Rotor Work!

It was another day back in the shop today and I got to experience rotor construction (the others helped turn coils and weld more)! We poured a foam mold for a second rotor today (the blade assembly is one rotor with 2 blades, all in one piece). This involved cutting fiberglass rotor shapes from a template out of a square shaped piece of fiberglass and then put them in the molds to add the

foam mixture. We bolted the mold together and added the mixture. It was an exothermic chemical reaction and created a sponge candy type consistency of material.

Photos left to right: template tracing on fiberglass sheets, prepping mold for foam, ready for foam before putting the two pieces together:

 

(I have a video of pouring the mold, but it won't rotate and isn't that stimulating unless you really enjoy chemistry and want to see a bottle expand with the excess materials.)

Then, we helped the others put carbon fiber on the rotor that was made yesterday. It was a sheet of carbon fiber weaved together that we needed to sew together around the rotor using carbon fiber strings. This took a long time to complete, and in the meantime, we ate lunch (I had a chicken and rice dish) and came back to our mold which set after 2 hours. Once our rotor was set, we removed the mold, cut away the excess foam and sanded the rotor a bit in preparation for a carbon fiber covering that we will do tomorrow.

Black carbon fiber was sewed over the foam rotor

We also prepped the mold for the resin injection of the first rotor. This involved waxing the mold a few times, adding alcohol of sorts to the mold, cutting more fiberglass rotor shapes and adding silicon to the outsides of the mold to ensure an air tight seal when we finally put the molds together.

Once the carbon fiber cover was finished on the first rotor and the mold was ready, we placed the rotor in the mold again, and proceeded to make this mold air tight. The reason this needs to be airtight is because the resin that will be injected will be spread out in a vacuum system. To keep this mold air tight, we put an amazing amount of clamps on the outside, bolted the mold together, hot glued over all the bolts and then hot glued the cracks where the two molds came together. Then we cut some tubes to connect to the vacuum contraption that will draw the resin through the rotor mold. We’re doing this tomorrow, so I’ll have more info on it then.

Resin injection mold is sealed shut

Before we prepped the resin injection mold, I helped work on the magnetic rotor disk which helps make up the alternator. This was particularly interesting because the magnets we needed to place had to be opposite poles in the center of the circle, so if one was north in, the next had to be north out, etc. We checked each magnet every time and once we got to the 6^th magnet, we rechecked and there was only one magnet that was north in. We could tell by holding another magnet above all of the placed magnets to make sure it’s the opposite pole in. Finding this issue was strange because it was as if the magnets completely changed polarity. It was pretty interesting because we super glued the 5 previous magnets to the magnet bottom piece, so it was difficult to get them off the plate that had resin on it. We redid the resin that was on the disk, and let that set and will revisit this tomorrow.

Magnetic rotor disk assembly

We got back to the house, and had dinner (potatoes, veggies and some sort of tofu), and just as we finished, the power went out! It doesn’t seem a rarity, but it also doesn’t seem like it’s common. I’m super happy I brought my solar powered lantern from the Clarkson Sustainability Day because I brought it out immediately and it allowed us to play cards before going to bed! The power being out is also why I’m late in posting this blog; no power, no wifi. It was out for about an hour and a half.

It's super awesome I got to experience so much today! Looking forward to continuing tomorrow!