We need motion
If you want to make a lasercutter, then you have to be careful when designing a motion system. Your laser tube is a heavy and large object which you normally want to mount in a fixed position
If you look at the diagram on the right, the you’ll see the laser tube in the back. The tube fires a beam to the left and that beam hits the first reflective mirror. It then goes to the 2nd mirror and from there on to the laser head. Inside the head a third mirror reflects the laser beam downward through the laser lens and onto your workpiece.
The gantry system has a few requirements.
- It should be perfectly square
- It should move freely without a lot of friction
- It should be low of mass
For the LaserBeaver laser engraver, I have decided to test out the CoreXY motion system.
In a normal XY-system you have 1 stepper motor controlling the Y axis and then another one controlling X. But the X-motor is moving on the Y axis.
This is not BAD, but it has some disadvantages. As you can see the whole gantry system is quite big. There is a stepper motor mounted on the gantry (so it moves too) and you have to power that motor, so you’ll need some kind of energy chain (drag chain) to make this happen.
Because of the larger weight and the need for drag chains, this kind of motion system is not capable of running at super high speeds (the extra mass makes it difficult for the motors to accelerate really fast).
Now I hear you thinking that you don’t need all that speed. Typical cutting is done at relatively slow speeds. And you’re right… for cutting. However, you certainly need speed when you want to engrave photographs.
Have a look at this youtube video (not mine)
You’ll also want a fast laser head if you want to cut out greeting cards out of cardstock. All these small moves take a lot of time if your laser head is not able to move fast enough.
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