Project Pegasus Part 10: Rebuild Remix

Maddy, Lorenzo, and Jordan rebuild the new DB25 endcap

3/6/2018
San Diego, CA

​Project Pegasus has been a roller coaster of a ride since its inception last Spring (2017). After a long hiatus, we’re finally able to make the necessary repairs to get Pegasus back in the water. After a lot of head scratching and troubleshooting, we finally realized that the DB25 connector was fried. There about 25 different wires that provide power and information to Pegasus; think of the DB25 as the place where your skull meets your spine. One end of the DB25 is fixed in an “endcap” which seals off the e-chassis from the outside environment. The wires pass through the endcap and are dispersed across the body of Pegasus. The other end of the DB25 connector is mounted to the e-chassis, which is essentially Pegasus’s brain. All systems looked good after we rebuilt the starboard battery tube and controller board, but still Pegasus wasn’t turning on. Power simply wasn’t getting from the battery tubes to the e-chassis. It’s going to take us a little while to rewire Pegasus, which is easier said than done. Here’s Jordan had to say about our pre-rewiring prep:

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Solvent welding can by sticky business!

Maddy carefully applies solder the tops of the batteries

​“The ROV and our team have been through a lot over the past year or so. It was sad to see that our DB25 pin, which controls where all the power from the batteries go, was fried. This means that we will need to essentially rewire the majority of the ROV. It is OK though because soldering is one of the most interesting parts of the build! Wire management is also a big concern for our team. We debated over the best places to cut the wires in order to ensure the best wire management as well as least amount of soldered connections. 
 
Today we had to look up some old instructions and rebuild the end cap with a new DB25 connector that we got from OpenROV®. We had to revert back to solvent welding with the dropper that is slightly to wide to allow the liquid to drip slowly. We were able to solvent weld the pieces of plastic together and epoxy the DB25 connector in the end cap, in order to waterproof this portion.
 
After about 2 1/2 hours of work we realized that we had to wait at least another hour for the epoxy to dry before we could even start soldering the new joints, so we decided to save that for another day. We did, however, solder little pieces of solder onto the ends of the batteries so that they would stay in contact with each other in the battery tubes.”
 
Stay tuned! The team and I are meeting next week to rewire Pegasus and get it ready for its public debut at CMIL’s Marine Science Day!
 
Cheers,
 
-Baron von Urchin

Method in the madness: our team's "work station

Project Pegasus is about more than just building an ROV