Hey, I know there are several rosin based printers on the market, but the ones that I have seen all use a projector of some sort to do the curing, I am curious if any one knows of a hobby grade printer that prints using a laser exposure rather than projection, it seems that the projector based solution would cost much more to produce, but that is just me.
My design thoughts for the mechanics:
Small voice coils with a relatively long through (like a speaker), D2A converter to apply an analog DC voltage to the coils, a mirror attached to a 2 axis pivot, a push rod attached to the x pivot and Y pivot. as you increase or decrease the x and y voltages you could “point” reflected laser position on the work piece.
I know that this is not the most robust system, nor is it the easiest to build, but I am just curious about opinions, And not to cite buzz words, but I believe there are mems that do such things for steerable lasers.
Laser light shows use galvos, which are more or less what you’re describing. They’re not super-expensive and are very accurate.
I suspect the reason these don’t exist is because most resins are UV cure, and UV lasers aren’t yet cheap.
Completely understandable, but If you do have a projector that is ~300 USD (guessing) in you BOM, I am assuming a UV laser and compatible galvos could be obtained for a similar or lower price.
Yes on the galvos. I’m not sure on the laser. The ones I have experience with are frequency-doubled YAG, where even the lasing medium and doubling crystals would exceed $1K, and xenon fluoride excimers, which are flat-out dangerous and need fluorine gas. There are UV diode lasers but they look like they’re in the $4K range for even 20mW.
Formlabs is using one of those old-school laser galvanometer setups rather than a projector. There’s also a project on indiegogo right now that uses a cartesian system.
Ahh. I guess that would answer my question, I understand why they are expensive, you cant see what you are doing and they could severely burn/ blind the user.
The plus side about UV lasers is they probably won’t blind you: they’ll trash the front of your eye, which can be repaired through corneal transplants and lens replacements. But I can tell you that UV burns are no fun.
Check out SLAMPS by Pryntech. The pryntech site has not completely launched yet but there was an indiegogo campaign for it. Until the site launches updates are through the Pryntech Facebook page.
I suppose the laser doesn’t have to move very fast, so there’s no real harm in doing it that way, but I still feel like it’s excessive when a few mirrors and dirt cheap servos could direct the beam as well.
@John_Bump prices hugely depend on what kind of UV the resin needs. I got a 100mW 405nm diode laser off of eBay for like $30, which I’ll try to use for directly exposing photoresist circuit boards.
@Nick_Parker That’s what I thought at first but there are a number of good reasons to take the Cartesian approach. Principally, you don’t get a decrease in xy resolution as you increase build area (as you do with projector or galvo solutions). Then there’s the greater accessibility to anyone who’s built a Cartesian FFF bot before.