Tuesday, November 16, 2010

Seed studio PCBs arrived

Well that took a while. But the PCBs made by Seeed studios arrived today. I didn't get a chance to populate them yet. Maybe I'll get a chance to work on that tomorrow.

Sunday, November 7, 2010

Plastic Engraving

I've done some work on the CNC machine yesterday and I was able to engrave some really fine text onto plastic. This is the first application for the machine that I have in mind. At work we make some hardware. I'd like to engrave the serial numbers in those cases. As you can see the engraving can easily be done at a lower laser power. Which leads me to the realization I need control over the laser power from EMC2. Maybe Drive4Die or Flexmod.

Also it looks like I'm going to need control over the Z axis to focus the laser on different height materials without having to refocus every time.

I've also noticed the machine isn't quite orthogonal, which is not too much of a surprise :). I'll have to work on that a bit as well. All in all it's looking very good.

Thursday, November 4, 2010

LPC-815 Diodes

The LPC-815 sleds and goggles arrived today. This guy made a great video showing you how to extract the diodes without harming them. Note that these are LOC (long open can) style diodes. That means the internals are not protected! Yikes. To prevent filings from getting into the diode I put some tape over the hole at the top. Then before I snap the thing open I carefully cleaned the filings away.

I was a little shocked when I finally got the diode out. It looked as if I had broken it. They really mean "long open can"! I Carefully placed the diode in the new holder and attached the wires. Negative on the top lead and positive on the left lead for this particular diode (YMMV).

The datasheet for this diode can be found here. Note that it says that 400mW is it's maximum and should only be driven this high if it's pulsed... Clearly the guys on the forums disagree. LaserPointerForums has this nice graph up. Also this thread has a good collection of the various diodes out there. This list says this diode should handle 350-420mA...

The goggles came today, both from Wicked and LaserGlow. Wicked runs a terrible operation they didn't even know the glasses had shipped and I ended up asking them to cancel the order. Now I have two safety goggles. I took the Laser Glow goggles home with me to test.

When I hooked up the new LPC-815 diode I thought I had killed it as I saw no laser light while wearing the goggles. I was expecting to see at least some dot of light. To my suprise I noticed that the laser WAS on the goggles simply blocked it fully. Tomorrow I'll try the Wicked goggles they are a lower OD rating. I would like to see the laser a little if possible.

Sadly I had forgotten my multimeter so I am not sure how much current I was putting through the diode but it's burning just fine! It went straight through the thin balsa wood! Maybe I can use the CNC cutter to make some airplanes :)

Things are looking good!

Tuesday, November 2, 2010

Parallel Port Interface PCB rev 2

With what I learned from revision 1 of the parallel port interface PCB I designed the new version. The goals I wanted to achieve compared to revision 1 are:
  • Better protection of parallel port.
  • Input / Ouput selection for bidirectional ports.
  • Actual working relay up to 2 amps at 12v.
  • Smaller (3.2 x 1.6").
  • More GND outputs.
  • Always on 5V output (VCC).
Features from Rev 1
  • Efficient Power supply (using switching power supply).
  • Easy connectors.
  • Reasonable priced components.
  • ESTOP relay shuts down 12 and 5v lines.
  • Integrated pull ups for input lines.

So the new revision does that I believe. I've ordered 10 PCBs from Seeedstudios. This means I'll have a few left over. If anyone is interested in them let me know. I'll have all the components as well.

The new schematic includes a 74hc245, a bidirectional buffer. The inputs have built in pull ups and protection resistors. And the relay switches both the 5v and 12v lines on and off.

Looking around on LaserPointerForums today I found this guys' build he has a very nice looking Laser CNC made out of metal.

Monday, November 1, 2010

Monday update

I didn't get to work on the laser530 yesterday due to Halloween. Hope everyone had fun, we sure did.

I canceled the order with WickedLaser for goggles today as they have still not shipped nor given me an order number. They really suck. Buyer beware.

I ordered these more expensive glasses from Laserglow. Don't forget to check laserpointerforums for discount coupons. I also ordered 2 open can red laser diodes from 20x speed DVD drives from Modwerx. They should put a bit more power out.