User blog:Brandonlock1213/Fixing Our Blimp Lift Problem

Justin and I did some research into fixing our blimp lift problem. We needed to decide quickly because the backup plan was to purchase a larger blimp that would take 1-2 weeks to ship from Canada.

I sent over the data to Ryan at GA Tech, who quickly put together a spreadsheet that showed that under perfect conditions, we needed 4.18 cubic feet of helium to get 121g (the estimated weight of our components) of lift. The blimp has no tech specs, but people on forums online said that our blimp should hold 4.5 cubic feet of helium. Justin and I hypothesized that the discrepancy in lift must have been caused by either (1) air seeping into the blimp over time or (2) diluted helium. We did some research and found that both situations were very possible. In particular, because I did not completely deflate the blimp before inflating if for our last meeting, I was suspicious that hypothesis (1) may have had a large impact on our lift.

On Wednesday 11/24/10, Justin and I completely deflated the blimp and refilled it at CVS (Note: the easiest way to deflate the balloon is to use a straw). Our lift rose from the 80g we measured last meeting to 90g. It was an improvement, but our goal was over 120g of lift, so we completely deflated the blimp and refilled it at the DUC (we had no problems getting free helium from here). Our measurement showed we were now getting 95g of lift -- still not enough. Because I had to leave to catch a flight, we decided that purchasing the new blimp envelope would be the best decision to make.

Considerations:

Although we didn't measure the lift we were getting after filling up with helium at Kroger, Justin felt that the lift we were previously getting was much stronger. This seemed possible because we were getting 80g of lift a week after inflating the blimp at Kroger. We decided to still purchase the new blimp envelope though in case we were wrong. However, it may be beneficial to test the theory at some point.