Ever since mechanical design tools went 3D, one task seems to have stumped the software designers. The melding of 2D graphics into a 3D design just doesn’t seem to work as smoothly as it should. At least that’s been my experience with ProEngineer and SolidWorks. Mechanical designs often include graphical overlays/labels and silkscreening. Free-hand graphics are very difficult to deal with because they have to be regenerated in a vector format. Some tools allow a bitmap image to be imported and then the designer has to trace it to approximate the design using standard lines, arcs, splines, etc.
Most design tools have done a decent job when it comes to text. They allow text to be placed on surfaces which can then be extruded as protrusions or cuts into a part. In order to recreate a company logo, it is often necessary to use a specific font, but the CAD packages usually have a limited number of fonts available. Identifying a font can be a challenge sometimes. This was the case just recently so I turned to a useful online tool: Identifont.com
Identifont, in the spirit of the game ’20 Questions’, allows you to answer several questions about the characteristics of a text sample in order to narrow down the possible font matches (listed to the left of the page). Give it a try and see if you can determine the font used in the image below.
In light of the invasive behavior of Google these days, I am encouraged by a search tool recently discovered. Actually, I had them bookmarked for some time under the name “Clusty”. Now they’ve rebranded as “Yippy”. Yippy claims to respect your privacy on the internet by not storing any of your search history and not sharing any of your personal data. They also offer a family-friendly search. Yes, this means they filter sites. They have established themselves in several libraries and other public surfing locations. Learn more here and give them a try.
I’ve done a little genealogy research and found that my Great-Great-Great-Grandfather was a blacksmith. I wonder what he’d think if he saw these videos…
Source: Hebo | Stratford Gate Systems | Gizmodo
Here is a ‘got to have’ security/anti-theft program for any mobile computing device. The Prey Project is an open-source program so you can always have one of your computer geek friends look it over to make sure nothing nefarious is going on.
The concept is pretty simple. You place a file somewhere on the web that can be deleted by yourself. The program is setup to run on a schedule and it simply pings the file. If the file exists, the program goes back to sleep until the next scheduled execution. However, if your device goes missing, just go delete that file from the web and watch Prey Project go to work. When it can’t locate that file, it captures data from the device including a screen capture, webcam snapshot, and network information. It then forwards all this information to the email you have setup. A sample of the email is below.
Good news my friend, it seems we found it.
Here's the report from your computer:
########################################################
# geo
########################################################
:: lat=##.#######
:: lng=-##.#######
:: accuracy=##.#
########################################################
# network
########################################################
:: public ip=##.###.###.###
:: internal ip=###
:: gateway ip=###.###.#.#
:: mac address=##-##-##-##-##-##
########################################################
# session
########################################################
:: logged user=ZZZZ
:: uptime=\ZZZZ-PC has been up for: 0 day(s), 16 hour(s), 53 minute(s), 22 second(s)
Happy hunting!
--
Your humble servant, Prey
http://preyproject.com
An image named prey-screenshot.jpg is attached to this message. A thumbnail is below.
An image named prey-picture.jpg is attached to this message. A thumbnail is below.
It was pretty impressive to punch in the latitude/longitude coordinates into Google Map and it pulled up a streetview photo of my house. I tested by driving to a local hotspot and the coordinates pulled up a streetview of the CareNow facility I was sitting in front of. Kind of spooky, but almost makes me want my laptop to get stolen, just so I can catch the perp… :o)
Source: Prey Project
For a long time now I’ve had an idealistic view of Montana. I’ve always felt like that would be the place to go to get away from the nonsense of this rat race. I think it’s the allure of the wide open range that caused me to fall in love with Montana back when I was a child. Maybe I watched too many westerns or Marlboro Man commercials. Who knows.
Well, so much for that image. This is a few months old but I just ran across it. It appears an aluminum bat manufacturer has been sued and the plaintiff was awarded $850,000, upheld by the Montana Supreme Court, because they failed to properly warn of the increased speed at which the ball would leave the bat relative to a traditional wooden bat. Apparently this increased speed results in a decreased time of travel to the pitcher’s mound. Though it is unfortunate a man was killed by a hit ball, I seriously doubt he would have been able to read a warning label on the bat from that far away.
I really thought Montana folks would have their heads screwed on tigher than that.
Source: Insurance Journal
Thermal expansion is a pretty easy concept to grasp. You heat up a steel disk and its diameter increases as well as it gets thicker. But a point of confusion arises when a hole is added in the center of the disk converting it to a ring. Does the hole get larger or smaller when the ring is heated?
A line of thinking says the hole will get smaller because the material will expand into that void. It’s easy to rationalize this, however it is incorrect. Here’s an attempt at a mathmatical proof. Please go easy on me and my assumptions/simplifications.
Without going into calculus, consider a ring cut up into 360 x 1degree segments. Now look at an individual cell along the neutral axis which has initial radius R0. For small angles let’s assume this cell is a square.
