LapRap is a multi-goal project to bring high-resolution three-dimensional printing within the range of the home hobbyist and deliver it at a price comparable or lower than other hobbyist designs.  Objects printed on a LapRap-design printer should be sturdy enough to use in the creation of molds and lightly machinable.  The LapRap project has multiple goals:  design a control system for converting a off-the-shelf inkjet printer to 3D printing by controlling the paper-feed mechanism, determine optimal recipes for both a inkjet-printable binder and powder to be printed into, design a good generic framework that will support most printer components and properly hold powder both in the printing area and in reservoir, and produce easy-to-use programs for conversion of 3d models in STL format to printable "slices".

The main reason that this is a community-oriented project and not a personal one is simple.  I, the originator, am most emphatically not a coder, hardware hacker, chemist, or anything else.  I just want to be able to make anything, at any time, at high resolution.  If I were well-off, I could just hire someone to do the design work for me, but I'm not even that.  I am a packrat, though.  I have laptops.  Lots and lots of laptops.  None of them are in great shape, none of them are new, but they would make great print servers for your own 3d printer, and  they're taking up space on my shelves.  So, here is the plan.  I am going to set the official goals for this little project, determine the goalposts, and frame the design.  You, oh coders and hackers and chemists, will be working out the details.  When we decide that a goal has been reached, one of the laptops will be shipped to the person that we think did most of the work to get us there.  If they don't want it, they can specify what gets done with it.  I will dig up a local charity that could use a laptop and hand it over to them in the name of the "winner".

"Winner" was in quotes there because it's funny.  If we complete this project, the world will have a high resolution build-at-home 3d printer that will cost a fragment of a commercial model.  "Winner" won't begin to describe the situation we will be in. 

To begin with, efforts will probably focus on taking any of several older HP printers and converting them.  When the conversion is complete, the printer will appear unchanged to the hosting computer, but its paper-feed mechanism will have been removed and been heavily modified.  Currently, the plan is to attach a "parasitic" control system that will monitor the encoder wheel used to keep track of the paper roller and use that information to move the entire print-arm over a flat bed.  The parasitic controller will be based on the Arduino development board along with the Motor Control Shield developed by adafruit industries.  These pieces of hardware were chosen for their cheapness, availability, and ease of development.   The Arduino system will also control  the system for adding powder media to a descending print tray.  Optimally, there will be sketches for determining the proper amounts to drive the various motors that are brand and part independent, allowing for a lot of different printers to be convertible by a relative novice with minimal soldering and carpentry skills.