Monday, April 8, 2013

Robosapien V2 - Inferior Wiring

Robosapien V2 - Inferior Wiring

March 01 2013

It's now well understood that the Robosapien V2 experienced a Quality Control issue when it came to certain production runs and the Wiring Harnesses that were responsible for the Foot control boards as well as the Power cables from the battery compartments to the Motor Board.

For those who are experiencing this problem - take heart!  It can be solved!


I am going to prove here that a "hopeless" Robosapien V2 can be saved

Here's a good example of what I'm talking about, oone of the control cables that connect to the main control board of the Robosapien V2 from one of the legs.  

In this case, the wire has SEVEN (7) connectors, so it is from the RIGHT Leg:



As you can see, someone (before I got my hands on this unit) decided that the way to address the Robosapien V2 Inferior Wiring issue was to:
  • Cut the wire
  • Slip a piece of shrink wrap over the wire
  • Splice the wire
  • Shrink wrap the spliced wire
It seems to me that's a lot of work to only keep the robot alive for a little while longer.  

OK as a stop-gap measure...I guess..but the real issue with the Robosapien V2 Inferior Wiring problem was that the wires eventually disintegrated to the point where complete structural integrity was lost at a very important point and exactly where it was needed the most, where the wire physically met up with the DuPont connector.

How about a closer look - let's take the connector apart, shall we?  

<place close up photo of Dupont connector "locks" here>

Opening up a DuPont connector is a delicate affair.  It is accomplished by carefully lifting a tiny locking mechanism in the connector.  I used a little tool I have around that basically looks like a micro ice pick:

<place photo of tool here>

Here's the connector separated from the wiring harness:



This kind of connector has a dual-crimp strategy where one band of metal goes around the wire for "strain relief" while the other part makes the electrical connection. 



As you can easily see if you click on the above image, the "strain relief" part of the connector is totally non-existent.  The insulation that surrounds the wires and protects them (and provides half of the strain relief strategy) has literally disintegrated.  

As a consequence, the wires are flopping around in the connector and starting to break off a little bit, which is why they look "hairy" in this picture in the gap between the end of the shrink wrap and the beginning of the connector:


Here's another picture of the Robosapien V2 Inferior Wiring problem:


Bad news.  Something needs to be done.  

Well...how about a re-wire?

Ready


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