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Just as a reference, the last time this event was run, our boom used 4 main compression members that were 1/8 x 1/8, with each being @ .7g a piece.

MadCow2357 wrote:1/4" by 1/8", bout 2.5 grams per piece (I think). 1/8 by 1/8 is definitely too thin, and light balsa probably won't suffice.

We have very short "bracing intervals", so we are going to use light wood. We will try medium though.
What about the tension members? We currently are using 3/32 square and these work for us. Any suggestions?

-Sciencer

Sciencer101 wrote:

MadCow2357 wrote:1/4" by 1/8", bout 2.5 grams per piece (I think). 1/8 by 1/8 is definitely too thin, and light balsa probably won't suffice.

We have very short "bracing intervals", so we are going to use light wood. We will try medium though.
What about the tension members? We currently are using 3/32 square and these work for us. Any suggestions?

-Sciencer

3/32 balsa? Or bass? 3/32" square bass should work, but I'm going to try bumping it up to 1/8" square bass.

MadCow2357 wrote:

Sciencer101 wrote:

MadCow2357 wrote:1/4" by 1/8", bout 2.5 grams per piece (I think). 1/8 by 1/8 is definitely too thin, and light balsa probably won't suffice.

We have very short "bracing intervals", so we are going to use light wood. We will try medium though.
What about the tension members? We currently are using 3/32 square and these work for us. Any suggestions?

-Sciencer

3/32 balsa? Or bass? 3/32" square bass should work, but I'm going to try bumping it up to 1/8" square bass.

Balsa, we tried bass and it's WAY too heavy.

Sciencer101 wrote: Balsa, we tried bass and it's WAY too heavy.

What weight are you aiming for? I'm going for less than 10 grams, since I'm playing it safe at RI states. As I long as I don't bomb I can take gold with a decent score. So far, I've been using bass for my main tension members and my booms have always come out less than 8 grams. Not sure how bass is "too heavy". There is another advantage of using bass, which is well known but probably not that well understood: Bass sticks have pretty uniform tensile strengths throughout. And since the tensile strength of a member is only as strong as its weakest point, you're less likely to have a premature breakage in tension by using bass than by using balsa. That's because the strength of balsa can vary a ton throughout the whole piece.

I think bass is fine, but that's just my two cents on this particular issue.

MadCow2357 wrote:

Sciencer101 wrote: Balsa, we tried bass and it's WAY too heavy.

What weight are you aiming for? I'm going for less than 10 grams, since I'm playing it safe at RI states. As I long as I don't bomb I can take gold with a decent score. So far, I've been using bass for my main tension members and my booms have always come out less than 8 grams. Not sure how bass is "too heavy". There is another advantage of using bass, which is well known but probably not that well understood: Bass sticks have pretty uniform tensile strengths throughout. And since the tensile strength of a member is only as strong as its weakest point, you're less likely to have a premature breakage in tension by using bass than by using balsa. That's because the strength of balsa can vary a ton throughout the whole piece.

I think bass is fine, but that's just my two cents on this particular issue.

Bass is way heavier than balsa. For a balsa stick that is 36 inches it may weigh like 1 gram for 1/8 x 1/8 and for bass it can weigh maybe up to 3 grams per stick. You are right that it is stornger and more safer I suppose. But for your case for Rhode Island I think it’s a good idea.

MadCow2357 wrote:

Sciencer101 wrote: Balsa, we tried bass and it's WAY too heavy.

What weight are you aiming for? I'm going for less than 10 grams, since I'm playing it safe at RI states. As I long as I don't bomb I can take gold with a decent score. So far, I've been using bass for my main tension members and my booms have always come out less than 8 grams. Not sure how bass is "too heavy". There is another advantage of using bass, which is well known but probably not that well understood: Bass sticks have pretty uniform tensile strengths throughout. And since the tensile strength of a member is only as strong as its weakest point, you're less likely to have a premature breakage in tension by using bass than by using balsa. That's because the strength of balsa can vary a ton throughout the whole piece.

I think bass is fine, but that's just my two cents on this particular issue.

We are aiming for 5 to 6 grams, we tested bass for tension and compression but it was too heavy to meet our needs.
We just decided to increase the dimensions of the balsa wood. There was still a decrease in weight from bass to balsa.

The most difficult part for boomilever for me, is making it have a light weight and really strong at the same time for a pretty high efficiency. Does anybody have any feedback on this?

Does anybody know what type of wood most people at nationals use for boomilever to get efficiency up to 1000 or maybe 2000. (Balsa or Basswood.)

BilalHayat19 wrote:The most difficult part for boomilever for me, is making it have a light weight and really strong at the same time for a pretty high efficiency. Does anybody have any feedback on this?

well you wanna start high (in terms of weight) and go down. so if you start off with a fairly heavy boomi that holds all the sand, thats where you want to start. from there, increase the weight each time by increments until it breaks or doesnt hold as much sand as you would want it to. by then, you can either increase the weight again or try the same design, but with different bracing. always record your tests in slow motion to see where the device broke, which can allow you to solve a lot of your problems later on. i hope this helps.

I totally agree with klastyioer. However, I'm a little confused, why did you create a whole new topic for this question? Couldn't you have posted this in the main topic of our Boomilever forum?