Towers B/C

[GhostPants_]

Yes, X's are glued to the outside of the legs and are slightly bowed and we did glue in the middle of the X.

[Balsa Man]

Yes, X's are glued to the outside of the legs and are slightly bowed and we did glue in the middle of the X.

Thanks

[musicalwhang]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

[MIScioly]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I'm not an expert on towers by any means, but you should definitely be proud of that build, especially being in division B! I think your tower could hold it all probably, but again, I'm not an expert. It looks very well built.

[musicalwhang]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I'm not an expert on towers by any means, but you should definitely be proud of that build, especially being in division B! I think your tower could hold it all probably, but again, I'm not an expert. It looks very well built.

Thank you! I spent a lot of time on this forum and even more building the tower

[Random Human]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I don't exactly know where it would break. Usually when you brace in 1/5 intervals, The buckling will be 10 cm(for div b) each. Your looking at a varied amount of buckling strenth (depending on leg buckling strength). I can't tell where it's gonna break, but 10 cm usually won't cut it. The tower looks nicely constructed, I expect for a high placing. Great Job!

[Random Human]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I don't exactly know where it would break. Usually when you brace in 1/5 intervals, The buckling will be 10 cm(for div b) each. Your looking at a varied amount of buckling strenth (depending on leg buckling strength). I can't tell where it's gonna break, but 10 cm usually won't cut it. The tower looks nicely constructed, I expect for a high placing. Great Job!

Sorry I didn't read where u specified buckling strength to be 28.5 cm. Calculations show, 28.5 cm buckling, at 10 cm won't carry 15, but it looks pretty conservative in terms of weight, so should be getting around 10-12kg in the bucket.

[musicalwhang]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I don't exactly know where it would break. Usually when you brace in 1/5 intervals, The buckling will be 10 cm(for div b) each. Your looking at a varied amount of buckling strenth (depending on leg buckling strength). I can't tell where it's gonna break, but 10 cm usually won't cut it. The tower looks nicely constructed, I expect for a high placing. Great Job!

Just to be on the safe side, I actually built the tower to 52 cms. This made each interval 10.4 cms. Thank you!

[Balsa Man]

Hi all!
States is on Saturday for me and I'm very excited to compete this year. I'm hoping the tower I built for the competition can get a high efficiency.
For the legs, I used 1/8 x 1/8 wood at about 1.2 gr/36". The BS was ~28.5 grams. For my ladders and tension members, I used a combination of .3 gram and .4 gram 1/16 x 1/16 wood. The legs are braced at a 1/5th interval and the lower 3 ladders are lap joints and top 3 are butt joints. Overall, the tower weighs 6.2 grams and I didn't go for the bonus
Attached below are the pics of the tower. I was wondering if anyone had any tips for loading the tower and my possible efficiency. Also, where do you think this tower will break first? Any weaknesses in the design?
Thank you all!
https://drive.google.com/file/d/0ByNusF ... sp=sharing
https://drive.google.com/file/d/0ByNusF ... sp=sharing

I don't exactly know where it would break. Usually when you brace in 1/5 intervals, The buckling will be 10 cm(for div b) each. Your looking at a varied amount of buckling strenth (depending on leg buckling strength). I can't tell where it's gonna break, but 10 cm usually won't cut it. The tower looks nicely constructed, I expect for a high placing. Great Job!

Just to be on the safe side, I actually built the tower to 52 cms. This made each interval 10.4 cms. Thank you!

First, it is a really pretty build; your hard, careful work shows; good precision, good detail.

Based on how the B tower I’ve been working with did at our State tournament last weekend, my guess is failure will be from buckling in the lower ladder (not the sticks right at the base- the ladder 10cm up from the base). Legs were 1.2, 36" BS measured at 37.6gr; 1/4 bracing interval; calculated braced leg strength at 4365gr; 5.9gr tower weight, meeting circle bonus

1/5 interval, ~28.5 BS at 36” should have around 5200gr braced BS w/ ladders and Xs bracing. That’s substantially over design load, suggesting legs should easily be good for carrying full load. However, our important take-away from State was that the assumption that the forces the bracing needs to handle is on the order of 1kg doesn't hold up. Our lower ladders were from 1/8”- 0.91gr/36, 36” BS measured at 20.1gr. One failed/buckled at 9260gr tower load. Still good enough to win, but well below expectation.

When you look at the BS of 1/16 vs 1/8, at the same density, the 1/8 is 16 times that of the 1/16. That’s why my concern/guess that initial failure will be in the lower ladders….. The fact that you're using 1/16 x 1/16 for your Xs (vs the 1/64 x will help- as in they will provide additional bracing against inward buckling of legs toward each other. 1/64th strips provide essentially nothing.

As we all know only too well, actual performance versus calculated performance can be surprising; better or worse. So, hopefully you’re in for a pleasant surprise; pulling for you! Do let us know how it goes.

[musicalwhang]

I don't exactly know where it would break. Usually when you brace in 1/5 intervals, The buckling will be 10 cm(for div b) each. Your looking at a varied amount of buckling strenth (depending on leg buckling strength). I can't tell where it's gonna break, but 10 cm usually won't cut it. The tower looks nicely constructed, I expect for a high placing. Great Job!

Just to be on the safe side, I actually built the tower to 52 cms. This made each interval 10.4 cms. Thank you!

First, it is a really pretty build; your hard, careful work shows; good precision, good detail.

Based on how the B tower I’ve been working with did at our State tournament last weekend, my guess is failure will be from buckling in the lower ladder (not the sticks right at the base- the ladder 10cm up from the base). Legs were 1.2, 36" BS measured at 37.6gr; 1/4 bracing interval; calculated braced leg strength at 4365gr; 5.9gr tower weight, meeting circle bonus

1/5 interval, ~28.5 BS at 36” should have around 5200gr braced BS w/ ladders and Xs bracing. That’s substantially over design load, suggesting legs should easily be good for carrying full load. However, our important take-away from State was that the assumption that the forces the bracing needs to handle is on the order of 1kg doesn't hold up. Our lower ladders were from 1/8”- 0.91gr/36, 36” BS measured at 20.1gr. One failed/buckled at 9260gr tower load. Still good enough to win, but well below expectation.

When you look at the BS of 1/16 vs 1/8, at the same density, the 1/8 is 16 times that of the 1/16. That’s why my concern/guess that initial failure will be in the lower ladders….. The fact that you're using 1/16 x 1/16 for your Xs (vs the 1/64 x will help- as in they will provide additional bracing against inward buckling of legs toward each other. 1/64th strips provide essentially nothing.

As we all know only too well, actual performance versus calculated performance can be surprising; better or worse. So, hopefully you’re in for a pleasant surprise; pulling for you! Do let us know how it goes.

Thank you for your response! So do you think it was the right choice going with 3 butt joints for the top ladders for compression and 3 lap joints for the bottom ladders to serve as tension?