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Re: Boomilever B/C

Posted: September 27th, 2020, 2:34 pm
by bernard
sneepity wrote: September 27th, 2020, 1:50 pm
Umaroth wrote: September 27th, 2020, 12:54 pm
Godspeed wrote: September 27th, 2020, 12:06 pm

Wait but how does that work? if It's on the hook, then it's guaranteed to be in between the contact width lines, right?
But it's not touching the wall, it's touching the hook
It'll have to hang from the hook, so it's not the wall. All other parts will have to touch the wall for the boomi to carry the load.
It's worth mentioning that the hook is only the hook. The hex nut and washer are considered part of the Testing Wall per the bold text in 5.a.iii.

Re: Boomilever B/C

Posted: September 27th, 2020, 7:10 pm
by Godspeed
Umaroth wrote: September 27th, 2020, 12:54 pm
Godspeed wrote: September 27th, 2020, 12:06 pm
AstroClarinet wrote: September 27th, 2020, 4:29 am

Rules 3.d and 4.e.III say that no part of the boomilever can touch between the contact width lines. The contact width lines also extend fully up the testing wall per 5.a.v. So I would say that the hook part of the boomi also can't touch the wall between the lines.
Wait but how does that work? if It's on the hook, then it's guaranteed to be in between the contact width lines, right?
But it's not touching the wall, it's touching the hook
Oh ok thanks.

Re: Boomilever B/C

Posted: September 28th, 2020, 4:37 pm
by 123445
Hey guys! So a problem I had last year (which I never got to solve because scioly was canceled) was that I wanted to keep the base of my boomi small so it fit the hook perfectly, but then I wasn't able to add any vertical members towards the end with the 8cm width requirement. Any suggestions on how to keep the base somewhat narrow while still being able to add vertical members?

Re: Boomilever B/C

Posted: September 28th, 2020, 8:55 pm
by Godspeed
123445 wrote: September 28th, 2020, 4:37 pm Hey guys! So a problem I had last year (which I never got to solve because scioly was canceled) was that I wanted to keep the base of my boomi small so it fit the hook perfectly, but then I wasn't able to add any vertical members towards the end with the 8cm width requirement. Any suggestions on how to keep the base somewhat narrow while still being able to add vertical members?
I honestly don't think you can actually keep the base small without adding vertical members. If anything else, it would be to just add more bracing to the compression part of your boomi (considering you're using a tension boomi.)

Re: Boomilever B/C

Posted: September 29th, 2020, 4:59 am
by sneepity
123445 wrote: September 28th, 2020, 4:37 pm Hey guys! So a problem I had last year (which I never got to solve because scioly was canceled) was that I wanted to keep the base of my boomi small so it fit the hook perfectly, but then I wasn't able to add any vertical members towards the end with the 8cm width requirement. Any suggestions on how to keep the base somewhat narrow while still being able to add vertical members?
Having the base fit the hook perfectly is great, but I think you should make it a little wider, just enough to not let the base fail due to shear. Another factor is the size of the vertical members- I suggest keeping them relatively flat or skinny compared to the tension and compression members. But when I've had this problem too, I just bent my sticks a very tiny bit. I suggest trying it out and seeing if bending it could cause early failure, it could provide some insight into this :)
Edit: I think the hook is ~1cm -/+, so base should be 2-3 cm. Depends on your design, you could make it smaller or bigger

Re: Boomilever B/C

Posted: September 29th, 2020, 6:33 am
by SergioEdwards
Hi everyone! I've been struggling with guaging what a good weight is. Im fighting myself to keep it light but am paranoid that Im not putting enough glue. What do your guys' bases usually weigh? Im really not sure how mine compares. Last year mine were 20+ grams but over the summer I made a couple prototypes that were around 6 grams. If anyone has any input, I would love to hear it.

Re: Boomilever B/C

Posted: September 29th, 2020, 7:36 am
by sneepity
SergioEdwards wrote: September 29th, 2020, 6:33 am Hi everyone! I've been struggling with guaging what a good weight is. Im fighting myself to keep it light but am paranoid that Im not putting enough glue. What do your guys' bases usually weigh? Im really not sure how mine compares. Last year mine were 20+ grams but over the summer I made a couple prototypes that were around 6 grams. If anyone has any input, I would love to hear it.
So CA glue is super strong with bonding wood fibers, and just any surface and material. I really don't think that you would need over the amount that you can get by taking two pins and joining them together at the sharp side, and dipping it into the glue to pick some up. As a matter of fact,too much glue could also lead to failure, due to CA glue acting as a plastic,which could actually prevent some necessary balancing forces to act out, causing the joint or whole boomi to fail. And also,for your weight for the base (the compression members plus the cross members),I suggest you try all sorts of designs out. I highly suggest taking a look at bridge truss types (even though it's for bridges,it should help you out with design). And keep testing them to see which ones were the lightest and most efficient- skinnier sticks, less bracing,etc could all make your boomi's base lighter. And finally, mine were ~4 grams, and the ones that were heavier were a little more (about 4.5g,etc). But to get the right boomi, testing is very important! I wish you good luck in your testing :)

