Gawlowski Design

I think every Mechanical Engineer I’ve ever talked to would love to have their own CNC milling machine. Unfortunately, their size and expense keeps them out of most cubicle farms. To the delight of all, the sophistication of compact, table top mills is increasing while their prices drop. One of the latest is the Roland MDX-540 SRP pictured here, starting around $19k with a maximum build size of almost 20×16x6″. Desktop Engineering magazine has an in-depth review of this unit, and comes away very impressed. Now, how do I justify buying one…?

Anyone who has performed an extensive patent search knows what an arduous task it can be, even with the search features at the Patent and Trademark Office’s website. Well, finally, Google has applied their search technology to the task, in the form of a beta version patent search! You can try it out here. I found it to be worthy of the ‘beta’ moniker - it works well, but some features are still lacking. For example, the ‘read this patent’ buttons weren’t working for me, but if I click on one of the images, I can navigate through the patent pages that way.

I imagine the rivet shown here looks very familiar to most mechanical engineers - at first glance, it looks like a typical metal pop rivet. Upon closer inspection though, you’ll notice the wide head and slotted body; this is an all-plastic expansion rivet designed to be used in similar manners as a pop rivet. It’s a good choice when working with softer materials or where a high clamping force is not needed. I’ve seen flat metal washers used on the back side of riveted joints to help protect the parts from the rivet’s clamping force; a rivet like this would have been a much better choice in that case. They’re made by Fastex.

Ever wondered how your Christmas lights stay lit when a bulb goes out, even though they’re all wired in series? EDN has the answers in a nicely technical article here.

Most of you have probably thought about building (or have already done so) a system to automatically water your Christmas tree. Mark McCuller designed a nice system that uses water level sensors to maintain a precise water level at all times. Click here for the extremely detailed plans in PDF format.

Lastly, click here for some good instructions on how to build an electronic circuit that sequentially cycles power strings of Christmas lights (turning on and off entire strings at one time, not bulb-by–bulb control).