The opto-endstops marked the very first parts I had to solder for this MakerBot.  Not having soldering anything more complicated than two wires together, this was an adventure and learning experience.  Here’s what I learned today:

• The 3-pin connectors used for two of the opto-endstops (on the Y-axis stage) are in the Generation 3 MakerBot Electronics Kit (Mostly Assembled) with some of the other connector bits.  I was a little confused about this for a while.
• It helps to lay out all the little bits in an organized fashion beforehand.
• Keep a long thin rigid stick handy for bending delicate leads into the circuit board holes.
• Although I read the RepRap electronics fabrication guide and found it helpful, I still felt a little lost.  I found the most effective way to solder the parts in was to:
  • Get the soldering iron good and hot
  • Put the leads through the holes
  • Bend the leads a little so that they stayed in place
  • Flipped the board over so the leads were sticking up
  • Touched the solder to where I wanted the joint
  • Gently stroked the solder with the soldering iron tip towards the joint
  • This process seemed to create a pretty good joint
• You’re going to burn a finger at some point, accept it.1
• This almost goes without saying, but go slowly.
• Check and double check the orientation and placements.
• I found it helpful to take a large sheet of aluminum foil and shape it into a tray.  This helped contain the parts I was working on and was a good way to catch the flying leads that I clipped off.

1. I burned two. [↩]