Re: Boomilever B/C

Posted: September 29th, 2020, 8:11 am
by SergioEdwards
sneepity wrote: September 29th, 2020, 7:37 am
sneepity wrote: September 29th, 2020, 7:36 am
SergioEdwards wrote: September 29th, 2020, 6:33 am Hi everyone! I've been struggling with guaging what a good weight is. Im fighting myself to keep it light but am paranoid that Im not putting enough glue. What do your guys' bases usually weigh? Im really not sure how mine compares. Last year mine were 20+ grams but over the summer I made a couple prototypes that were around 6 grams. If anyone has any input, I would love to hear it.
So CA glue is super strong with bonding wood fibers, and just any surface and material. I really don't think that you would need over the amount that you can get by taking two pins and joining them together at the sharp side, and dipping it into the glue to pick some up. As a matter of fact,too much glue could also lead to failure, due to CA glue acting as a plastic,which could actually prevent some necessary balancing forces to act out, causing the joint or whole boomi to fail. And also,for your weight for the base (the compression members plus the cross members),I suggest you try all sorts of designs out. I highly suggest taking a look at bridge truss types (even though it's for bridges,it should help you out with design). And keep testing them to see which ones were the lightest and most efficient- skinnier sticks, less bracing,etc could all make your boomi's base lighter. And finally, mine were ~4 grams, and the ones that were heavier were a little more (about 4.5g,etc). But to get the right boomi, testing is very important! I wish you good luck in your testing :) accidental double post,I am so sorry!
Wow thank you so much! Its my dream to get a boom of 4 grams lol. Are these able to hold all of the weight? With the bonus it seems worth it to hold it all and I was wondering if that's how other people feel as well.

Re: Boomilever B/C

Posted: September 29th, 2020, 8:22 am
by JonB
SergioEdwards wrote: September 29th, 2020, 8:11 am
sneepity wrote: September 29th, 2020, 7:37 am
sneepity wrote: September 29th, 2020, 7:36 am
So CA glue is super strong with bonding wood fibers, and just any surface and material. I really don't think that you would need over the amount that you can get by taking two pins and joining them together at the sharp side, and dipping it into the glue to pick some up. As a matter of fact,too much glue could also lead to failure, due to CA glue acting as a plastic,which could actually prevent some necessary balancing forces to act out, causing the joint or whole boomi to fail. And also,for your weight for the base (the compression members plus the cross members),I suggest you try all sorts of designs out. I highly suggest taking a look at bridge truss types (even though it's for bridges,it should help you out with design). And keep testing them to see which ones were the lightest and most efficient- skinnier sticks, less bracing,etc could all make your boomi's base lighter. And finally, mine were ~4 grams, and the ones that were heavier were a little more (about 4.5g,etc). But to get the right boomi, testing is very important! I wish you good luck in your testing :) accidental double post,I am so sorry!
Wow thank you so much! Its my dream to get a boom of 4 grams lol. Are these able to hold all of the weight? With the bonus it seems worth it to hold it all and I was wondering if that's how other people feel as well.

SergioEdwards- I believe that 4 grams was referring to the "base", not the entire boomi (sneepity, correct me if I am wrong). I do not think we will see a 4 gram boomi hold full weight in either division but stranger things have happened this year.

Re: Boomilever B/C

Posted: September 29th, 2020, 8:24 am
by sneepity
JonB wrote: September 29th, 2020, 8:22 am
SergioEdwards wrote: September 29th, 2020, 8:11 am
sneepity wrote: September 29th, 2020, 7:37 am
Wow thank you so much! Its my dream to get a boom of 4 grams lol. Are these able to hold all of the weight? With the bonus it seems worth it to hold it all and I was wondering if that's how other people feel as well.

SergioEdwards- I believe that 4 grams was referring to the "base", not the entire boomi (sneepity, correct me if I am wrong). I do not think we will see a 4 gram boomi hold full weight in either division but stranger things have happened this year.
yeah lol, I meant only the compression members and the members that connect the compression members. I do not believe that a 4 gram boomi can hold full weight, but if it happens, it'll be interesting :D And yes, def go for the bonus, even if your boom is a bit heavier- thats why no boomies this year (that held full weight) were under 7.5 or 8 grams. The bonus makes it very, very competitive.