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Re: Boomilever B/C

Posted: March 29th, 2014, 12:47 pm
by iwonder
Ok, so where are the tension members connected to the compression members in relation to the loading block and bolt. It sounds like either that or your compression member is too weak (you might be using really low density wood which is a lot weaker even though it's the same size)

Re: Boomilever B/C

Posted: March 29th, 2014, 2:15 pm
by nxtscholar
We had bracings connecting the tension and compression members to deal with vertical buckling, yes. Vertical? Yes.

As for your second question it's essentially like a warrern truss.

Re: Boomilever B/C

Posted: March 29th, 2014, 5:03 pm
by flyingwatermelon
@iwonder http://imgur.com/MiPv3rZ The block fits up to the pencil mark

@nxtscholar I'm going to PM you because it seems we have similar ideas :)

Re: Boomilever B/C

Posted: March 29th, 2014, 6:25 pm
by iwonder
Yeah, the tension members need to move so that the bolt fits along that pencil line. What you're getting now is that diving board effect I mentioned in the post above yours. (That probably means it needs to be wider, sadly)

Re: Boomilever B/C

Posted: March 31st, 2014, 7:24 pm
by flyingwatermelon
Cool! I fixed the issue now, but now it seems its causing some curvature in the compression members which is causing the tension members to dislocate from the base. Right now I have 3 1/8" balsa sticks on either side of the base that hold it to the tension members...is that enough? Or should I switch to bass

Re: Boomilever B/C

Posted: March 31st, 2014, 8:16 pm
by nxtscholar
This is coming from my event supervisor actually. He said that if the boom should happen to fail, and it fails such that the tension members are dislocated at the base, then you did a pretty good job in general.

But maybe someone could elaborate? :P

Re: Boomilever B/C

Posted: March 31st, 2014, 9:12 pm
by Azn
In a boom the compression member is the heaviest part. Therefor a compression failure should be the most ideal. Is it possible your event supervisor meant that an efficient failure incorporated a compression failure along with the tensions ripping out? This makes sense, since in an ideal situation every single part of the boom would fail simultaneously (of course this would never actually happen). The point is that no part of the boom adds unnecessary weight.

Re: Boomilever B/C

Posted: April 5th, 2014, 11:50 pm
by _HenryHscioly_
1180 and got 7th. no medal. ._,
first time i broke 1000 at competition.....

Re: Boomilever B/C

Posted: April 6th, 2014, 5:45 am
by Can_Of_Tuna
So, when the manual says that the mounting hooks are supposed to be and inch out, does it mean an inch from the tip of the hook, or from the tip of the shaft?
Because our testing wall has it from the hook, but the one at regionals was from the shaft

Re: Boomilever B/C

Posted: April 6th, 2014, 8:09 am
by Scioly99
Can_Of_Tuna wrote:So, when the manual says that the mounting hooks are supposed to be and inch out, does it mean an inch from the tip of the hook, or from the tip of the shaft?
Because our testing wall has it from the hook, but the one at regionals was from the shaft
It means 2.5 cm (about 1 inch) from the wall to the closest edge of the hook. Here is a link to more info: http://www.soinc.org/sites/default/file ... lation.pdf