Boomilever B/C

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Unbihexium
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Re: Boomilever B/C

Post by Unbihexium » March 25th, 2013, 5:52 pm

juicemanman wrote:
Unbihexium wrote:
juicemanman wrote:Yeah, I have a hole in it. Of course I have a hole in it. But that's not where the problem is. The problem is in the connection between the tension members and the base.
Well really if you make a snug fit, and lie the edges of the tension up with the washer, and glue generously with ca it really won't break..
But I do do that, and it still breaks at about 10 kg.
No, are your tensions inside the base or just on top?
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Re: Boomilever B/C

Post by juicemanman » March 25th, 2013, 6:00 pm

Inside.
iwonder wrote:Were saying you should make a hole for each tension member as well. Have you read Aia's boom guide? It has descriptions with pictures of how to build a good base.
I read it, but I'm terrible with a drill. I've tried it, but I ended up breaking up the whole base. One hole is so much easier.
You can't read this. You mad bro?

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Re: Boomilever B/C

Post by Unbihexium » March 25th, 2013, 6:11 pm

juicemanman wrote:Inside.
iwonder wrote:Were saying you should make a hole for each tension member as well. Have you read Aia's boom guide? It has descriptions with pictures of how to build a good base.
I read it, but I'm terrible with a drill. I've tried it, but I ended up breaking up the whole base. One hole is so much easier.
Easier but it won't work.. You asked for help so that's what we told you.. If you don't want it to split,use a thin bit and then a larger one
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Re: Boomilever B/C

Post by sjwon3789 » March 25th, 2013, 6:18 pm

You really don't need to drill the two holes for the 2 tension members. You can just carve those out with an acto knife. You can drill the center hole though, obviously... xPPP.
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Re: Boomilever B/C

Post by juicemanman » March 25th, 2013, 6:51 pm

Unbihexium wrote:
juicemanman wrote:Inside.
iwonder wrote:Were saying you should make a hole for each tension member as well. Have you read Aia's boom guide? It has descriptions with pictures of how to build a good base.
I read it, but I'm terrible with a drill. I've tried it, but I ended up breaking up the whole base. One hole is so much easier.
Easier but it won't work.. You asked for help so that's what we told you.. If you don't want it to split,use a thin bit and then a larger one
Thanks, I'll try it, maybe get someone else to help drill it.
You can't read this. You mad bro?

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Re: Boomilever B/C

Post by hogger » March 25th, 2013, 8:09 pm

I drill with the smallest bit I have and use a small precision file and carefully widen the hole in a triangular matter as pictured in Aia instruction. Also glue the triangular pieces to the end of tension members and I believe the gorilla glue should be used for this connection. Gorilla glue expands and fills all the gap and crevices.

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Re: Boomilever B/C

Post by leeumpetro » March 26th, 2013, 8:16 am

do you guys think its a good idea to recycle a previous boomilevers?

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Re: Boomilever B/C

Post by Unbihexium » March 26th, 2013, 8:43 am

leeumpetro wrote:do you guys think its a good idea to recycle a previous boomilevers?
No, because even any sort of transient stress will weaken the structure permanently. Always rebuild boomilevers, also this allow you to practice your building technique such that they improve with each build.
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Re: Boomilever B/C

Post by iwonder » March 26th, 2013, 9:29 am

I would say that I depends... Rebuilding is a good practice in techniques and forces you to get better. However it really depends on how close to the failure point you come. I have a boom from earlier in the season that I've used at 3 competitions and tested about 6 times, it still holds the 15kg just fine. Of course, this probably means that it's significantly over engineered, but if you don't come close to failure point of the boom and it works after a couple tests chances are it's fine.

A few people(me included) actually use this to check for major build errors. I test booms up 7.5kg or thereabouts before I take them to contest(called preloading, I believe) to make sure I don't have any air in glue joints or some mistake that could cause a premature failure. This has proved helpful at one contest, actually, where I had a boom fail at 3kg in testing becuase of a bad distal end joint, which I was able to repair and at contest the compression member buckled and it held 12kg.
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Re: Boomilever B/C

Post by _HenryHscioly_ » March 27th, 2013, 5:47 pm

1/16"x3/32" bass tensions
broke at 9.4kg
My boomilever stretched a lot. Sagged more than 1/4". I had a horizontal metal rod with books on the side, and an eyebolt attached to the top of the loading block; I had to open the book and use less pages to lower the rod.
This is normal...?? Is this set-up not correct?

I am a very slow worker..(hw, building, eating, lol, anything)
Tested single I beam, 4 stick compression, two stick compression, box beam, but only built 1 or 2 of each before quitting and changing design...
All were underbuilt
I have 1week...so built way overbuilt compression box beam(1/2"x1/8" sides 1/8"x1/8") braced into 4 section on horizontal plane.
Instead of using 3/32"x3/32" bass, which is what I've been using before, I went thinner to 1/16". The tension member sheared at the distal end. I only used gorilla super glue and increased the glue surface a tiny bit with a small piece of 1/16"x3/32" bass. The tension member didnt shear off the beam, but itself had a break almost parallel to its length.
weighed 18.63g..(had my partner build the box beams). I've been quite reserved because he built sloppily and seemed very rough, often accidentaly breaking pieces of wood and what not, but I think after teaching him to cut balsa sticks from sheet and glueing some stuff under my watch, he's getting more better and is more careful. Hopefully we can pick up our build speed and build quicker..
Hopefully he is ready, and we can start building smaller box beams and test. :]
Anyone else used 1/16"x3/32" bass?

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