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Express-Bot: A Simple Modular Robot for the 9797 Set

I frequently hear from teachers and other users who have only the LEGO Education NXT Base Set (9797), looking for building instructions and an alternative to the standard Robot Educator Model (REM) design that is included in the LEGO Education software. Many are looking for a base robot design that is quick and easy to build but flexible enough to use in a variety of lessons and other activities. As an educator myself, I often have a need for such as design as well. So I recently developed and posted a design to try to fill this need.

The Express-Bot is a simple robot vehicle with several modular attachments that can be individually built, selected, and combined, and everything can be built using a single 9797 set (I also resisted using the "Hassenpins" that were added to the new 9797 set, so that everything can still be built using only the original 9797 set, which lacked these). Designs for several simple attachments are included, using all of the standard sensors and the 3rd motor in several ways. Here is a page of ideas showing some of the many ways to combine and use the attachments. Of course it would be easy for users to customize or design their own attachments as well.

Three Ways to Build
Teachers know that it is important to try to keep all students challenged (and thus interested), while still providing help as necessary. For some students, building a model from step-by-step instructions is "too easy", but there are usually other students that will need them. Most students are somewhere in between. In addition, teachers have practical concerns such as often needing print-friendly building instructions, but with a desire to save paper and ink as well.

To try to address these needs, for Express-Bot, I have formatted the building instructions in a new way. For each module, there is a one page view of the completed module. Experienced builders can challenge themselves to build the modules using only these views (by "reverse engineering" them). Then for each module there is an additional one page of "building hints" (partially disassembled views). Most users will be able to build the modules using just the hints plus the completed views (which together is only one double-sided sheet per module). Finally, for the driving base, step-by-step instructions on 6 pages are also provided for print or online use. All instructions are provided in PDF form for compact and easy printing if necessary (can be used online as well), and a PowerPoint format is also provided to allow teachers to easily create their own custom handouts by selecting only the pages they need and editing as desired. Permission is given to print and redistribute freely.

Some Design Goals
In addition to the new approach on building instructions, Express-Bot has a number of other design goals, many of which are practical concerns that teachers and others may appreciate, such as:
  • Fast to build (under 15 minutes for the driving base)
  • Compact and sturdy, slips easily into a backpack or purse
  • Choice of fixed skid wheel or castor wheel
  • Screen faces user at send-off
  • Battery, charge port, and USB all easy to get to
I don't have programming instructions specifically for Express-Bot posted (it is designed to be used in a large variety of ways, and I encourage users to make their own programs). However, for those wanting to see some example programs, many of the programs designed for the Multi-Bot project and available on CD will work with some or no modification for Express-Bot, or at least provide a starting point for learning.

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