How to Reduce Tower Weight Without Sacrificing Strength?

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby Balsa Man on Sun May 06, 2012 7:04 pm

As you've seen if you've reviewed this year's tower posts, there are lots of ways to get to a competitive tower, and a range of opinions, both on basic approach and various details. What thsom is suggesting would work. What I suggested would work. They'll both come out in the 15, certainly less than 18gr range. What I suggested will be slightly heavier than what thsom is suggesting; it will also be more tolerant of a less than precise build.

Both should get you an order of magnitude farther along than what you have. Hardwood has no place; there is just no need. There is no need for anything bigger than 1/8th.

The wiki has some good info, also some less than good info; you probably don't have the experience base to tell the difference.

As I said at the outset, time is not your friend. You need to settle on an approach, and then build it as carefully as you can
Len Joeris
Fort Collins, CO
Balsa Man
Coach
Coach
 
Posts: 835
Joined: Thu Nov 13, 2008 7:01 am
Location: Fort Collins, CO
Division: C
State: CO

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby thsom on Sun May 06, 2012 8:33 pm

I agree my design takes a steady hand, however if constructed to plan, you can get away with it being ~10-11 grams, something that could very well win a less competitive state competition and place in the top ten at a very competitive one. Depending on your experience,(seeing the design, I'd say basic) I also agree with a slow CA glue, if you can handle it, i suggest medium CA glue, The only places where I used Thin CA glue was in Joints that I wanted to bond instantly so that they would be exact.
thsom
Member
Member
 
Posts: 194
Joined: Tue Dec 27, 2011 2:26 pm
Division: C
State: IL

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby LKN on Mon May 07, 2012 3:04 am

I'm going to have to go with balsaman with this, you are definitely looking in the neighborhood of 15grams if built reasonably. You are looking at about 1.5grams of base leg weight,3 grams of base bracing, 5ish grams in the chimney legs, and another 4ish grams in bracing the chimney. Tack on wight to attach the chimney and base and inexperience add a gram. You are looking at 15 grams or so at 70cm. Balsa 1/8 varies a lot, but denser stuff for what you want you look at about 2.0-2.4grams per 36" stick and if you pick out stiffer 1/16 balsa you are looking at .5-.6grams per 36" stick. Go the full 70cm centimeters as well, especially following either build design suggested. Find yourself a good blade, I use a window scraper with a razor blade. It makes a good punch-cut action and is quick and convenient. It might take a little bit of muscle to get through 1/8balsa wood, but you should be fine once you get a feel for it.
- LKN
NCSSM '13
User avatar
LKN
Member
Member
 
Posts: 69
Joined: Mon Mar 14, 2011 10:32 pm
Division: C
State: NC

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby Ray Li on Mon May 14, 2012 1:19 am

I am almost finished with my tower. It weighs 13 grams right now, but it will probably be heavier when I glue the base and chimney together. All together, it should weigh around 15 grams. Are there any ways to reduce the weight at this stage? Also what are some good methods to transport towers? I am planning to transport it in two pieces. My team is going by air and I don't think I can take it as a carry on item. I will try and post a picture of the finished tower as soon as possible.
Change is inevitable, except from a vending machine.
User avatar
Ray Li
Member
Member
 
Posts: 16
Joined: Thu May 03, 2012 10:45 pm
Division: C
State: AR

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby J-Fish123 on Mon May 14, 2012 10:52 am

Chicken
J-Fish123
Member
Member
 
Posts: 1
Joined: Wed Jan 11, 2012 11:45 am
Division: B
State: KS

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby Ray Li on Mon May 14, 2012 8:49 pm

Picture of our almost completed tower: http://gallery.scioly.org/data/tmp_medi ... 0561_n.jpg
Change is inevitable, except from a vending machine.
User avatar
Ray Li
Member
Member
 
Posts: 16
Joined: Thu May 03, 2012 10:45 pm
Division: C
State: AR

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby havenguy on Mon May 14, 2012 10:06 pm

Wow, nice. It looks pretty strong and light.
2013: States=S, Nationals

Disease: 3 (S), 16 @ Nats
Forestry: 14 (S), 20 @ Nats
Boomilever: 2 (S) 16 @ Nats
Meteorology: 2 (S) 8 @ Nats
Anatomy: 2 (S), 26 @ Nats

Total medal count (2010-2013): 34
User avatar
havenguy
Member
Member
 
Posts: 420
Joined: Thu Mar 03, 2011 6:06 pm
Division: C
State: PA

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby SLM on Mon May 14, 2012 11:34 pm

Ray Li wrote:Picture of our almost completed tower: http://gallery.scioly.org/data/tmp_medi ... 0561_n.jpg

Nice job!

I don't think you can reduce the weight any further at this point. If you are planning to assemble the tower in Florida, make sure you take a plumb line, a level and some sand paper with you. Before you glue them together, make sure the chimney remains perfectly vertical on top of the base. Otherwise, the tower could easily fail prematurely under the load.
SLM
Member
Member
 
Posts: 195
Joined: Sat Jan 31, 2009 6:24 pm
Division: Grad

Re: How to Reduce Tower Weight Without Sacrificing Strength?

Postby Balsa Man on Sat May 19, 2012 11:33 am

Nice job, indeed.
A VERY long way from where you were. Agree with SLM's advice on putting it together- the key to getting the best out of it.
Good luck!!
Len Joeris
Fort Collins, CO
Balsa Man
Coach
Coach
 
Posts: 835
Joined: Thu Nov 13, 2008 7:01 am
Location: Fort Collins, CO
Division: C
State: CO

Previous

Return to Tower Building

Who is online

Users browsing this forum: No registered users and 1 guest