Drag knife for corrugated?

Hello - I’m wondering if anyone is running a Lowrider with a drag knife for cutting corrugated cardboard?

I’d like to use it to make packaging, so it doesn’t have to be mega precise, but just wondering if one of the many blade style drag knives out there would work well enough in the thickness of corrugated you’d find in USPS flat rate boxes.

Thanks

 

What about one of those 2.5W bangfood lasers?

The knives I’ve seen used for corrugated vibrate. Well, actually they oscillate, but you can’t really see the blade move, it’s like half a mm stroke. A regular drag knife might work though, you’d need to put a pretty good down force on it though.

Donek Tools has a heavy-duty drag knife that uses standard utility blades…

https://donektools.com/product/d4-drag-knife/

Pretty pricey ($249 IIRC) but well made and able to cut thick (1/4") materials like coroplast and corrugated cardboard. The D4 model has a 1/4" shank that chucks up in 1/4" router collet.

I was gonna mention this exact tool! There are printed variations of it on thingiverse, but I do not know how they compare to the donek.

Printed version would be a good start then. If it works, but breaks after a while might be worth the price of the real one.

That’s my worry…the downforce being sufficient with the Lowrider structure. Sometimes the cut would go all the way through, and sometimes just half way, depending on the fold/cut.

Maybe the idea of a laser is better…sounds like more fun anyway :slight_smile: I’d imagine I could vary the output power to cut half/full way?

 

Corrugated is funny with lasers. The corrugations can cause laser focus issues, which usually ends with fire.

 

If you’re using the spindle mounted drag knife, I’d think it would have enough weight behind it. The vibro knives just help with tight radius cuts. Like the half lap grid cuts for making bottle separators.

Check this post to see cutting IIRC 3mm corrugated cardboard with a 2.5 - 3.5 watt Banggood laser…

https://www.v1engineering.com/forum/topic/mpcnc-inspired-corexy-laser-engraver/#post-36423

It’s not terribly fast but it is pretty clean. The secret is to have good airflow to clear smoke and suppress flames – I think a shroud of some kind is crucial – and absolute BEST FOCUS to cut in one pass. This was with focus on top of material (using Ryan’s laser focus script) and 100 mm/min at full power.

This thread also has some good information for cutting cardboard with a laser… IIRC I was able to double the speed to 200 mm/min for clean through cuts with the newer shroud

https://www.v1engineering.com/forum/topic/laser-cutting-carboard/

– David

 

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