In The Shop: Great Innovations Ultimate Engineering Screw Chart

I was reading the following article about the Engineering Slide Charts and realized that it was now available as an App for my phone.

Engineering Slide Chart in Play


The slide rule may be a quaint anachronism in this age of ubiquitous computing, but there’s still a place for the slide chart, the volvelle, the nomogram, and other hand-held “paper computers.” These are still published by a few companies, and are a handy source of on-the-spot reference data, particularly in field or workshop environments that may be inhospitable to or inconvenient for electronic devices or books. Slide charts containing key screw, bolt, and nut data have been around for decades, and the folks at Great Innovations identify TAD’s Universal Reference Calculator, discontinued in the mid 1990s, as inspiration for their chart.

The thing itself is simple enough: a clear plastic outer sleeve printed with dimensional drawings and callout fields on both sides, and an opaque plastic inner card printed with the callout data. Sliding the card back and forth in the sleeve indexes all the callout data simultaneously, and of course can be used bidirectionally—you can get key dimensional data from a known fastener size, or figure out fastener size from some real measured dimension. Overall, the chart is about 1/16? thick, flexible, and measures 8.75? × 11?—about the same size as a standard sheet of printer paper.


The front includes sliding tap, drill and stress area callouts for SAE and metric screws, in both standard and coarse threads, as well as key dimensions—such as countersink depth, counterbore depth, socket cap size, etc.—for various types of screw heads, points and nuts. Detail boxes cover metric and SAE shoulder bolt dimensions. The areas not occupied by the sliding chart fields are filled up with static tabulated data—metric/SAE drill equivalent diameters, fractional/decimal drill diameters, common unit conversions, metric prefixes, and SAE bolt grade markings.


The back has sliding indices for sheet metal and wire gages, dimensioned thicknesses, densities, and minimum bend radii; critical dimensions for tapered pipe threads both NPT and BSPT; and a hardness converter for Shore durometers A-OO with typical reference materials (e.g. “Shopping Cart Wheel”) and conversion factors for Brinell and Rockwell A-C hardnesses, as well as approximate tensile strengths. Static tabulated references include the numbering system for carbon and alloy steels, a circular actual-to-nominal pipe size gauge, and a slew of handy equations from statics, dynamics, electrical engineering, and statistics. One of the long edges is printed with an English ruler, and the other with a metric rule. No space is wasted; pulling out the sliding inner card reveals three more handy tables printed in the “dead spaces” between the keyholes—densities of common metals, a key to common mechanical drafting symbols, and a key to AWS standard weld symbols.

I use the chart in my workshop quite often—mostly, so far, to look up tap drill sizes and gauge nominal pipe diameters. It’s compact and durable and water- and grease-proof, and has saved me a lot of time running back and forth between my web-connected smartphone, tablet, laptop, or whatever (all of which I like to keep clean) and my dirty workshop and tools. Mine is a review unit I got for free, and I would recommend it enthusiastically to others if not for the price of $24.99, which is about $10 more than I think I would pay for the thing. A functionally-equivalent app is available for both iOS and Android for $5 less, but in my mind that sort of defeats the purpose, which is that you can keep the chart on-hand in an environment that might not be hospitable for a handheld electronic device, and don’t have to worry about keeping it clean, charged, or safe from damage.

Engineering Slide Charts


Replacing a Cracked iPhone 3G Screen

crackedI recently obtained this wonderful iPhone 3G.  Well it will be when I Install a New iPhone 3G Display.  Then I will determine if I want to equip it as a pay as you go phone or just leave it as a nice iTouch or Strava tool for my bike.


DIY Doorbell Will Send Pictures Of Your Guests To Your Droid.


I found this project on TechCrunch written up by John Biggs.  Read the entire article on his website for all the related comments, articles and fun stuff.  I am simply saving it here to copy it to a maker I know with an Arduino.

Say you’re a misanthrope and you’re afraid of humans. What to do? Well, you could cower in the dark when people ring your doorbell or you could laugh derisively at their smug faces in the screen of your iPhone. I’m going for the derisive laughter.

This DIY Arduino project involves a simple circuit, a webcam, and a few API calls to PushingBox to enable a truly enjoyable derisive experience.

The system works by pushing images grabbed by the webcam through PushingBox to an app like Prowl or When the doorbell is pressed, it sends a serial signal to the Arduino board which in turn notifies the various services. The webcam picture then gets sent over to you so you can decide whether to let whoever is outside in.

It’s probably a little more complex than it needs to be, but if you’re totally into watching the world pass you by it’s a great solution and a fun weekend project.

Project Page


How I am Building a Low Effort Home Surveillance System With My PC

I reviewed and installed Active WebCam.  Active WebCam would not communicate with my FTP server which is setup for sftp and is primarily a trial version of a purchased package despite all the labeling.  So it was out.

I moved to the much simpler Secure Cam which I like a great deal better. Secure Cam worked well with Motion sensors but was not easy to have the pictures sent and did tend to fill up my local hard disk even during the test.  Nothing that was going to provide a problem; however, it wasn’t easy to see how to keep the directory clean.

But the third bed was just right.


“Yawcam is a shortening for Yet Another WebCAM software, and that’s exactly what it is ;-). More precise Yawcam is a webcam software for windows written in java. The main ideas for Yawcam are to keep it simple and easy to use but to include all the usual features.”

I liked if from the description, and the Title: a nod to Yahoo! and earlier programs. It has a simple interface window (shown at right) and great documentation.

md_actions_emailIn addition to all of the usual features, and it appears to have the complete set, it has a excellent interface and monitoring setup for the motion sensor.  The motion sensor also allows you to run an executable and I would like to hack my house someday and have it turn on lights and an alarm (that will be a later project, aren’t they all); however, it is the only one that allows you to configure GMail SMTP server and email anyone with the pictures so that if the machine is taken, I will still have the images. 

This is a great tool and I am looking forward to using it for a variety of reasons, if nothing else, I at least get to use it to monitor my non-existent cat.


Ask an Engineer

From adafruit comes “Ask An Engineer” on Vimeo.  Sign up and watch, read the Adafruit blog, get online and ASK!

See all the videos.


DorkbotPDX: People Doing Strange Things with Electricity.



The company name Rapportive says it all, build rapport with the people you GMail.  I am using the Rapportive Chrome Extension and it pulls up the recent tweets and other information from users you receive and send emails to.  This tool is working out well to increase the professionalism of my Customer Relationship Management.