Bridge B/C

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0ddrenaline
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Re: Bridge B/C

Post by 0ddrenaline »

mklinger wrote: October 27th, 2021, 9:18 am Quick informal survey, would people have any interest in me creating a long-form video where I record myself building my latest Div C bridge design and talking through the build process? I could show the glue techniques I'm using as well as more of the general process rather than just the final result.

Thanks!

Marc
That would be helpful! A long form video would answer some questions about details that weren't addressed in other videos. One simple thing I was impressed by was the spreadsheet in your introduction video. I don't think my teams have ever been that organized with keeping track of their progress and design choices. A video on this topic might be good if you're taking suggestions. I'll definitely show your videos to my students and make sure we use the information in practice :D
Tall
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Re: Bridge B/C

Post by Tall »

mklinger wrote: October 27th, 2021, 9:18 am Quick informal survey, would people have any interest in me creating a long-form video where I record myself building my latest Div C bridge design and talking through the build process? I could show the glue techniques I'm using as well as more of the general process rather than just the final result.

Thanks!

Marc
Absolutely, it will help. Thanks.
mklinger
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Re: Bridge B/C

Post by mklinger »

0ddrenaline wrote: October 27th, 2021, 10:56 am
mklinger wrote: October 27th, 2021, 9:18 am Quick informal survey, would people have any interest in me creating a long-form video where I record myself building my latest Div C bridge design and talking through the build process? I could show the glue techniques I'm using as well as more of the general process rather than just the final result.

Thanks!

Marc
That would be helpful! A long form video would answer some questions about details that weren't addressed in other videos. One simple thing I was impressed by was the spreadsheet in your introduction video. I don't think my teams have ever been that organized with keeping track of their progress and design choices. A video on this topic might be good if you're taking suggestions. I'll definitely show your videos to my students and make sure we use the information in practice :D
Thanks! Yeah, a spreadsheet can be incredibly handy especially when you have the design nailed down and are to the material optimization part. It's also more important the more people are involved. This year, with no students and just me, I've been using a standard notebook to record my builds as my design has been changing a lot so far. I had originally thought about doing a couple retrospective videos on exactly how we as a team evolved for the various historic events (bridges of past, towers, boomis, etc). That would definitely feature our old spreadsheets and design tracking. I may still do that, but I wanted to first provide what I think is more direct useful info for this year's teams.

The biggest tip I can provide to help a team of students become more organized would be to provide them with a blank form on paper, basically a blank spreadsheet page, where they then fill in the specifics for every build as they build it. You can then transfer the data to a real spreadsheet to capture data from all the students. That's what I typically did.

Have them think in terms of not just component starting mass, but mass budgets for each module of the build. For example, with this year's bridge, I like to weigh the completed sides before final assembly. For something like the boomi, we kept track of the tension component completely separately from the base. This would be a good way to see if someone is using too much glue, or if something isn't right, when two students who are using the same pieces with the same mass have different module weights. It also gets the students in the habit of weighing everything and knowing exactly what is in their device.

If you know you have good results with a certain cross member design for example and are considering changing it, you need to make it lighter to make it worthwhile. That's why we tried to weigh everything as we built it. Say, the "X" members for the boomi base. Cut all the pieces and weigh them all. That is your mass budget for base cross members. If you want to try a different dimension/density/#, you cut up what you want to try and see if it's less. If not, it's not worth trying. You get to the point in the process where you can pre-pick your wood and very accurately predict the final device weight. This is especially handy near important competitions. Last year, we could pick out all the material ahead of time before cutting anything and predict the final mass within about 0.2g.

Another fun thing we did as a team throughout the years was have a friendly internal competition. We'd have a "Top 10" scores posted for all the students (and I also had a coach's Top 10 they could compete with).

A big part of this whole process is knowing what scores are possible, with any design, and what scores are possible with your current design. If you have a design that isn't progressing towards what is possible with a different design, it's time to change your design. This is usually done by watching good teams at invitationals and whenever teams share scores on the forums, etc.

Hopefully, some of what my videos show is giving teams a jump-start on seeing what is possible. I hate seeing people come to competitions with really bad designs that they've obviously spent a lot of time on!
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Re: Bridge B/C

Post by coachchuckaahs »

This is a very important aspect in ANY build with optimization, especially weight. You cannot know how much GLUE adds weight to a structure!

It is also one of the hardest things to teach. Especially if you do not start logging from the first stick cut and first glue joint. It is EASY to get lazy and stop recording. It is easy to forget to write down the mass even if weighed! I tell my flying students that if they did not write it down, you did not do it!

Having a structured spreadsheet to record item masses and cumulative module mass (as you add each item, to get the glue mass) is a very good way to capture the progress. Most importantly, when a plane is overweight, we peruse these sheets, and either compare to a budget, or compare to prior builds (mine and students) to figure out what step got us over budget. On the super light planes (F1D, 1.4g for 55cm wingspan), one cannot improve without this data!

In Bridges, you will build far more structures than we do in planes, and having records like this are critical. In addition to mass, we record the source (we serial number our sheets), the density (pounds per cu ft), and grain (A, B, C). Even that is sometimes not enough, as the density and flexural stiffness can vary considerably across the sheet.

Coach Chuck
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sciolyperson1 (October 27th, 2021, 6:15 pm)
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Re: Bridge B/C

Post by drcubbin »

0ddrenaline wrote: October 27th, 2021, 10:56 am
mklinger wrote: October 27th, 2021, 9:18 am Quick informal survey, would people have any interest in me creating a long-form video where I record myself building my latest Div C bridge design and talking through the build process? I could show the glue techniques I'm using as well as more of the general process rather than just the final result.

Thanks!

Marc
That would be helpful! A long form video would answer some questions about details that weren't addressed in other videos. One simple thing I was impressed by was the spreadsheet in your introduction video. I don't think my teams have ever been that organized with keeping track of their progress and design choices. A video on this topic might be good if you're taking suggestions. I'll definitely show your videos to my students and make sure we use the information in practice :D
If you did that, I would put you on my Christmas list :) Thank you in advance!!
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Re: Bridge B/C

Post by GeorgeT »

Does anyone know a good bridge design? (Apart from the gallery designs.)
Thank you,
George
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Re: Bridge B/C

Post by mklinger »

drcubbin wrote: October 29th, 2021, 7:10 am
0ddrenaline wrote: October 27th, 2021, 10:56 am
mklinger wrote: October 27th, 2021, 9:18 am Quick informal survey, would people have any interest in me creating a long-form video where I record myself building my latest Div C bridge design and talking through the build process? I could show the glue techniques I'm using as well as more of the general process rather than just the final result.

Thanks!

Marc
That would be helpful! A long form video would answer some questions about details that weren't addressed in other videos. One simple thing I was impressed by was the spreadsheet in your introduction video. I don't think my teams have ever been that organized with keeping track of their progress and design choices. A video on this topic might be good if you're taking suggestions. I'll definitely show your videos to my students and make sure we use the information in practice :D
If you did that, I would put you on my Christmas list :) Thank you in advance!!
Thanks! I think I'm going to separate out the general glue and glue techniques into a separate video and do that one first. So keep an eye out for that soon. This will be my first attempt at a "live" video with no script, so we'll see how it goes :)
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drcubbin (October 30th, 2021, 3:49 am)
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Re: Bridge B/C

Post by mklinger »

Here is my long-form gluing techniques video:

https://youtu.be/55lb2KzSiwg

This was unscripted, so I apologized for any ramblings. Let me know if you like this kind of thing. I hope to make one covering an entire new build of my Div C bridge design soon.

Feel free to let me know if you have any specific suggestions on topics or videos you'd like to see.

Thanks!!

Marc
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sciolyperson1 (October 30th, 2021, 2:49 pm)
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Re: Bridge B/C

Post by mklinger »

In the complete opposite of a "YouTube Short", I have created a 75 minute video which shows the complete process of building my latest Division C design from start to finish. I also talk a bit about how and what I record for the builds and how to use the data from a previous build to optimize a new one.

I didn't edit this too much as I wanted to relay the feel for how long you have to hold each joint, etc. But I won't be offended if you watch this at faster than 1x playback speed :)

https://youtu.be/7W839KEcKes

Let me know if you like this kind of thing and if you have any questions.

Thanks!

Marc
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sciolyperson1 (November 2nd, 2021, 8:35 am)
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Re: Bridge B/C

Post by mklinger »

This is the bridge I featured during my hour+ long "full-build" video. Check that out if you are interested in seeing exactly how this was built and what materials were used.

The final results were 9.53 g holding 19.54 kg for a competition score of 2098.6!

I'm pretty happy with those results and I think this Division C bridge is at least on par with my best Division B result to date.

https://youtu.be/OIs0VZt0xiY

Good luck to everyone building this season!

Let me know if you have any questions or have any suggestions for future video topics.

Thanks!

Marc
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sciolyperson1 (November 3rd, 2021, 5:22 pm) • GeorgeT (November 4th, 2021, 12:10 pm)
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