Hi all. At work I would like to bring the production of our shipping cartons in-house in order to create custom packaging for each type of product we build in order to reduce the carton size and reduce shipping costs. I think I can do this with a Lowrider but I’m hoping you can help with a few questions?
I am hoping to use a drag-knife for cutting cardboard as it will reduce complexity compared to having a stepper-mounted cutter. The drag knife height would be controlled by the Z axis.
In the future I would like the ability to use a stepper motor on the gantry to rotate a non-dragging tangential knife
It looks like this has been successfully implemented on an MPCNC:
(I can’t link)
I am planning on using a relay to control a pneumatic cylinder for creasing the cardboard. This means I can have the Z axis raised (the knife not cutting) and use the downward force from the cylinder to press a creasing tool into the cardboard.
The cardboard we’re planing on using is a twin-cushion with a nominal 7mm thickness, and the uncut sheets need to be 1800x1200mm
We’ll have approx 12 different cut files for different types of packaging.
I would like to be able to control the LowRider plus 1 additional stepper and ideally up to 2 relays
I’m good at the mechanical side but less experienced on the electronics and firmware, although I can write functional python code.
Do you have any comments about whether the LowRider would be good for this purpose?
Can you suggest which control board which is best suited?
Cutting corrugated board is doable for very small runs, but can become overly time consuming pretty quickly for larger quantities. The “big boys” do it by die cutting.
@niget2002 's suggestion of laser cutting is definitely an option to consider. If using a diode laser you’d probably want a very powerful one, otherwise you’re probably talking about a pretty powerful CO2 laser.
Concerns here (re. laser) are fume management and size. You’ve indicated a pretty large cut area is needed (1800x1200mm). A powerful diode laser attached to a LowRider means accommodating the size is doable, but wrapping a large LowRider in an enclosure to capture and evacuate the smoke and fumes, would be its own challenge. By comparison, a factory built CO2 laser with its own enclosure, is not usually that large. I have a big one (100W CO2), and its cuttable area is only 900x600mm.
@DougJoseph We’d be doing about 4 or 5 per day and a cycle time up to 45 minutes is fine (it will take more than 45 minutes to build the things which go into the cartons) so no rush.
Our current cartons are die cut off-site and are large enough to fit all our product variants which means we’re often paying to ship air. We’re hoping to bring carton production in-house to reduce delivery time and packing + shipping cost. The end goal is to be able to make one-off cartons which are only-just large enough for the products so having a whole lot of massive dies isn’t practical.
I was hoping to avoid a laser…I’ve got a small laser and it makes a helluvalotta smoke on cardboard which I really didn’t want to deal with, plus the non-zero fire risk
It would be as good as any other CNC (until you entered the very high price range). No one has done this, especially at production. So you will definitely be taking a risk and you’ll be problem solving and learning along the way. We can help wherever possible, but we aren’t in the room.
The jackpot is very flexible, easy to configure, and runs a more standard CNC firmware (grbl compatible).
If you hand coded the gcode (or hand edited it) tmfor each custom box size, is that arduous? Like, do you have <20 shapes you want or is it hundreds? I think getting something working will be possible. But I imagine running back into CAM every time you need a box would break the labor budget. If you could do a dozen or so gcode files you knew worked, and just crank them out all day, that would be effective, I think. Especially if you added a tangential cutter on an A axis (which you may have to for 2 layer 7mm cardboard). Just manually adding in the A axis might be easy enough to not try to solve the CAM problem.
@MalaBlanca, got it. That quantity and rate sounds doable.
You can certainly accomplish this with a spinning bit in a router. I’ve cut corrugated board with a 1/8 inch end mill. This approach does produce fuzzies along the edges that can easily be knocked off with an orbital sander. This approach would certainly allow you to meet that rate and quantity goal.
An approach of using a drag knife type blade likely is doable, and it may just need some experimentation to find the right steps regarding depth of cut and speed, etc.
It’s almost certainly doable with the tangential type blade. Again it would take some prep work and some trial and error to get everything just right.
I hope you will keep us posted and provide photos and/or video of your journey!
And although, of course, it’s correct to say the risk of fire is not zero, technically the risk is above zero any time electrical equipment is being used. Regardless of which method is used, it should not be left unattended.
The methods that involve dragging a knife blade are probably the lowest risk of fire, I would think.
Just spitballing. I think laser would probably be the most reliable method. The risk of fire is probably highest when you’re figuring things out. Once you have reliable speeds and feeds, it would probably be a fairly quick method.
But then I started wondering if one could build a belt feed. Activate the belt, feed in cardboard until it breaks an optical sensor, cut, then turn the belt to dump the box parts and load the next sheet.
Is a needle cutter out of the question? I’ve never used one but when you asked about scoring that was the first thing to come to my mind. Has anyone here tried cutting cardboard with a needle cutter? @dkj4linux
I used to “torture test” my sturdier needle cutters by trying to cut cardboard and coroplast. Thicker, heavy-duty, cardboard and coroplast never cut completely… between ribs usually okay, less completely across ribs, especially in coroplast. Thinner (~3mm?) corrugated cardboard cut pretty readily…
I regularly make templates and fit-tests with lasercut cardboards
It’s fast , cheap and easy
The main advantages are:
Can re-use the LR3, or build a New dedicated machine
Quite cheap
Very simple process, no finicky setup or adjustments
You have to take care of the smoke though…
The way I see it, you could build a second smaller lowrider on the lower shelf of your existing lowrider table
This would provide an easy structure for an enclosure, add some red plexiglass and you’re good to go
Having both machine on top of one another would probably help streamlining the production process too
