This Fail of the Week is really only a failure because of the standards to which [eLabz] holds himself. The rig pictured above is a laser cutter built out of DVD drive parts. It goes above and beyond most of the optical drive CNC projects we see around here — it actually makes cuts! But [eLabz] looks on it as a failure because the steps of the driver motors are visible as jagged edges in those cuts. We see this more as a pausing point in the development process before the next refinement is made.
First off, look really closely at the assembly to the left. This is responsible for the X-axis and a very keen eye will have noticed there are two sets of DVD lens sleds stacked on top of one another. This design allows the laser to travel twice as far (a whopping three inches in this particular case). Here’s a rendered video that was made to help visualize how this would work before building it:
You have to admit this is pretty sweet! But renders are nothing, it actually exists too. The double x-axis and the single y-axis are both used to move the laser diode, meaning the work piece is stationary. [eLabz] mentions he thinks this presents a problem because there is some play in the system. In addition to that the test piece he ran clearly shows the point at which each step of the motor was taking. The line is jagged, but with stepper motors it should be possible to have much better resolution. Right?
So where do think he went wrong? In looking back he figures he should not have used DVD parts as the tolerances just aren’t where he needs them. But he’s come so far we want to know how you’d take it the extra mile to achieve the smoothest cuts possible. Join the discussion by leaving a comment below.
But first, check out a close-up video of the tandem x-axis sleds running:
Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.