Single-speed mountain bikes are a fun and challenging change from normal geared bikes, but the lack of gears is really frustrating on flats. Going uphill is hard as expected, and going downhill you can coast fast, but on the flats you spin your pedals and go nowhere.

I decided to add an internally geared 3-speed hub to my single-speed. I thought I might be able to keep the clean, quiet, and solid feel of the single-speed, but get a bigger gear for the flats.

I started with a 2007 Redline Monocog Flight 29er single-speed. This cost around $800 and was purchased in early 2008.  It came with a 32 tooth chainring and 20 tooth rear cog for a 1.60 gear ratio.  That 32x20 gearing with the 29" wheels is probably similar to 32x22 on a 26" bike.  The photo on the right below shows the original rear wheel.

The hub I chose for this bike is the Shimano Nexus Inter-3 for $125.  This has an overall gear range of 186% and a stated weight of 945 grams (2.1 pounds).  A normal good rear mountain bike hub weighs 300-350 grams, so the Inter-3 adds at least 600 grams (1.3 pounds).  This hub works with disk brakes.

PS12DC Power Switching Board Stock: In Stock Price: $79.00

LabJack just released a new product for power switching applications.  Home project enthusiasts will find this item indispensable due to the flexibility it provides for switching power sources.

For instance, it is possible to control a 5V relay, 4x12V solenoids, and 6x18V fans all with a single board.  One need only provide the separate power supply units, and wire them to the appropriate switching terminals.  Each channel has an LED indicator to easily reference when the switch is on or off.   

The new board is also compatible with non-LabJack products, such as Arduino, homemade boards, PCI DAQ boards, etc.  Simply wire the digital outputs to the PS12DC via the 2x7 pin header.

The PS12DC is designed for medium to low current DC power switching applications.  Controlled through 12 digital outputs, the board can switch power sources ranging from 5 to 28V DC.  Attach the PS12DC to the DB15 connector presented on all compatible devices, and toggle the states of the EIO and CIO digital output lines to turn the switches on/off. 

We are pleased to announce that the LabJack U3 is now supported in FlowStone.

FlowStone is a graphical programming language similar to LabView, but quite simple to use. Developed by DSP Robotics, it has a ready-made module for the U3, and many other devices such as Phidgets, credit card scanners, cameras, and video game console controllers.

The full list of compatible hardware for Flowstone can be found here: http://www.dsprobotics.com/hardware.html

FlowStone is an ideal software package for beginners, and the entry-level version can be downloaded for free from the website. 

The following sections explain how to get started using FlowStone.

Download

Visit the following link for the download: http://www.dsprobotics.com/download.html

You will be asked to create a user account prior to the download.

After creating the account, you will receive a confirmation email for forum access, just click on the activation link.

After the account has been activated, and you have logged in, simply navigate to the forums, and locate FlowStone, then "FlowStone FREE"

File attachment: 

FlowStone LJU3 Example

Need more analog inputs?  The latest LabJack accessory might be for you.  The Mux80 is an analog input expansion board that increases the number of analog inputs on any U6, or UE9 by 80.  Currently priced at $150, this product provides exceptional value when combined with a LabJack device.

Check out the Mux80 product page, or datasheet for more details.

This is a clever design by Paul McIntosh which combines a U3-HV, a tablet PC, and some rotation sensor equipment to measure RPM on a Vespa Scooter.  It is a dyno style project with an onboard DAQ system, and the software layer is based on the Qt framework.  The image on the right shows an embedded widget, which is one of the many features available with Qt. 

The U3-HV is connected to a reed switch and measures the RPM of a lathe, the tablet reports the speed.  Future functionality will include readouts of Km/Hr, Hp etc.  Read more, or download the whole Qt project on the Scooter Computer II project wiki page: http://www.vespalabs.org/Projects/Scooter_Computer_II

Database

It has been a while since the last update on the automated bartender, but the project is still underway.  The latest additions are a database and a new design of bottle stopper.  

Basically, the database runs on the computer connected to the Labjack, and contains a list of what ingredients are needed for each drink.  If some ingredients are missing, the program suggests a backup, i.e. coke for pepsi.  Simply modify a table in the DB to notify the program which bottles are currently connected to the bartender.  The program searches the database for drinks that can be made with the connected ingredients, and then lists the possible choices on the interface.

There is also a mobile version of the interface so anyone with a wifi enabled phone can get on the network and pour a drink.  The next goal is an android app with voice recognition, so saying "Pint of Jack and Coke" would pour the drink.  Since Android has a built in speech-to-text engine the process shouldn't be too difficult.

Updated stopper design

LJLogUD V1.07 has been posted.  Go to the LJLogUD support page.

LJStreamUD V1.11 has been posted.  Go to the LJStreamUD support page.

Real time machine control with UE9 and VB.Net

The lab spinner and laptop interface

Inside the control box, UE9 on the left bottom, and a proprietary module attachment for peripheral interface on the right bottom.

This is a laboratory spinning machine.  One each working in Texas, South Carolina, and Switzerland.  3 servo axes drafting system, 1 linear axis ring rail, 2 inverters for spindles and suction.  All of it running through VB.net in Windows 7, real time.  

Developed by Prof. Dr. Urs Meyer, Switzerland http://www.texma.ch/

UE9 Inside Burj Khalifa

The pinnacle of the Burj Khalifa Image property of: thepropertycompany.ae

Two enclosures used to house the UE9 at different measurement locations.

At the top of the tallest building in the world, a UE9 is gathering data on how the structure moves, vibrates and tilts.  The data provides insight into how the building reacts to forces in its environment.  We asked Tom Lawton, Senior Systems Engineer at CPP Wind Engineering & Air Quality Consultants, about the UE9 in this study: