At I Heart Robotics we are a little obsessed with ROS. We have been using it regularly for several projects and to make our lives easier we built this little tool.
Rind is an indicator applet for ROS that runs on Ubuntu and possibly other *nixes. It provides a means of starting and stopping roscore, launching rxconsole and listing the available topics and running nodes.
The CityFlyer ground station takes different approach to developing a control system for UAVs. While other systems try to provide as much information as possible, this one seems to focus on readability. Also, since it is based on GTK+ and ROS it may be useful for other robots.
It uses the osm-gps-map widget to display maps from Open Street Maps. This might be more useful than google maps if you wanted to setup your own map server that uses maps generated from your UAV. The GPS map viewer is also available separately as a standalone tool for ROS.
Each of the instruments are well documented and implemented using the Cairo scalable vector graphics library, which means that each gauge could scale up to full screen without looking pixelated. Controls are also provided for a high contrast mode which might be useful for daylight readable displays. Since the individual instruments are implemented as GTK widgets they could also be used to build your own ground station.
Rumor has it that the lead developer is graduating soon and looking for work, so feel free to contact him here.
This looks like the beginnings of a nice NXT based delta robot.
This fine delta robot was built by Viacheslav Slavinsky. He has extensive information about the robot here, including some of the math for the kinematics. Thought he doesn't provide the full differential equations of motion, a simplified model is probably sufficient to get started.
While this isn't a delta robot, it is a parallel manipulator and awesome. The increased workspace is a nice touch.
This one reminds me of marionettes.
Maybe I'll have some delta robot packed biscotti for breakfast.
It looks like the Pixhawk team has made some more improvements to their ground control software. Most importantly some progress is being made towards interoperability so that various aircraft can use the ground control. MAVLink provides a telemetry interface that can be implemented on a microcontroller to enable autopilots and IMUs to connect to the ground control.
The documentation for the project is looking pretty good, which is how I found out that the software supports exporting data to MATLAB.
It make me really happy that the PR2s are going on sale, and while I probably can't personally afford one yet, I can imagine being able to buy a used PR2 in 10-20 years. Maybe I should wait for the PR3 in 15-25 years.
Even with adjustments still being made the performance of EggTorte is quite impressive, and we look forward to seeing more of EggTorte in the future.
Previously he posted schematics of EggTorte here and there is a lot that can be learned just from looking at his excellent work.
Here is a video of how to cut screws using a screw cutting tool. After cutting the screws a quick pass with a file will help remove any remaining burrs. Make sure to avoid cross threading cut screws as they will quickly destroy the threaded hole.
Another option if you are cutting larger or longer bolts is to thread a nut onto the bolt then use a hacksaw or Dremel tool to cut it to length. When you remove the nut it will straighten the thread and remove the burrs at the lend. If you are cutting threaded rod use three nuts, jam two of the nuts together to provide a place to clamp the rod then thread the third nut on a cut it like a bolt.
Screw cutting can be useful because it is often cheaper to buy a box of 100 screws and cut them down to size, rather than buying a few of each length for those times when you need a screw that is just the right length.
These bolts were tightened by hand and failed at an unreasonably low torque. I suspect that this was due to cost cutting on the part of the bolt manufacturer.
It appears that they can save about 8% on the cost of fastener production by not heat treating the bolts. This would enable the bolt vendor to under bid the competition by selling bolts below the cost of making properly heat treated bolts while still making a profit.
This is the second time I have seen bad bolts in recent years, and I hope that manufacturers are testing the strength of bolts they order when they are used in critical applications where failure could mean injury or death.
This site also has some additional information about bolt failures.