Ongoing Contest(Scores)

[fanjiatian]

i'm in awe right now, those scores...

To UQOnyx: Water?
In all honesty, it doesn't really matter what you use as long as you distribute the weight at an even rate.

[UQOnyx]

I might just use water but I am afraid that it will spill when the boom deflects

[havenguy]

DIVISION B - SOLON Inv: 989 is is pretty decent score, correct? Well, it took that just to to get 8th place at the Solon Invitational! Winning score was over 1300... 2 teams in the 1200's 1 team in the 1100's, 5th place was 1033. Pretty amazing competition! I heard rumors that 7 of last year's top 10 National competitors were in attendance. Tough, tough competition!

*choke*

That's amazing...well, better get to work

@UQOnyx: maybe use rice? It's not very heavy, and water would probably be better. Just an idea...

[jyman]

At the JC Booth inv., Booth A had a score of 1450 and Solon B had a score of 1425. Solon A did not compete were reasons that were not known (Solon B had 2 backups so they probably did not want to give their design out.) I somehow got third with a score of 800 just above the other teams.

[marissaguts]

Be aware it is said that solon's efficiency has been beaten

[quizbowl]

Be aware it is said that solon's efficiency has been beaten

[Balsa Man]

i'm in awe right now, those scores...

To UQOnyx: Water?
In all honesty, it doesn't really matter what you use as long as you distribute the weight at an even rate.

Impressive scores, for sure.

Water can work well. A really nice thing is that one liter = one kilogram. Once you have a weight on bucket/chain/block/eyebolt, amount of water added tells you exact weight, w/o having to have a scale that's accurate to 15kg. A number of easy ways to control spill/splash. Set things up so even with the boom breaking, the bucket can't fall very far - like a couple inches off the ground at the start. And/or put a lid on, with hole cut out to pour into. That way you have a lip, say 2-3 inches wide all the way around that catches/stops splash. You can even set up a funnel in the hole in the lid.... And, of course, if you use a safety chain/hookup above, so even in total failure the load block can only drop....1/2 inch/quarter inch, no splash problems.

"Distributing the weight"..... has nothing to do with anything. Water will distribute itself, as in the surface of the water will be flat. Even using a solid material; sand, gravel, etc., the distribution does NOT matter. It can be stacked up against one side, with the bucket tilting to that side, and the pull, from the single point of attachment, is still straight down. I and others have said this many times over the years. I have to chuckle everytime I see someone using a sheet of paper, as the sand goes in, trying to distribute the load so the bucket is level. Not only does it do nothing, it risks bumping the bucket/chain, which really can/does cause a problem. Even rate, yeah, nice, but the key is avoiding shock loading.

Speaking of testing with water, we finally got to a full structure test over the weekend. Only a couple of hours to to put the boom together- a LOT of hours getting the tooling/jigs to do precision building designed and built.
Ran it to partial load; just taking it to a hair over 1,000 points. Steady as a rock- that was a big question on a single t-member/single c-member setup. The tension member stretch was consistent with what we'd seen in earlier t-member testing. With a single t-member, there is a fair amount of elongation at full load. The compression tube started off with a bit of an up angle, above horizontal. As we got to 1,000 point loading , angle had decreased to a bit above horizontal - right where it was supposed to be. Straight edge check along the compression member showed zero bending. So, into the box, ready for Regionals. After Regionals we'll take it to destruction, and base how much we then go down in weight for State on that.

[iwonder]

I think the main reason people use a sheet of paper and try to distribute the load is because they're afraid of the bucket jerking all of a sudden which could definitely jar the structure and cause a premature failure. Of course, if you're remotely careful pouring this is a non-issue.

[UQOnyx]

i'm in awe right now, those scores...

To UQOnyx: Water?
In all honesty, it doesn't really matter what you use as long as you distribute the weight at an even rate.

Impressive scores, for sure.

Water can work well. A really nice thing is that one liter = one kilogram. Once you have a weight on bucket/chain/block/eyebolt, amount of water added tells you exact weight, w/o having to have a scale that's accurate to 15kg. A number of easy ways to control spill/splash. Set things up so even with the boom breaking, the bucket can't fall very far - like a couple inches off the ground at the start. And/or put a lid on, with hole cut out to pour into. That way you have a lip, say 2-3 inches wide all the way around that catches/stops splash. You can even set up a funnel in the hole in the lid.... And, of course, if you use a safety chain/hookup above, so even in total failure the load block can only drop....1/2 inch/quarter inch, no splash problems.

"Distributing the weight"..... has nothing to do with anything. Water will distribute itself, as in the surface of the water will be flat. Even using a solid material; sand, gravel, etc., the distribution does NOT matter. It can be stacked up against one side, with the bucket tilting to that side, and the pull, from the single point of attachment, is still straight down. I and others have said this many times over the years. I have to chuckle everytime I see someone using a sheet of paper, as the sand goes in, trying to distribute the load so the bucket is level. Not only does it do nothing, it risks bumping the bucket/chain, which really can/does cause a problem. Even rate, yeah, nice, but the key is avoiding shock loading.

Speaking of testing with water, we finally got to a full structure test over the weekend. Only a couple of hours to to put the boom together- a LOT of hours getting the tooling/jigs to do precision building designed and built.
Ran it to partial load; just taking it to a hair over 1,000 points. Steady as a rock- that was a big question on a single t-member/single c-member setup. The tension member stretch was consistent with what we'd seen in earlier t-member testing. With a single t-member, there is a fair amount of elongation at full load. The compression tube started off with a bit of an up angle, above horizontal. As we got to 1,000 point loading , angle had decreased to a bit above horizontal - right where it was supposed to be. Straight edge check along the compression member showed zero bending. So, into the box, ready for Regionals. After Regionals we'll take it to destruction, and base how much we then go down in weight for State on that.

May I ask how much the boom weighed or is that too personal?

[Balsa Man]

May I ask how much the boom weighed or is that too personal?

Of course.....
All I'm going to say, though, till we get closer to Regionals, is well under 15g