We're under budget! ... Mass wise at least

Hey, it’s Cassidy from mechanical again.

The last few weeks have been crazy. Most of my time has been spent constructing and deconstructing the PCB structure, between extensive amounts of filing. The mechanical department has even adopted, or stolen depending on who you ask, two new members from other departments. Daniel, who helped us out during manufacturing and assembling, especially when we spent about 3 days continuously filing. And John, who helps assemble and just generally solve problems. Including his most recent simple, yet genius, idea for a DSUB adapter plate that works beautifully.

 The PCB structure is coming along.

 

But besides filing and assembling, we’ve also done some pretty cool stuff like the ejection test, where we had to get creative with tube covers.

 The first ejection test took a bit of work before it was functional, but we got there eventually thanks to electrical.

 

And the vibration test, which will still require some tweaks before we retest the PCB structure. At a certain frequency the nuts start to unscrew themselves. While this is kind of fun to watch, we’d prefer that the structure doesn’t completely fall apart.

 The vibration setup before all the chaos began.

 

These hectic few weeks have all been for one goal. Sending the experiment to Germany for integration week. We cut it very close, but finally at around 2am on the day the experiment was set to ship out, we were able to weigh an assembled experiment for the first time.

 The assembly process takes a while.

 

The BESPIN experiment is not allowed to weigh over 9kg. Before descoping, we were estimated to be about 12kg, so mass has been a big issue for us. The mass budget has been my responsibility from the beginning. It reached the point where every time we drilled a hole in anything I’d be excited because less material = less mass. The opposite is also true. I cringe every time a longer screw than was previously thought is needed or if glue is added. This obviously has led to a decent amount of teasing from the other members of the team. Based on all the past mass issues, I was dreading putting the experiment on the scale. Shockingly, the scale read 7.94kg, 600g less than anticipated.

 An unexpected outcome that I still don’t quite believe.

 

As opposed to being thrilled with this news, we were slightly concerned and spent the next 15 to 20 minutes trying to figure out what was missing. After taking into account the few missing things that we were already aware of, we rationalized that we had everything in the experiment that we possibly could and that we didn’t just leave out a part of the structure. Now the joy started to kick in, or it could have just been the massive amount of sleep deprivation we were all experiencing. We were under mass. After months of worrying it was a relief. While we still have to reweigh the experiment with all the flight hardware, I’m feeling much better about the mass limit.

So now the experiment is snuggly packed and off the Bremen for integration week, but I’m sure you’ll read about that in the upcoming blog posts.

 

Until next time,

Cassidy

 

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