Ongoing Contest(Scores)

[silverheart7]

I didn't watch boom, but that's not right. I have nothing against taking pictures, but people should ask first!

My rules on picture taking:
-Ask politely
-Don't touch
-And just be nice to me! I love to talk about my projects, but if you ask me rudely, I'll get scared (I'm sort of shy) or annoyed.

[mwloveslm]

I've had much more extreme ways of parents trying to see our designs.
One parent at a regional was in the seats and when I walked past her, she stopped me with her hand and examined it CLOSELY (Even touching it to move it around) to try to see what we did. (BTW this was towers from last year). In about 1 second, I snatched it away quickly (it was already broken) and power walked back and gave a quick excuse that "I had to go". Some people really go too far....

At states, a parent from a school that I didn't remember came all the way down from the stands to take a picture of each boom that was tested. After each boom was loaded (but not tested) he pulled his camera from his pocket, snapped a picture, put his camera away, then sneaked away like nothing happened.
Oh, yeah, and my score was:
Boom mass: 12.5 g
Amount held: 10600 g
Efficiency: 848

Yeah I just had my State competition on Saturday, my partner and I had an efficiency in the 1200's, but we got third place :/

[drifter601]

I've had much more extreme ways of parents trying to see our designs.
One parent at a regional was in the seats and when I walked past her, she stopped me with her hand and examined it CLOSELY (Even touching it to move it around) to try to see what we did. (BTW this was towers from last year). In about 1 second, I snatched it away quickly (it was already broken) and power walked back and gave a quick excuse that "I had to go". Some people really go too far....

At states, a parent from a school that I didn't remember came all the way down from the stands to take a picture of each boom that was tested. After each boom was loaded (but not tested) he pulled his camera from his pocket, snapped a picture, put his camera away, then sneaked away like nothing happened.
Oh, yeah, and my score was:
Boom mass: 12.5 g
Amount held: 10600 g
Efficiency: 848

Yeah I just had my State competition on Saturday, my partner and I had an efficiency in the 1200's, but we got third place :/

@mwloveslm
What was First or Second place at your state? 1200 at third is pretty good, soooo you have a comp0etitive state for boom!

[mwloveslm]

@drifter601
The first and second place scores were both in the 1300's, and after our 1200, the other team had 1100

[Balsa Man]

Socal scores were quite competitive. Scores above 850 scored in the top 10. Rumors were that Troy had a 7/8 boomi with 14 kg. They got 4th.

Wow! A 7.8 boomilever that held 14 kg only got 4th? That seems very hard to believe. That's about 1800 efficiency.

Anyway, what do people think the predicted Nats medaling range will be? The only thing that has been discussed has been the top score. I'm thinking: >1700 for div. b, and >1600 for div. c.

Div. C is not necessarily going to be harder. Although Div. B has it easier with their larger clearance, that causes more wood, which is more weight. soo I expect 1600 for both.

Why would you think that Div C isn't harder? Smaller clearances mean the the forces on the structures are higher, actually fairly significantly. And the lessened forces would mean that technically Div B can score higher, because they can use wood with much lower densities which would be a lot lighter. There are plenty of people that have scored over 1600 already in the season.[/quote]

As discussed before, both tension and compression forces in a B-boom are about 3/4 those in a C-boom. That gives you a sense of the difference in efficiences possible.

I just looked through the archived board and found the scores from the 2007 tournament. Here they are:

1. 6.85g / 15 Kg / 2189.8
2. 5.40g / 10.255 Kg / 1899.1
3. 8.00g / 15 Kg / 1875.0
4. 8.41g / 14.610 Kg / 1737.2
5. 7.42g / 12.880 Kg / 1735.8
6. 8.95g / 15 Kg / 1676.0

The specs were the same as the B-div. specifications for this year-- 20 cm below bolt, loading block between 40-45 cm.

Believe the height spec was 15- the same as for C- this year, not B.

Last, I'm curious on the take on Troy's "7-8" gr, and what sounds like guessing on weight- does anyone know what the weight was, because just looking won't get you there...

[havenguy]

Believe the height spec was 15- the same as for C- this year, not B.

That's what I thought as well, but after a quick look through the archived forum, I found several quotes that made it clear that the height max was 20 cm. Remember, this was the 2006-2007 season for boomilever, not 2007-2008. For instance:

Are you maxing out the 20 cm rule and the 40 cm rule?

[Balsa Man]

Ah, good point.
Yes, it was 2008 that was at 15 x 40- this year's C- spec, and 07 at 20 x 40- this year's B- spec. What i'm not sure of- could be wrong; I thought those results were for 2008 (don't have time today and dig back to check).

If those are 2008 results, that suggests someone in C- breaking 2000, and B- a bit higher is a reasonable possibility. If they're 2007, that suggests someone in B- breaking 2000 is a reasonable possibility, but much less likely for C-

[GeorgeInNePa]

"Tube" Boomilever

First try:
Boom weight-10.95g
Held-7714g
Efficiency Score- 704.5
Mounting block failure.

Second try:
Boom weight-12.25
Held-11316g
Efficiency Score-924
Tube failure due to alignment issues.

Third try will be under 12g and will hopefully hold more. We are learning with each build.

Third try (the boom from the first try with a new mounting block):
Boom weight-11.08
Held- 11512g
Efficiency Score- 1038.99
Tube failure.

[Balsa Man]

Good progress; you're making nice headway; very respectable score.
We're going to State Saturday. Our Team 2's boom is almost exactly same weight as your last one; Team 1's is.... lighter.

It's great to see folk in other places working with the tube approach. What sort of specs you running on your tubes? Rolled, or have you figured out another way? Ours are not rolled; made w/ 2 pieces. We're running 5/8" i.d., about 1/32nd wall; about 5.3gr tube weight in the 11.1 boom.

[GeorgeInNePa]

Good progress; you're making nice headway; very respectable score.
We're going to State Saturday. Our Team 2's boom is almost exactly same weight as your last one; Team 1's is.... lighter.

It's great to see folk in other places working with the tube approach. What sort of specs you running on your tubes? Rolled, or have you figured out another way? Ours are not rolled; made w/ 2 pieces. We're running 5/8" i.d., about 1/32nd wall; about 5.3gr tube weight in the 11.1 boom.

We're using a "rolled" tube. It's 1/16" balsa (there's no 1/32 available locally) wrapped around a 1/2" form. Single bass tension and a laminated balsa mounting block.

With the 1/16, we're running anywhere between 4.2-5.3grams for the tube.

This was a steep learning curve, my daughter wasn't doing boom, but decided to try it out after our team's booms were, ...disappointing...

Our States is next week.

I stole this tube idea from you, so a thank you is in order.