One of the things I would like to do with my machines is cut paper and cardboard, but I have no idea what kind of cutter would be used to accomplish such a task. Any high speed rotary tool would shred the material I would think. Anyone have any thoughts or experience in this at all?

Actually, I think most CNC machines that cut paper / cardboard use lasers for cutting and not a physical tool. Time to look at a nice laser and some front surface mirrors!

If you want to know what else laser systems can handle (rubber, acrylic, leather, etc), Epilog has a page for that:

http://www.epiloglaser.com/laser_materials.htm

There are a class of them that use blades to cut (you'll often find these in sign stores for vinyl cutting). I haven't actually seen one, but I imagine that the blade is mounted on a motor controlled axis so that it can rotate and stay in line with the cut. They are also referred to as cutting plotters.

I’ve seen the blade type. By memory I think it used a free turning blade, the direction of travel lined the blade up. Similar to the wheels of a supermarket trolley.

DJ

If you’ve got a high speed tool, try it out on some paper.

Another idea could be to use a set of those add-on nibblers for a drill, used to cut sheet metal.

Heck yeah, if only for the coolness factor -- FIRE it up =] From the minimag laser hack - it really wouldn't be to crazy hard to make one and mount it on the gantry.

http://www.instructables.com/id/Laser-Flas...Hack!!/

Not saying it'd be the most safe or best tool (homemade laser) but it'd be totally fun...might want to keep a fire extinguisher on hand though lol.

This might be BS in a can, but look into the "Hacked DVD-ROM Lasers". People out there have taken out the laser for a DVD-ROM and over powered them to pop balloons, set fire to a match, even inscribe images into wood.

The laser might not last long, but hey.... If you have what you need to make it sitting on a shelf in your basement, by all means try it!

Very common, called a "plotter" and used throughout the sign industry to plot vinyl letters. The 'knife' can be unpowered and trail the cut, or stepper/servo controlled:

Hi,

I'm looking to build a machine to cut up to 3 ply architectural chipboard for models. What kind of knife assembly do you know of for this application? A dual knife / pen plotter head would be favorite. It seems there's a lot out there for cutting vinyl but not so much for my needs. Lase seems to be the cutter of choice for this but I don't want to go there. Also the burned edge is something I'd like to avoid.
On that note what kind of a holddown would you consider for this kind of thing ? I'm thinking vacuum because of the force involved in dragging a knife thru chipboard but this would be my first cnc build and I think that's a bit daunting for a first time...

Thanks for your input.

JF

My extent of architecture was the general ed, Intro to Architecture class I took in college. Is the chipboard you're referring to similar to particle board or what exactly is it? And how think is the 3 ply? I'm just trying to get an idea of if this is like a wood or something like a poster board like material. I keep getting a mental image of trying to cut through particle board with a knife and thinking there would have to be a better solution. But I'm kinda ignorant to your field of expertise.

Same slang term but a different sort of chipboard than particle board (*) .... Think of a thicker version of the cardboard on the back of a legal pad or just like what makes up the inside of puzzle pieces or Monopoly game boards.



http://www.dickblick.com/zz131/15/


* FWIW my current favorite slang term for particle board is 'beaver puke' which I guess means that MDF would be called 'beaver poop'

Hey. Was away for a bit there. Yeah, you nailed it. Any ideas on cutting "beaver puke" : ) ?

My first problem is actually finding a tangential knife / pen cutting head. My school workshop had a Zund 1200 that we did terrain models on. Man, that thing went all day.
I'm also stuck on what kind of force to put behind it. Do the motors have to get bigger and could you get away with a belt drive ?
At this point I'm assembling / modifying the Solsylva belt drive table (for those who are familiar with the design) in Autodesk Inventor. Pushing a trim router around seems to be rather easy, relatively speaking, but for my application I have zero clue.

Thanks again.

JF

Hi JF, How is it cut by hand?

My experience cutting chipboard was with guillotine cutters for simple straight cuts and using dies made from steel rule for complicated cuts. This was about 20 years ago so probably not relevant today.

You can buy cutter knives for Zund and many other plotter brands, you can even buy complete blade holders. (http://www.smp-sign-systems.com/produkte/Plotter_Messer_e.html)

I was unaware of this until I took a wrong turn at a convention center but apparently scrapbooking has gotten way out of hand. There are several low-end diecutting machines like the Cricut, Wishblade, and others. I wonder about buying a replacement blade for one of these units and fitting it on a CNC machine. I suspect the blades are all small, simple drag knives. Maybe that would be enough for most applications, take multiple passes with a small knife.

Better would be to build a tangential cutting head using a stepper motor and a heavier blade

I wouldn't drop from consideration using a small router with a bit similar to what you'd use for circuit board work. That might be the easiest solution even if it's messy.

I thought this site had a nice list of Zund cutting options.

http://www.globalimaginginc.com/equipment_...ing/Tools.shtml

That's what I was thinking too. I bet an advantage to this method would be that you could make cuts that require very sharp angles or small radiuses. I'd imagine cutting a 1/8" diameter hole with a blade would be difficult.

If the board is paper-based, router bits will fluff the edge.

I wonder if there's a more router-friendly material that could be used instead of the beaver puke. Maybe some of that "machinable wax" that everyone's talking about?

Yes, and is the world really ready for a robotic fluffer? On second thought that might be quite the seller!

i just happened across these paper cutters:

www.craftrobostore.com (from www.graphtecamerica.com)

also, here are some craft robo replacement blades and graphtec replacement blades

maybe that'll give some idea as to cutting paper using CNC.

The normal tool used to cut paper and cardboard using a CNC is a blade. Not a rotary blade, but a blade like an Exacto blade or similar. In some cases this blade is just dragged through the material. In most cases the blade is fitted to an oscillating or reciprocating tool. This is like a miniature jigsaw with a depth stop to ensure the blade does not go too deep into the material being cut, or the substrate. The material is normally held down by vacuum on a vacuum table. The blade is steered by a tangential steering system into which the tool is fitted.

Some papers or cardboards have a lot of rag content, or if they are recycled, they can have a lot of clay. These all blunt blades or cause the blade to pick up "swarf" on the cutting edge. If the blade is a plain drag blade, then this will start tearing the material very quickly. That's why a reciprocating blade does much better on average, because the reciprocating action is exposing a more or less fresh edge of the blade to the material.

The type of blade does vary. For some materials, you can get away with a surgical scalpel blade, and others require something a little stiffer. Generally a sharper, thinner blade will perform a lot better than a stiffer, thicker blade. For suitable blades, have a look at art shops, or people like Swan Morton.

There are only a handful of people who manufacture machines specifically for cutting cardboard for sample making or short run boxes. So you'll find that a lot of the blades out there which fit automated cutters are not going to be suitable.

HTH

JC