Physics Lab B/C

[mrcadman]

Remember, everything is relative. We have several motors from different CD players and even a matching pair. None measure the same voltage, and a couple measure only half that the others do. You'll know you have a winner when you have to reduce your Tip Speed Ratio just to keep it on the hub.

[SSANationalTeam1]

How well do 2 bladed ones do?

based on my testing, they tend to be more efficient than the 3-bladed designs...

I can confirm this.

as can I

[Epicfail]

kv1296 wrote:

Piggybacking off of illusionists post (I'm his partner). Our score was the highest at regionals, but I'm sure that that kind of score would be average at states. Any other Michiganders getting comparable speeds? Or any other B team for that matter.

im from MI and in B but we only got like a 695...how are you getting so high? what design are you using? we're using 3 blades made of cardboard...have to tap it. there's no slant.

[Greg Doe]

If anyone is interested, here are the results from the Tennessee state competition, Sat. Mar. 27.
B Division: 1st, Bearden Middle School; 2nd, Harpeth Hall Middle School; 3rd, St Rose of Lima
Catholic School. C Division: 1st, Harpeth Hall Hich School.
Those following this thread might remember that back on Mar. 23 I promised to report back on the
outcome. I was on the other side of the campus in the HPER Gym where Wright Stuff was being
contested most of the day. By the time I got back to the classroom where Physics Lab was
conducted the results were taken down, so I had to depend on the students, and a parents memory.
Both the 2nd, and 3rd place teams in "B" out performed the first place team on voltage, but they were out scored on the written test. Congratulations to Bearden, they did there homework. Our "joint venture" netted 2nd, and 3rd in B division, and 1st in C division.
Overall voltage output was low, probably due to the equipment and setup. At one point one of
the "B" generators slowed down and stopped as though it had dirt in it? It was restarted, and
apparently that fixed it.
The professor in charge of the event was so impressed with the St. Rose turbine that he called all the judges together to examine it, and proceded to tell them that this was what a turbine for this event should look like! Bearden finished 1st overall, my middle schools finished 7th and 8th. Good luck to all those who have competitions coming up. We're done.
Greg Doe
Smyrna, TN

[kv1296]

kv1296 wrote:

Piggybacking off of illusionists post (I'm his partner). Our score was the highest at regionals, but I'm sure that that kind of score would be average at states. Any other Michiganders getting comparable speeds? Or any other B team for that matter.

im from MI and in B but we only got like a 695...how are you getting so high? what design are you using? we're using 3 blades made of cardboard...have to tap it. there's no slant.

If you look at the earlier posts you can see that most people vouch for a two-bladed design as do we, and we also use cardboard for ours. So you can try something along those lines. Although I am curious at the design Wind Mentor uses.

[Epicfail]

We also have a 24-blade design that we haven't tested yet and a 8-blade that we haven't tested yet but we never thought of a two-blade. would the two blades be wide or...? Because two blades won't really take advantage of all the air.

[blue cobra]

I'd recommend going back and reading this thread. It seems since you're just going for pure speed, many people find success with very small, light designs with narrow blades. I don't know everything about it, but I guess since real windmills want the most power, not voltage, what's good for them isn't always good for us.

[Epicfail]

Thanks for the help but i thought the goal was to get the highest voltage (and do good on the test).

[blue cobra]

Higher speed=higher voltage

[EileenofSD]

Okay, so, we just got back from States and this was the easiest SciOly test I had ever taken. It was all multiple choice and even though our fan failed on low speed due to the mount they used, we managed to get 100% on the testing portion and take the gold. -victory dance-
Honestly, I knew all of it from my phys sci class, and a lot of the basics from Shock value and Crave the Wave were on there too. It was more of a warm-up than anything. I was like, "where's the real test?"

Edit;; For those wondering, our fan was as two-bladed balsa wood thing my partner spent hours on. Because I fail at building, and he's amazing at it.