Boomilever B/C

[vince21298]

hey new to this site. any tips for designs?

[thsom]

Just saying, does anyone know what the winning nats score in 2008 was?

I don't have the National's data available, but the winning score at the Ohio State tournament should be somewhat comparable. It was 1113 points.

Really, seems low to be equivalent that of the winning nats score.

[chalker]

Really, seems low to be equivalent that of the winning nats score.

Really? Let's assume that the team held the full load of 15kg. That means the boomilever weighed 15000g / 1113 = 13.4 grams. That seems to be a pretty reasonable weight for a device 40cm long at minimum. While the national score might have been a bit better, I can't imagine it being significantly different.

[JimY]

The winning efficiency at nats in 2008 was closer to 2500. It was about a 6 gram boom that went to full load. A Kansas school won the event in both 2007 and 2008. In 2007, it was by a wide margin. It was much closer in 2008. At least this is what I recall. So, quite a bit better than Ohio at the time.

So, do your schools typically keep their best devices to start from when an event comes around again or have some other means of not recreating the wheel when an event comes back, or do you start from scratch?

[fishman100]

I don't know about 2008, but I believe that the winning efficiency in 2007 was also around 2500; if memory serves it weighed 6.18 grams and held full. The 2nd place boom weighed ~5g and held ~10kg.

So, do your schools typically keep their best devices to start from when an event comes around again or have some other means of not recreating the wheel when an event comes back, or do you start from scratch?

For the "balsa building events" we usually have to start from scratch since there are 3 event rotations, so by the time one "cycle" (2 years of towers, 2 years of bridges, and 2 years of booms) has been completed, the designs have been lost, thrown away, or kept at home.

We did find 2 booms from 2007, including the one that our school took to nats that year, but since the specs are different we can't really use them as a template.

[chalker]

The winning efficiency at nats in 2008 was closer to 2500. It was about a 6 gram boom that went to full load. A Kansas school won the event in both 2007 and 2008. In 2007, it was by a wide margin. It was much closer in 2008. At least this is what I recall. So, quite a bit better than Ohio at the time.

So, do your schools typically keep their best devices to start from when an event comes around again or have some other means of not recreating the wheel when an event comes back, or do you start from scratch?

Thanks for the info. Looking at the posted final 2008 results (http://soinc.org/sites/default/files/up ... ll_C08.pdf), Kansas team 26 did indeed get 1st, while Ohio team 7 got 35th in the event (although 3rd overall in the tournament).

Everyone should please keep in mind there is at least 1 significant change from the rules in 2007-2008 and now that will likely impact the abilities of the boomilevers. In 2007-2008 the device could be up to 20cm below the attachment holes. That's still true in B division, but in C the limit is now 15cm.

[icyfire]

New to this event and just want a tiny clarification on the wording from the rules.

"The Testing Wall must have three mounting holes for 1/4" bolts, horizontally aligned....and the center of the other holes placed 10.0cm from the center of the middle hole... 3 sets of bolts must be provided to attach the Boomilever to the testing wall."

Isn't there just one hole on the Boomilever attachment base that is used to attach it to the testing wall? How come there are two more holes on the testing wall and 3 sets of bolts in total?

[iwonder]

You don't have to use every hole, so just use the middle one, that's what most people do.

[juicemanman]

Uh, just asking, but does the mass of the bolt count as part of the mass of the boomilever?

[thsom]

Uh, just asking, but does the mass of the bolt count as part of the mass of the boomilever?

no but the mass of the base does