Question on Difference between Laser Cutter and 3d Printer

At the most basic, both systems utilize a mechanism to move their (X,Y) directed coordinates above the build volume defined by the Z axis interval. Laser cutters as well as other directed-energy systems (laser sintering, etc) differ in that there is no end effector that much be moved, only optical guides (mirrors) that deflect the laser's output downwards to the affected target. A 3D printer must provide feedstock (typically thermoplastic filament in FDM/FFF 3D printers) to the hot end attached to the end effector, which is moved about at the end of a constrained mechanical system that can define the (X,Y,Z) coordinates - Cartesian, Delta and Polar systems provide this mechanism with different movement geometries to achieve similar results. A laser cutter needs only to move a mirror into place along one vertice of the movement (such as: along the X axis) and then a second mirror at the terminus of the second vertice (such as: along the Y axis) where it directs the focused illumination down onto the target location. The requirements for feedstock and management of the extruder's hot end affect the structural qualities needed in the mechanical systems for each. The same mechanism can provide both additive and subtractive manufacturing mechanisms like many of 3D Printer/mini CNC variations. You could use the same type of stepper motors and stepper drivers to control both a laser cutter's target positioning and a 3D printer's extruder hot end, although for simplicity I would stick with a Cartesian model for the 3D printer in that case. Does this help answer you question?

Kirk

Are you describing a professional laser cutter, or more like what you'd find on Instructables where you would use a less expensive laser? That almost sounds like the laser is stationary while you would use mirrors to direct it- is that true?

I was describing a commercial system we use on campus. The emission tube is almost a yard long itself, and is kept rigidly protected during operation, not moved above which could result in damage to the laser tube. Instead, it remains steady and the mirrors are moved along the two axis vertices to relay the laser's power to the final focusing optics just before being incident upon the targeted material. This one is lighter weight, so uses a moving trolley on linear bearings to transfer the mirrors along each path, but I have seen heavier systems using linear screws for the same purpose.

Kirk

You are awesome. That makes sense! I was wondering about that. I imagine the lasers off of those are much stronger then the laser diodes I was thinking about. Thank you again, I really appreciate the feedback!

Glad I could help, and good luck with your own designs! There are a number of different "DIY" type builds you can attempt using lighter-weight components. Lower-power laser tubes also mean less cooling, etc, so a simple laser diode from a Blu-Ray player can be handled with a simple thermal heat-sink, compared to commercial systems that may need fluid-dissipation systems and the like. Sometimes scaling up means the plumbing gets much more complicated, after all!

Kirk

On the software side, I use inkscape for laser cutting and openscad for 3d printing.