Arduino Based CNC with a conveyor

Hi. I am trying to figure out if there is a posibility to use arduino for a laser cnc cutter with a vonveyor so when it finishes cutting all the pieces in the cutting area to advance the conveyor and continue cutting the next pieces (if possible also the pieces that did not fit on the first cutting area, to be continued in the second cutting area). I've searched a bit over th einternet, but did not found any usefull info, if this project can be done. Depending on the possibility of this converyor table i have to design the CNC

4 axis grbl for machine control will do. 3 axis for laser, 4th for conveyor. You'll just need some gcode preamble to clear off the work area.

any material handling is completely separate from the Laser cutting

creating a table that moves the parts could be by rollers, moving pins or overhead magnetic crane.

aligning parts that are too long should also be a matter of mechanical design.
either cut some reference holes before you move the sheet, create some alignment point(s)
my PCB etcher uses 2 pins. just flip the material align the pins and presto, other half. easy to do in CAD for the cut.

The problem I see is that of small parts being cut or cut out might be too small for the transport system to move.

How do you stop the laser from cutting the conveyor belt?

MorganS:
How do you stop the laser from cutting the conveyor belt?

One answer (out of many, I suspect) could be to have an arm that sweeps the cut parts off the cutting table and onto the conveyor belt.

…R

ty all for the sugestions. Actually i am trying to do something that resembles Lectra cutting machines, but with laser. So the conveyor it will have the material that is to be cut on it, and as it finishes with the first area, to advance the conveyor so a new no-cut area is next. i think that is the biggest chalenge: how to restart cutting from where it left off. Lets say my material is 8m long and my cutting area is 2m long. I intend to use a laser cutter and the conveyor will be build by a flexible metal web.

I don't know how you prepare your cutting stage, but there is software out there for $$$$ that does exactly this. You can write this sotftware on your own - isn't that hard, if your preprocessor emits gcode. Or you can pay somebody to write the software for you - in this case I would strongly suggest to move from grbl to linuxcnc. You can drop me a line on this, if you need assistance.

It is going to be difficult to get consistent movement on the conveyor. It's going to be kind of big and chunky moving 8m long pieces of steel and that means it probably can't stop within a milimeter of the desired location. But your laser beam is probably less than 1mm wide, so it needs to find the end of the previous cut to higher accuracy.

You are going to have to invest in some machine vision so the laser head can be recalibrated to the new position of the material after each conveyor move. I've seen some impressive stuff done with $10 cameras on home PCB pick-and-place machines.

A quick glance at the Lectra website leads me to guess that you can't buy any of their machines for less than $5000 USD. Matching that quality with $30 worth of Arduino parts is going to take a lot of work on your part.

Yes , you are right. I want to build a Lectra replica, based on Arduino .
We own a Lectra machine, the problem is that the spare parts are very expensive and they have a short period of service life time for some of the parts. My goal is to have at my disposal all the parts for the future cutter. I do not mind have 100 Arduino boards interconnected in order to achieve my goal. Lectra cutter has way to many consumable materials: perforated paper, blades, sand paper belt for the blades and the plastic foil for the vacuum. I am not trying to replace a 5000$ machine with a 300$ one . I am aware it will cost more, but since it will be built by me I will know what to change and what to do, since Lectra are very closed ( a quick search u will find out that u won't find nothing about Lectra, as service manuals, errors, nothing...)

To my mind there are three layers to the design of any computer controlled machine.

  • First there is the mechanical system which must be strong enough, precise enough and capable of doing the necessary motions.
  • Second there are the actuators that cause the mechanical system to move and sensors to detect things.
  • Third there is the computer control system that obtains inputs from sensors and instructs the actuators to move.

The design process obviously needs to keep all three layers in mind, but I reckon the first layer will be by far the most complex and the most important. Without it nothing will work. On the other hand, with a suitable design for the first layer and a suitable set of actuators and sensors the computer side should be straightforward, even if not trivial.

Put another way - get the mechanical system figured out first. Then select and program your controller.

…R