MTM
                  -
For the group project we decided to finish one of the unfinished machines from the last years here in Fablab BCN, we chose the
    MTM machine
the aim is to recycle/reuse most of the lab products to avoid ordering new components with no need.

First idea was to change the bed mechanical system from lead screw mechanism to belt movement because we don’t have enough screws while
 the belt we can cast it or cut it here at the lab.

   

           Fabrication part

                    -First we thought about the best belt mechanism to use in parallel there were others thinking about the material and the gears dimensions
 and movement,
This plastic is hard enough to overcome tension and flexible enough to bend around the gears, belt calculation & gear
 

                            
                                 

 

          

           Software part


               -JOSE PABLO wrote: A review was done on the grbl code that will be loaded in the microcontroller that will control the machine. In the github website of David
 Mellis' revision of the grbl code, we find the different C codes. In the settings.h file
several constants are defined, that will
 need to be reviewed once the machine is assembled. We don’t know yet if we will be having the same revolutions per inch or the same federate, so that remains to be
 seen in the near future.


                -A nice website was found, explaining the basics of grbl. It also shows a way to change the constants mentioned before, through the serial terminal, but we’re
 not sure if that can be done with the David Mellis’ version of grbl, which is interfaced with the PC through a processing program.


Another important code to look at are the different make files of the fab modules, that convert different file formats to G code for the MTM snap. They all contain
the similar constant values of federate and revolutions per inch that might need change in our future design.

 
                                      Electronics part           

                                       
          -RAMIN SHAMBAYATI wrote about the GRBL shield :To drive 3 stepper motors we found an existing design, called the GRBL Shield, done at MIT, which should do
the trick perfectly. The shield is essentially a triplet of Arduino compatible Easy Drivers and can be directly mounted on an Arduino. It uses A3982 drivers to power
each stepper and is powered with an external battery. There was an old one lying around the lab which we tested, and saw that it works by running a couple Arduino
sketches, the first one simple, and the other a bit more complex, after we worked out the ratios for steps to degrees, microsteps, pulses, and microseconds...
Given that one of the A3982's was missing and a few traces on this board were destroyed, we need to order new components, as we don't have many of them in our
 inventory. Once these arrive we can build a new board and run the 3 motors. I will also be making a similar board, if not the same for my final project as I plan to use
3 steppers. All the links to the useful pages are on the left! 

      This is the Arduino code mostly figured out by Jose (which worked with one driver). We based the code off this Bildr tutorial but had to tweak it to match our
specific motor as our stepper takes 400 steps for a full rotation.
 
    
       


MY PART

- This week i started to redesign the Barduino board we have to fit it in the motor shields we already finished repairing, i started by
adding the Arduino headers then arranged all the components
 around, didn't have enough time to test it and program it yet ,

                                               

  


  
>Proposal
   >Digital model

   >Laser Cutting
   >Electronic
         production

   >3D Scanning
         & Printing
  
>Electronic Design
  
>Molding & Casting
   >Embedded programing
   >Computer-controlled
  machining

   >Input devices

   >Composites