The circumference of this neutral axis is C0 = 2*pi*R0 but we can also represent it as C0 = 360*A0 because A0 is 1/360th of the circumference. Thus,
C0 = 360*A0 = 2*pi*R0
A0 = R0*2*pi/360 [solve for A0]
The initial ID0 can be calculated in terms of A0 which is the arc length and the radial width of the cell.
ID0 = 2*(R0-A0/2)
ID0 = 2*(R0 – (R0*2*pi/360)/2) [sub in for A0 from earlier equation]
ID0 = 2*R0*(1 – pi/360) [factor out R0]
ID0 = 2*R0*(360-pi)/360 [common denominator]
Now consider this cell is heated and expands in all directions. For this example, A1 = A0 *E where E is the expansion multiplier. Using the same equations as before…
C1 = 360*A1 = 2*pi*R1
R1 = 360*A1/(2*pi) [solve for R1]
ID1 = 2*(R1-A1/2)
ID1 = 2*(360*A1/(2*pi) – A1/2) [sub in for R1]
ID1 = 2*A1*(360/(2*pi) – 1/2) [factor out A1]
ID1 = 2*A1*(360-pi)/(2*pi) [common denominator]
ID1 = 2*A0*E*(360-pi)/(2*pi) [sub in for A1]
ID1 = 2*R0*E*(2*pi)/360*(360-pi)/(2*pi) [sub in for A0]
ID1 = 2*R0*E*(360-pi)/360 [cancel (2*pi)]
Now assume you chopped the ring into an infinite number of segments. The equations now become:
ID0 = 2*R0*(infinity-pi)/infinity
ID1 = 2*R0*E*(infinity-pi)/infinity
(infinity-pi)/infinity is equal to infinity/infinity which equals 1 so the equations now reduce to
ID0 = 2*R0
ID1 = 2*R0*E
This makes perfect since because as the cell size gets smaller, 2*R0 is a very good estimation of the ID.
Now the big question … which is bigger – ID0 or ID1? Take a look at these two equations and you’ll see that ID1 is larger than ID0 by a factor of E. Surprise!
Along with Sugru, here’s another great prototyping compound. It doesn’t have a creative name like Sugru, but it looks like a very promising material.
Source: Inventables
If you’ve ever forgotten your BIOS password or picked up a 2nd hand computer and found that a BIOS password was set, you know how useful the following info might be.
Break Through the BIOS Password
Courtesy of Cryptome
If you have ever had an intermittent laptop power cord and had to cut away the strain relief molded around the connector in order to re-solder the connection, then Sugru appears to be for you. I am anxious to get some of this compound and try it out. I currently have two cords with electrical tape wrapped around the connectors. And unfortunately the tape does not provide sufficient strain relief so I frequently have to re-repair the connections. Sugru is a moldable silicone compound that cures quickly. There are many other applications for Sugru, so be sure to check out their website and some of their YouTube videos to get your creative juices flowing.
Credits: LifeHacker.com
Years ago, I was involved in a redesign project for some central office cabinets. The equipment at that time was housed in refrigerator sized enclosures that lined up and would fill an area the size of a small home. Today you could probably replace this equipment with a product the size of your home PC, but that’s another story.
The redesign effort was initiated due to increased concerns over EMI. Processor speeds were increasing and the risk of radiated emissions causing interference with nearby radios (fire stations, police, etc) was becoming a real issue. Today’s designer addresses EMI at the component and PCB level to minimize the macro effects. But at the time of this effort our product was mature and total redesign was not in the plans, so we chose the Faraday cage approach. The goal was to wrap the cabinet and contain the EMI.
My task was to address the cable entry and exit points so I’m going to pass the buck on the following design oversight (even though I probably would have overlooked it myself). Another engineer was addressing the front door redesign. The original cabinets had plexiglass doors, but the new design approach was to convert to an attractive molded plastic appearance and integrate a metal insert to provide structure and address the EMI issues. Pretty straight forward, right?
Everything went smoothly thru the prototyping. The hinges, gaskets, latches, injection molding, and sheetmetal all came together to produce a significantly better looking product. The seal to the cabinet looked good as well. Now all we had to do was perform some EMI tests. This was going to be easy because we had an in-house outdoor test site. We took the cabinets out, everything got cabled up, powered up, checked out, and ready to start the test the following morning. Then came the surprise.
It was early April, so we were not totally finished with winter. Overnight a cold front blew in and temperatures dipped into the 40F’s. When we arrived to work to begin the tests, we were shocked to find that these beautiful new doors now looked like Pringles potato chips! The latch and hinges constrained things a little, but the top and bottom of the 6-1/2 foot tall doors were pulled away from the cabinet by about 4″.
Then it became apparent what had happened. The thermal contraction of the plastic was significantly higher than the contraction of the sheetmetal. At 40F we measured a gap of about 4″. As the day warmed up, the gap became smaller. Add a scale and we just designed ourselves a very large thermometer! (The solution was to add slots and shoulder washers to the attachment points between the sheetmetal and the plastic to allow them to expand and conctract independent of one another.)
Next week I’ll discuss how to design a clock using only a cell tower and the sun…