My Cheap engraving with Diode from Cd_burner (videos)

[Fr3d-]

I put an IR Laser from CD Burner on my CNC.

I did this CNC on my vacation using Step motor from NIMA old printers and othes stuffs.
Normaly I use with a dremel (similar) to milling acrylics.
There ar others videos in my Youtube Channel.. take a look.

The diode runs at +/- 105 mA.

The power output of diode laser (no matter the color) is P=I*V as some ppl says ?
I don´t belive because there is some heat loss. Right?

Videos: U-tube

YouTube - IR Laser (from cd_burner) CNC 2

YouTube - IR Laser (from cd_burner) CNC 2

YouTube - IR Laser (from cd_burner) CNC 2

YouTube - IR Laser (from cd_burner) CNC 2

[MacGyver]

Originally Posted by Fr3d- The power output of diode laser (no matter the color) is P=I*V as some ppl says ? I don´t belive because there is some heat loss. Right?

P=IV is the standard equation for power in general, not just diodes. That does not mean, however, that all of that power is going into the material being lased. In fact, that laser diode is only a few percent efficient, so you probably only have 5-10% of your power being turned into light. I can't see what kind of optics you have set up, but obviously it's enough to focus the spot small enough to burn (it's all about power density, not just power).

You're probably in the 800-900nm range as far as the wavelength goes, right in the area of YAG lasers.

[BigMike4u]

Neat as heck. Please post some more details on how you did this.
Mike

[Ferny]

I hope you have laser safety glasses on! Since the laser has enough power to melt plastic I think it could blind you easily too! Don't forget reflected light also.
Lasers can blind you easy!

The DVD drive should have had a yellow sticker stating the class of laser, the wavelength, and the power of the laser diode in milli watts (mW). Do you remember what it is?

Pretty neat project.

Ferny.

[wwendorf]

That's in amazingly awesome!!! Please, can you post details/plans on how to build one of these????

Thanks,
Wade

[Fr3d-]

wwendorf: What u wanna know ? Is about CNC or Laser?
The CNC is simple, all u need you find here in this forum... and about the laser, you find here in this post: http://www.laserpointerforums.com/fo...num=1185701612


Ferny: "I hope you have laser safety glasses on!" - I´m sorry... I´m not. hehe
But I take care. At leat I use a sunglass. Better than nothing, or not...
I´m looking for one. Do you know a good site ? Or only ebay ?
About the yellow sticker, I will take a look after.

[wwendorf]

No, cnc i'm good with. Electronics are a bit of mystery for me, but I can build then from exact plans. I looked over the link you posted, but i'm afraid my knowledge is not enough to attempt the build of the laser driver myself. Do you have to build optics as well??

Would you considering building one for me, and if so, how much???

If you aren't interested in building one, would you possibly be able to post some sort of a build log or step by step instructions on how to make a laser driver on this forum?

Thanks much,
Wade

[Fr3d-]

wwendorf: To your luck, I found this video:
http://www.metacafe.com/watch/1011559/diy_how_to_make_a_laser_diode_driver_circuit/
That´s the same circuit.

Fred.

[wwendorf]

Nice! Thanks Fr3d! I'm going to build one of these drivers. That video really explains a lot. Much appreciated!

Wade

[Mr.Chips]

A really first rate job on the diagrams, you covered all levels of skill.

Everyone needs to remember the dangers of even low power lasers. WEAR protective eye coverings.

[Mr.Chips]

Originally Posted by Fr3d- I put an IR Laser from CD Burner on my CNC. I did this CNC on my vacation using Step motor from NIMA old printers and othes stuffs. Normaly I use with a dremel (similar) to milling acrylics. There ar others videos in my Youtube Channel.. take a look. The diode runs at +/- 105 mA. The power output of diode laser (no matter the color) is P=I*V as some ppl says ? I don´t belive because there is some heat loss. Right? Videos: U-tube YouTube - IR Laser (from cd_burner) CNC 2 YouTube - IR Laser (from cd_burner) CNC 2

What is the material being cut?

What would be required to focus the beam to a finer point?

I can see this being a very nice woodburning tool for putting designs in wood.

Good job.

[gn0stik]

He doesn't say this in the video, but it's important to make sure you have the polarity of the diode correct. The strip on it indicates the cathode side, and it should be pointing toward the positive side of the circuit. The capacitor has a stripe on it. This is the negative side of the capacitor. It should be pointed to the negative side of the circuit. The resistors are 1/2 watt 10 Ohm resistors, and they are wired side by side (parallel). All of the parts in the video can be had from radio shack.

The diagram that he shows at the end of the video is mislabeled. It calls for a single 4 ohm resistor, the pins of the LM317 are ordered wrong, and it uses a 100 ohm pot. This will work as it is drawn but if you don't know electronics it can be confusing. Use the one, I post below.

When soldering on your laser diode, it's a good idea to use a copper alligator clip at the base of the pin when soldering to sink some of the heat away from the Laser diode. Too much heat is a MAJOR factor in killing these things. It's also a good idea to get a tiny glob of solder on your wire BEFORE hand. This is called tinning the wire, and helps you solder the wire to the diode faster, reducing the amount of time to solder it and hence heat buildup on the diode itself. It's also a good idea to do the positive one first, let it cool then do the negative one.

Now on to the placement of the components in the video. He put the resistors in before the potentiometer, which is wrong. The resistors are there to protect the diode in the event that you turn the resistance all the way down, and hence the voltage all the way up with the potentiometer. The circuit will still work, just differently. The way he has it set up, the amount of voltage the pot sees is lower, hence the amount he's controlling with the pot is lower over all. This will work, but the total amount of voltage is still high enough to fry the laser diode so it's not really the best way.

About the potentiometer. It does not matter which leg you connect to the common ground pin on the pot. It will simply change the direction that you have to turn it in order to turn up the resistance. It's always best to check it out on a multimeter on the Ohm setting. Wall mart sells cheap, good auto ranging multimeters for general purpose electronics in the automotive section.

I have labelled the diagram at the very end of the video for you to use.

Just a quick note on this whole project, always watch your voltage, and heat when working with Laser diodes. Take all precautions. Always drain your cap, etc, etc.