This Project Actually Completed January 2009
This is a revision of the aluminum heat sink we have been using for the the 3 watt tricolor LED control boards. These will serve as generic tricolor led drop in modules for future art pieces. The control board has 3 FET control channels 1 for each color and a microcontroller, for the brains. On the top sits the LED nestled in its heat sink to keep it cool. The whole assembly in its present incarnation looks like this.
This project was actually completed in March 2009, WOW!!!
Our house was built in the 30’s and some some of the fixtures are still from that time period. One of the rooms in our house had and old bare bulb in the ceiling, it used to be switched by a pull chain but that had long since broken. The only way to turn the light on was to reach up and screw the bulb in, and reverse the process to turn it off. Not so fun!
After removing the old fixture, I realized the ceiling tiles around opening were very tattered, cracking and peeling back. The base of my new light was not large enough to cover the area, and the ceiling tiles were way to old to be replaced. Thinking about some way to cover this area before I put up the light, my brain saw the opportunity to use the CNC machine. Aha!! I had figured out a way to spend the Saturday playing with the machine in the guise of working on the house, brilliant. 😉
Recently found this really interesting utility for Google Sketchup. Its called SliceModeler, it gives you the ability to slice up your sketchup model into pieces and then make them flat for cutting out of sheet material. Great idea and concept for me.
A long while back I put together a headlamp using a luxeon star 3 watt LED and some driver electronics from Ladyada. Everything worked fine and life was good. Recently however, when I reached for my trusty friend I found the strap dangling loosely. One of only a few plastic pieces on the light had snapped.
Originally, when I made the light, I drew the plastic bracket in a 2D CAD program and then printed onto paper, traced it onto plastic and then cut it out with an exacto blade. Now times have changed and I wanted to use the OZO to make another one.
Ozo cut if an OZO would cut wood!
Had a bit of time to fool with the machine over the Holidays and decided to try out the new hold down techniques and cut some thin wood. It went pretty well, all thing considered. I cut what appears to be thin mahogany surfaced plywood sourced from the local mantle shops bin.
Out behind the local Pier One and leaning up against the bin was this really neat looking T slot material. Not real wood mind you, but still fairly stout and it should work for the kind of small stuff that I have been cutting. This is what it looks like installed.
The opposite of remote control.
So far, considerable time is being spent, finding the Zero position on the work. Part of the reason has been that the computer keyboard and the machine are about 10 feet apart and my back is to the machine while I am at the keyboard controlling it. This has led to some body contortions and running back and forth about 10 times to tweak the machine into the X0 Y0 position.
The solution, a pendant!
I found this el cheapo USB numeric keypad at Big Lots $6
When setting up the machine its proved hard to tell where the bit center is in relation to the work. There is a shroud around the bit and in some instances a brush. This means lowering the Z axis and then eyeballing from the front and the side, peering under the brush with a flashlight, run back to the keyboard, jog, jog etc…
A while back I found this video posted on Hackaday and realized there was a better way.
I started with a crosshair laser from deal extreme, yes I ordered other stuff too as it was to hard to resist.
Prompted by my friend Michael I decided to take another look at the encoder set up on the OZO machine.
The encoder board, has the spindle signal conditioning circuit mentioned in previous post as well as two SN74LS123 Monostable Multivibrators. Its my guess that these chips act as one shots, conditioning the signals coming from the encoders. On the encoder board pictured below, pin 1 is at the top and 22 is at the bottom. Encoder signals are marked with black connecting lines.
Just found a great resource for open source images. Its called WikiMedia commons. It works like WikiPedia, volunteers post, edit, and manage multimedia content. The media content that then ends up on in the site library is open for any use commercial, private or otherwise.
What this means for me is a source of almost ready made artwork for the CNC machine. Many illustrations are in SVG format, vector instead of raster, and can be easily edited and resized with InkScape.
As a test I started with this original image except I got the SVG version,
