Hello,
It has been a long while… In the mean time I have been busy with changing countries, colleges… life in general…
Quite recently I lost every mean I had to take photos so this post doesn’t have any image that is mine but all the merit goes to their creators/owners. Now to the next hack/build/project.
Everyone that knows me knows that I like lasers. Lasers are way too cool and dangerous not to like them 
I have this beautiful 445nm 1W laser that I showed you in the older posts and now I want to control to draw light shapes for other projects, so I started searching for ways to control lasers properly.
One of the ways is like I tried before with my old RepRap Mendel moving the X and Y axis. Unfortunately I don’t have access to it now and it had some structural problems that made it imprecise.
Another way to do it it to control the reflection angle of the lasers in 2 mirrors for X and Y. This method is much faster and is the one used in most laser applications that don’t require big actuation areas.
For now I just want to be able to control it and get the desired 2D shapes independently of scale so I will try this mirror angle thingy… I noticed that someone tried to use this technic for a laser sinterer(that is one of my intended uses) by using stepper motors, but I would say the results fall short from my expectations. Another way to approach this is by using Galvos instead of steppers motors, these are high speed motors that have very little torque. There is an “old” fantastic project on how to build one by ChaN.
ChaN’s build results look fantastic so I decided to go his way and try to step it up a notch with nowadays more readily available resources.
The next posts will show my developments and hopefully good results in developing 2 (X & Y) galvos to control a laser with great speed and accuracy.
The first step is figuring out what can be improved. This is ChaN’s Galvo:
It looks a bit rough but it actually has some pretty good results. It is also very small 4 cm long and this is important because these motors have almost no torque but really high speed this makes the weight of the shaft one of the most crucial parameters that we should try to improve.
Number 4 is his shaft:
It is made of a carbon steel shaft is got from another motor and in the center a magnet bonded and later shaped with a grinder. The carbon steel insures some stability that I will try to discard since I’m going to try to build it even smaller and lighter so my choice went for a carbon pipe from Conrad (The thing is stronger than it looks). For the magnet I got my hands in some of these tube magnets (Magnetized across the diameter).
Before I start putting things together I’ll make a 3D model of my goal and use it to print a case for the motor instead of building in the prototyping board ChaN used and that will be my next post that will be coming still this week (maybe even tomorrow).
Side note: as I was searching for the items to use in this project I noticed that they are available in smaller sizes both the magnet and the rod so I set as a goal to make it even smaller in a future iteration.
Reonarudo and 
Jonas O are discussing. 
Daniel are discussing. 
JL Arnal are discussing. 
) to keep the circuit and the laser cool and it seems it worked. Ate least this time it didn’t auto destruct from the laser heating and helps keeping the smoke away from the lens.
Hi!
I’ve been looking into using UV-lasing for exposing presensitized PCBs, both by using standard 2-axis CNC and the use of galvos, as you’re getting into here.
The obvious problem with using galvos is focus, you need a motorized optics, and preferably a special type of collimating lens (can’t remember specific name) to direct the focal point uniformly onto the PCB.
So I settled with trying to making a generic RGB projector, using pre-made scanners – hoping to come back to custom built galvos when I have sufficient time and better knowledge of what I’m doing!
Going back to the CNC method – before I invest more thought into it I’d love to have your opinion – would you recommend using paint/etch/acid or pre-sensitized PCB/etch/acid? Or to abandon the idea and revert to more…conventional methods?
As a side note, I’m in the process of tuning the machine to be able to mill tracks directly. However, so many variables and microscopic error tolerances makes it slow – not impossible – to find a working setup.
Awesome to read about your work. Thumbs up bigtime!
//JonasO