This week:


    Hacked some of my existing boards to try to run Neil's serial code.   Looks like I may have cooked a board or have a loose connection -- the small one doesn't want to program this week.    The working one seemed to be responding.    Will look more when I have a little time.

Boards of the week:

     This week I drew up some more motor control boards...

     The first ones, I was going to use a compatible chip (DRV8811) to the A3977, but it may actually a compatible chip to the A3979, which comes in a much smaller package.   Oops.
The wrong package
     Then I made an adapter board for some older monolithic motor driver chips, so that I had something for the short term.   They will be hooked to the microcontrollers with a ribbon cable, so I can swap back should I build an IC level solution.
     I also relaid out the 8 channel MOSFET board with SMT logic level FETS.   It is shown here, and should drive some unipolar motors.
boards of the week

Flexure Discussion:

    As Neil suggested, I found and talked to a researcher about flexures (doesn't MIT have a researcher for everything).    They work awesome for very fine positioning.    Typically they use a force driven actuator... (i.e. voice coil/electromagnet).    The downside is that the assembly is about 10x the size of the workspace -- i.e. a 1 inch cell would yield a 10 inch assembly.     They sound cool, but I was thinking of stuff on the more macro level (inches of movement).

   He also made interesting comments about how I might make various positioning assemblies (pros/cons of cable v.s. belt v.s. screw, and where to put bearings), and suggested making some air-bearings.    Overall a fun conversation.

Final Project:

The Origional Grand Plan: Automate the world! 

The initial plan was to build a toolkit of hardware/software for building machines.    The idea was, since it was a toolkit, it should lower the bar to building various machines.  

mechanical monster

Here is a sample of the parts I have around that I was thinking could be converted into a pick-and-place machine, cnc router, solder paster dispenser, or all of the above would manufacture a PCB.


Home stretch plan: