Chase Krueger
1) I thought that our bridge would carry about 8 kg, because I knew that it could support the weight and it’s own weight. I thought that at at least 2.5 kg there would be no problems and it would begin to flex at around 4 kg and break at double that-- 8kg. I knew that our group definitely did not make the strongest bridge, but I did believe it would not hold as much as it did. Our group had a goal to keep the bridge lightweight and not waste points on heaviness. I believe had a great effort as it actually ended up breaking at 9 kg.
2) I assumed that our bridge would break in the middle. I thought this because that is where we put most of the weight, and the wood grain did not help either. We tried our best to counter the wood grain and form other supports. Our bridge was designed for compression rather than tension which led to it breaking the middle as predicted.
3) My bridge broke at 9 kg.
4) My bridge broke in the middle.
5) My bridge broke because of the lightness of the deck and could not support the weight. It ended up holding 1 kg more than I had anticipated. There was no real reinforcement which led to the failure of our bridge, as explained in question #1.
6) I liked the aesthetics of my bridge as it looked like a clean, regular, and finely-crafted truss bridge between the layout and placement. I also liked how we used the laser cutter as it made it perfectly
7) I disliked how thin the bridge was and it’s appearance looked unsteady. Also, I disliked how it hardly held any weight and broke so quickly! The truss form itself is evidently not the strongest or most logical bridge to build.
8) I thought that several things would be hard about building my bridge including building the truss itself because of the unfavorable wood grain. The problem with that is that the wooden truss grain goes horizontal and had the possibility of buckling under weight as any pressure is applied. Other struggles included weight mounting because the top of the truss was smooth and could allow the weights to slide and apply uneven pressure to parts of the bridge, the weight because although it would be light, it had the potential of being heavy for a truss, and stable mounting because we were unsure if we should glue the bridge to the mount or set it loosely. Also, we were concerned with glueing the deck to the side as supporting it with a low surface area could have been tricky.
9) There were many different aspects of building the bridge, including figuring out how to determine if we should spend more or less money, if we should risk having a heavy weight and a stronger bridge or not, and being strategic with other things like materials. Of all of the things listed in the previous question, those ended up actually being difficult as well. With the thin balsa wood, we were unsure if the bridge would be able to hold the weight. It was extremely hard to build a truss with such thin wood, and we had a hard time determining what would hold a decent amount of weight without blowing our budget or making it outrageously heavy.
10) Something that I would do differently is reversing our idea to keep the bridge light and make it heavy with a lot of reinforcement on the deck. The deck is what made the bridge break under such little weight, because the deck itself was extremely light. If I were to do this experiment over again, I would also not use so much money on laser cutting the bridge, and doing it manually. I would also add a lot more support keeping the pieces together as the glue was clearly not strong enough.
11) Had we made that change, I think the truss bridge would still have broken in the same spot. However, if we had reinforced the deck it would have carried way more weight. But, if we had done that then it would have cost more money with materials and would have cost us with the heavier weight.
Hunter Forcier
1) My initial guess for maximum weight was about 8 Kg, simply because I knew it could support the rig’s weight and its own weight, and I figured under at least 2.5 Kg it wouldn’t have an issue, and it would begin flexing at about 4 Kg, and probably break at about double that, which was 8 Kg. I knew I didn’t make a super strong bridge, so I made it my goal to keep it lightweight and predict its breaking point as close as I could. And I did a pretty decent job, it shattered at 9 Kg.
2) I thought it would break at the middle, and it would lead to a chain reaction breaking from the other supports. I thought this because that’s where we put most of the weight, and the wood grain wasn’t in my favor. I knew about the flaw with the wood grain, and I did my best to counter it. The main issue was that the bridge was designed for compression, and not tension, which is why it broke at the middle, like I predicted.
3) I did like how simple we kept the bridge. We probably made it a little more expensive than we should’ve, but regardless, we made a bridge that was lightweight and easy to assemble. I thought that the hardest part would be reinforcing all the struts and getting them to fit together, and it wasn’t that bad. The hardest part was gluing the decks to the sides, simply because of the low surface area to glue on.
4) My only real regret on this bridge was not continuing to make adjustments to it. I also wish I had added gussets or some sort of reinforcements for the bottom strut connection at the very least. When we finished on Monday, I kept making adjustments until about Wednesday, then I stopped working on it because I was worried about breaking it while it was waiting to be broken, so to speak. I didn’t want to break my bridge and not have enough time to fix it, or not have a bridge at all. If I had made these changes, such as the gussets, I think it would’ve held closer to 20 Kg before a similar breakage would occur, and break at the center.
2) I thought it would break at the middle, and it would lead to a chain reaction breaking from the other supports. I thought this because that’s where we put most of the weight, and the wood grain wasn’t in my favor. I knew about the flaw with the wood grain, and I did my best to counter it. The main issue was that the bridge was designed for compression, and not tension, which is why it broke at the middle, like I predicted.
3) I did like how simple we kept the bridge. We probably made it a little more expensive than we should’ve, but regardless, we made a bridge that was lightweight and easy to assemble. I thought that the hardest part would be reinforcing all the struts and getting them to fit together, and it wasn’t that bad. The hardest part was gluing the decks to the sides, simply because of the low surface area to glue on.
4) My only real regret on this bridge was not continuing to make adjustments to it. I also wish I had added gussets or some sort of reinforcements for the bottom strut connection at the very least. When we finished on Monday, I kept making adjustments until about Wednesday, then I stopped working on it because I was worried about breaking it while it was waiting to be broken, so to speak. I didn’t want to break my bridge and not have enough time to fix it, or not have a bridge at all. If I had made these changes, such as the gussets, I think it would’ve held closer to 20 Kg before a similar breakage would occur, and break at the center.
Ari Benavente