PCB Milling With A Makerbot

May 21, 2011 by Caleb Kraft 15 Comments

[Keith] wanted to use his makerbot for some PCB milling, but he ran into a pretty big problem. The platform that his PCB would sit on was mounted with a layer of double sided foam tape and was not perfectly aligned to the head. Not only that, but it would tilt when pressure was applied. This made the result of the milling completely unacceptable. To remedy this, he made a new platform that is not only rigid, but he has made it so that there is the ability to adjust it for perfect alignment via adjustment screws in the 4 corners. At the beginning of each session, he can be absolutely sure that everything is aligned perfectly and his PCBs show a huge improvement. You can see a comparison of the two in the following picture.

[via HackedGadgets]

Arduino I2C Sniffer

May 21, 2011 by Caleb Kraft 11 Comments

[Johngineer] found himself in need of an I2C sniffer, but didn’t have one available. Necessity is the mother of invention, so he put together this I2C sniffer sketch for Arduino. The arduino will record what is going on for a set time interval, then dump the data via serial as a .csv. You then have to plot it to see what is going on. [Johngineer] recommends Livegraph, since it is portable and easy. As you can see in the code, the time interval is adjustable, but you have the physical limitations of the RAM on the board to consider. This seems like a pretty handy piece of code stored around, effectively giving you a passable I2C sniffer in a pinch.

DIY Spectrophotometer

May 20, 2011 by Kevin Dady 26 Comments

[Charlie] has been making a DIY Spectrophotometer, and while it is a “shambling mess of information-age technology!” it is still much better than ours. Focused around an arduino, bits of lego, and a flashlight, this creative device rotates a diffraction grating (flake of compact disc) aimed at a photo resistor. As the light spectrum is passed over the sample, the photo resistor measures how much light is reflected and that data is passed back to a pc.

As nothing is as ever easy as it should be, a big problem popped up with using a servo. It was way too course, meaning the entire spectrum would be jumped over in 6 steps. A quick robbery of a gear assembly from a floppy disk drive and the motor movement was smoothed out. A little too well because 120 degrees of the servo is not quite enough to cover the entire spectrum. Oh well there is always room for improvement.

1Hz Timebase

May 19, 2011 by Caleb Kraft 16 Comments

Check out this nice simple method of achieving a 1Hz timebase. This is basically a lesson in dividing crystal frequencies in circuits to get the desired result. In this case, they are starting with a 32.768KHz crystal and dividing it down. Instead of using an NE555 like many projects, he chose to go a direction that would yield results less prone to drifting with temperature variation. The method chosen was a CD4060 frequency divider, basically just a chain of flipflops. The divider is one step short of getting to the desired result so an additional flipflop has to be added. This is pretty basic stuff, but a great read. They go into detail as to how it all works and why you would use this method.

Pssst, hey, remember that time I told you to just use a 1Hz crystal? yeah, we can laugh at that again.

[via HackedGadgets]

Open Source Linear Bearing System

May 10, 2011 by Mike Nathan 53 Comments

makerslide

While we normally don’t make it a habit to feature Kickstarter projects, we couldn’t pass this one up. [Barton Dring] from BuildLog.net is putting together a project called MakerSlide that we’re sure will interest many of you out there.

Through his various CNC builds, he has found that one of the more expensive and frustrating components to obtain is a linear bearing system. He notes that commercial systems are expensive, and while an occasional eBay bargain can be found, it’s not the ideal way of going about things. He also points out that homebrew systems usually work after some tuning and adjustments, but can be time consuming to build.

He is proposing a v-groove bearing system, complete with wheels made from Delrin, as a standardized replacement for all of the aforementioned solutions. He anticipates selling the rails for about 10 cents per centimeter, putting the average cost of a 4 foot system around $20.

As a bonus, he is offering up free MakerSlide materials to anyone that sends him a “new, innovative or interesting open source design or basic idea that uses the material.” You would only have to pay shipping in order to get your new project off the ground.

Standardization is always good, and seeing this rail system go into production would definitely benefit the hacker community. Take a minute to check it out if you are so inclined.

Building Your Own Router Lift-out Mechanism

May 3, 2011 by Mike Szczys 11 Comments

Adjusting the bit height on a router table can be a pain in the butt. Traditionally you needed to get into the cavity under the table top in order to make these adjustments, and it’s hard to make the adjustment and measure the height at the same time. Modern routers now offer the option to adjust height through a hole in the plate that sits in the router table, but this is usually only found on the more expensive models. Rather than buy a new tool [Urant] built his own router lift.

He’s using recycled closet rails to give his rig some smooth operation. These are the rails and runners that let closet doors hang from the top jamb. He saved them when replacing the closet doors in one of his rooms. There’s a triangular gantry which hosts the router, allowing it to move vertically on the three sets of rails. The threaded rod in the foreground of the picture above lets the woodworker adjust bit height by turning the nut at the top. Once mounted in the router table the nut is accessible through a small hole in the table surface.

Isolation Transformer 101

May 2, 2011 by Kevin Dady 23 Comments

[Todd Harrison] has released a ~50 minute video covering everything you want to know about Isolation Transformers for protecting yourself and your costly equipment. Admittedly I have not given the subject much thought, but if you need to measure high voltages you should probably watch this video.

[Todd] Explains the differences between different types of transformers, including cost, why you would want one, safety and plenty of theory. Whiteboard in hand, all the details are clearly explained. If that’s not enough to convince you, there are some fun “don’t try this at home” experiments that hit the point home.

He has a pretty beefy 8 amp 40 lb monster that cost a fairly large amount, though its worth it to be safe. Unless you think you’re going to need that type of amperage, you wold probably be fine with a smaller model. The product shown in the video is a hospital grade, and requires a mod to make it safe for your bench. [Todd] explains that mod as well. Even if your not planning to do this, its still cool to see a transformer bigger than your hand. Plus it makes a pretty cool sound.

Join us after the break for the video.

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