $10 (including postage). The knives run about $2.50 each.

I modified the holder cutting a 1/4" shank and by moving an internal spring, I was able to spring-load the knife. Much like a scratch-engraving tool. So now I can control the downward force on the knife by how much below zero I set the depth. It works out that 0.0007" produces 1 gram of force. So I use a depth of 0.015" to produce 10gm of cutting force.

It cuts vinyl as you would expect, so I tryed it on some aluminum foil. It works pretty well. The CAM software isn't as smart as the vinyl cutting software I use. The vinyl cutting software understands the cutting edge is 0.25mm behind center (to make it track) and compensates for this so you can make square corners. I'll have to see if my vinyl cutting software could generate Mach3 G-Code.

 

interesting cutter

I also tried it with an exacto blade and tha worked ok too

 

I ordered a drag knife from Stupid Simple tools off of Amazon. I used it the other day to cut some thick card stock into a lightbulb shape. Vectric Vcarve Pro has a drag knife tool that creates the tool paths that cause the blade to go up when it turns directions just enough not to burger the paper and then back down. It works pretty well on my tests.

I don't have much more experience than this with it but it's pretty straight forward with the gadget creating the direction changes for a drag knife that is just being dragged around the cnc table.

 

JUST FOR THE MORE "FRUGAL" HOBBYISTS

Since my router's ER11 water-cooled VFD spindle can already provide rotation, I made a Working Drag knife by lathe machining down part of a USD2.95 Craftright Scapel knife holder that has an 7.8mm diameter Aluminum down to 6.8mm to fit a 7mm ER11 collet. Then cutting it to length.
The scalpel blade is soft for cardboard. So I just snap off one section of 18mm wide Olfa cutter blade, grind off part of it so that it will fit Craftright Scapel knife holder
and I have a USD4 dollar Drag-knife.

Works like a dream based on "caster-wheel principle" cutting packing cardboard.

Of course the THE SPINDLE must be switched off. when cutting cardboard

 

JUST FOR THE MORE "FRUGAL" HOBBYISTS - cont..


View attachment 403625

After I made above drag knife I found that the $5 DESIGN KNIFE is even easier to use on a CNC router as a CNC DRAG KNIFE. Just saw into 2 and mount with 8mm collet.

Design Knife - ZartArt Catalogue

Blade rotates 360 degrees to allow smooth flowing cuts. Ball head to burnish surface flat. Small blade for intricate and fine detailed cutting of paper, cardboa...

zartart.com.au

DESIGN KNIFE Blade rotates 360 degrees to allow smooth flowing cuts. Ball head to burnish surface flat (for folding). Small blade for intricate and fine detailed cutting of paper, cardboard, plastic. 3 spare blades included



Cut into 2 and you get a $5 CNC Drag Knife.