Grad Student Invents Cheap Laser Cutter

An anonymous reader writes "Peter Jansen, a PhD student and member of the RepRap community, has constructed a working prototype of an inexpensive table-top laser cutter built out of old CD/DVD drives as an offshoot of his efforts to design an under $200 open-source Selective Laser Sintering (SLS) 3D printer. Where traditional laser cutters use powerful, fixed-focus beams, this new technique dynamically adjusts the focal point of the laser using a reciprocating motion similar to a reciprocating saw, allowing a far less powerful and inexpensive laser diode to be used. The technique is currently limited to cutting black materials to a depth of only a few millimeters, but should still be useful and enabling for Makers and other crafters. The end-goal is to create a hybrid inexpensive 3D printer that can be easily reconfigured for 2D laser cutting, providing powerful making tools to the desktop."

Comments

Dual Use?

[WrongSizeGlass]

The end-goal is to create a hybrid inexpensive 3D printer that can be easily reconfigured for 2D laser cutting, providing powerful making tools to the desktop

3D printer and a laser cutter? I'm no office machine expert but I don't think I want a printer capable of transforming into a laser cutter ... I've seen the Twilight Zone and this doesn't end well.

It will never sell.

[seeker_1us]

Why would anyone want to cut a laser?

Re:It will never sell.

[TubeSteak]

Why would anyone want to cut a laser?

So it'll fit better on small sharks?

Re:It will never sell.

[derGoldstein]

Well yeah, but they're each only half as long.

Interesting note

[oldspewey]

His roommate's PhD project is the inexpensive cloning of sharks.

I'm not sure I like where this is headed.

I was not aware what RepRap was

[cortesoft]

http://en.wikipedia.org/wiki/RepRap_Project

Cool. I want a self replicating replicator!

Re:I was not aware what RepRap was

[Trepidity]

I'm afraid your only choices are zero or infinite self-replicating replicators.

Re:I was not aware what RepRap was

[Anonymous Coward]

I've met the RepRap team and I can tell you the one thing they are best at (and it appears slashdot are helping them replicate) is hype and self publicity.

The RepRap machine is basically a cheap plastic printer / rapid prototyping machine which is an idea that's been around ... at least 10+ years before they started. The only component they can manufacture are the plastic bits. Have a look at the photo and see if you can spot the plastic bits. I'll give you a hint, they're not the metal frame, or the wooden base, or any of the active / electrical components. And it goes without saying that, ofcourse, you have to assemble the device it's "replicated". I recall someone asking them what percentage of the device they could 'replicate' and after lots of 'vision' and 'this has great potential' we eventually managed to get a figure of 10%.

Rapid prototyping machines you could build at home - kinda cool but not new. Calling it 'self replicating manufacturing' - shameless publicity whoring.

Re:As opposed to doers?

[AdamHaun]

It's a reference to the subculture embodied by this Make.

Public School shop classes.

[FrameRotBlues]

IMHO, this is the kind of inventive tinkering that should be pushed forward in today's schools. It takes a lot of different skills from across several disciplines to be able to crank something like this out, but once you see it, you realize how simple it really is. It takes imagination and perseverance as well, and that's hard to teach.

I don't mean to start a "Public schools are apathizing our youth!" thread, but I wonder how many kids would really enjoy classes geared towards making useful projects out of surplus crap - a combining of wood shop, metal shop, and electronics classes.

Re:Public School shop classes.

[Dunbal]

By necessity the school has got to gear to the slowest.

      And that's where everything starts to go wrong. Instead of encouraging the stragglers to catch up, everyone is forced to slow down. In this environment not one slow-poke will make an extra effort - why should he? Whereas more than one above average intelligence student will get frustrated and/or bored and stop paying attention. Only the truly gifted come through such a process unscathed - but because they don't need "school" anyway. Put them next to a pile of books and provide a mentor to answer the occasional question, and they're fine in ANY environment. They live for learning and you can't take it from them.

Cloth?

[WindBourne]

Seriously, something like this could cut patterns CHEAPLY on cloth. Think of it as a stamping machine.

Actually optical choppers are very useful

[caseih]

Warning: Science content.

Several labs in my Uni's Chemistry Department regularly employ LASER choppers, if not "cutters". Simply stick the disk with the slits you want (to set the pulse duration) in front of the laser and set the motor to the desired RPM. That's how they get he pulse durations and frequencies that they need for their experiments. One could also use liquid crystal to turn the beam on and off rapidly. Come to think of it, I have no idea how a CD or DVD burner controls its laser. Maybe the laser can be turned on and off fast enough.

Re:Actually optical choppers are very useful

[TubeSteak]

Come to think of it, I have no idea how a CD or DVD burner controls its laser. Maybe the laser can be turned on and off fast enough.

The laser is continuously* on and usually at a fixed distance.
The laser head can move up and down if it needs to change the focal length to try and re-read errors.

The spinning disc also provides the time + convection for heat to dissipate and not melt the plastic.

*or not depending on whatever caching mechanism the drive has...
which isn't the same thing as saying it can't be turned on/off rapidly, just that there's no need.

Re:As opposed to doers?

[TheLink]

Yeah Shai-Hulud's been around for a while.

Re:MOAR POWER!

[Jedi Alec]

I'm going to be up front and honest and tell you "I don't know".

Ok, that's it. Please hand in your Slashdot ID on the way out...not knowing something is one thing, but actually admitting it?

Shame on you sir, shame on you.

Re:MOAR POWER!

[Khyber]

Yes, they are, as blue is a higher energy-potential.

200mW 405nm Laser vs 350mW 630nm laser - blue laser will win every time.