Archive for the ‘CNC’ Category
Stepper motors are great for accurate positioning because they move in discrete steps – a feature that makes them very appropriate for CNC software control. But every once in a while you have an application where you need to press a button and rotate some kind of a jig at a preset angle or move something a preset distance if it’s a stepper-driven linear stage. So, I decided to modify an earlier Arduino sketch I wrote for testing the world’s smallest stepper motor to make it a bit more useful (and clean any bugs in the process). Keep reading to see what came out … Read the rest of this entry »
This project came about as a result of my propensity to never throw away parts that were designed to or can be adapted to move electrons. I am also very interested in mechatronics and motor control in general and so it was all but certain that over time I would have accumulated enough of various discarded data storage devices because they are so cleverly combining parts of both mechanics and electronics. We live in world filled with discarded devices that only a few years ago were the stuff of science fiction. I always feel bad about the discarded yesterday’s technology and it gives me an extra kick to have it re-purposed for today’s needs. Read the rest of this entry »
Here is another model I’ve designed around the size limitations of Groover’s micro laser cutter from discarded DVD drives – 1.5″x1.5″. I wanted this model to be in the same scale as my earlier Supermarine Spitfire model – 1:212 scale after seeing a 1944 photo in Famous Aircraft: The P-38 Lightning (by Gene Gurney) picturing a P-38 (F-5 version on a reconnaissance mission) accompanied by a Spitfire and the caption said: “Two of the fastest aircrafts in the world at the time this photo was taken”. I though it would be nice to see them together again, materialized on a much smaller scale Read the rest of this entry »
While I’m getting ready to rip open some 10+ broken DVD-RW drives coming to me from an eBay seller, I though it would be great to have a testbed for the bipolar stepper motors I will harvest from those.
I have a bunch of ULN2803AG Eight Darlington Transistor Arrays with Common Emitters left from past projects and these can sink (but unfortunately not source) peak loads of 600mA (500mA continuous) and are well suited for power application like driving small motors. However, there is a problem with 4-wire bipolar stepper motors: they don’t have the common points of windings wired to the outside which would be needed for providing the motors with power. See the ULN2003 datasheet for more information about the IC: ULN2801,2802,2803,2804 and 2805 Darlington Array datasheet
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The idea for this model came to me when I was browsing Instructables and came upon this nice project – the Pocket Laser Engraver. Basically, its author, Groover, describes building a laser diode cutter not unlike the one I’m using here but based on parts of discarded DVD-RW drives. In fact, the diode he’s using is also salvaged from one of those drives. I got intrigued by the project due to the fact that I never throw anything electronics away and I have a little stash of CD and DVD drives myself that I would love to put to some fun use.
I should have said “laser diode cutting” but did not want to spoil a great looking title I had this CNC setup for about a year now and and have been tinkering with different setups for the laser diode but only recently have made any progress.
Please make a note that if you are going to do this yourself, you owe it to yourself to buy a pair of nice ($35 or so) color filter safety glasses designed for the particular wavelength of the laser you are going to use. Mine is 650nm – red. I specifically wanted a laser in the visible part of the spectrum – if it’s going to burn my eye I want to at least know about it and give my reflexes a fighting chance to blink and shield my eye(s) from more damage. An infrared might have been more efficient and less picky about colors (with red laser forget about cutting any light colored material) but it requires more safety discipline.
The CNC machine it’s based on is Sable-2015 which I bought in the Summer of 2009 from eBay seller Luke-Chen in China. I have also bought the controller and the 24V DC power supply from Luke-Chen and had it running within hours after the package came in the mail. Read the rest of this entry »