1) May I ask what is the appropriate 3D printer for this project - is this one Ok? Creality Ender 3 Neo 3D Printers with CR Touch Auto Leveling Bed Silent Mainboard Full-Metal Extruder Carborundum Platform DIY Ender 3D Printer for Kids Beginners Printing Size 8.66x8.66x9.84 inch 2) would the layout you shared print tower #5 in your video. Appreciate your help.
Have you done any experiments with grain classification? I'd love to see side-by-side identical mass towers, the difference being B-grain vs C-grain legs
That's a good idea! I might try and do something like that this summer in preparation for next year's tower. I have used C-grain for some of my full tower-builds, and in certain situations for bridges as well. My gut feeling is that is probably is a bit better for compression situations, but it's not a huge difference. It's much more important to get the density/mass where you want it to be. I would only start worrying about it if you are already building extremely competitive towers (< ~5g for Div C, < ~4.7g for Div B) and are looking for that last tiny advantage. If your towers are well above that, don't bother with the extra expense of C-grain
Hi! I highly recommend you buy your balsa in sheets (which are usually 36" long) and cut your own strips to any length and width you want. I like to use Specialized Balsa, but you can get balsa sheets many places. Check out this video when you get a chance: th-cam.com/video/bLsTOpmozGI/w-d-xo.html
If it were based on the 2018 rules, it seems impossible to make the tower legs a straight piece because of the circle and the height rules (Div C) How would you approach it?
You are correct! This basic design would have only worked for the 2017 rules. The 2018 rules required basically a 2-part design with a large base with a tall, narrow column on top of that. It was quite complex to build that year! It'll be interesting to see what design specifications they have for this year. FWIW, the concepts shown here regarding buckling and bracing design definitely applied even for the 2018 rules, but it was implemented in 2 different parts for the final tower
Hello! thank you for making these informative and detailed videos. I was wondering, what CAD software do you use to make your jig? I have been using tinkercad, but it has not been precise enough for making a jig. Thanks in advance!
Hi! Thanks for the kind feedback! I've been using Solidworks for my modeling. It's a really nice tool and worthwhile to learn if you have access to it, but it's not free. You might want to check out FreeCAD which seems like it would have the features to make good jigs. BTW, I will be releasing the STL files I'm using for my actual builds for this season once the rules come out, so you'll be able to get started with that if you want.
Hello, I have two questions. First off, do you know around the time the draft rules for the 23-24 season come out, and should the legs be stripped from one piece of wood or should they be precut? Since you talked about how to have the best tower, they should be the same weight.
I think the draft rules typically come out in mid-July. That is the time of the Science Olympiad coaching seminar. I always strip my balsa pieces. It's not too difficult and much cheaper than buying pre-cut pieces. Either way, you will have to have a large library of pieces to get identical ones to choose from, but it's worth it. I go over some of the challenges of getting the exact pieces you want in this video: th-cam.com/video/bLsTOpmozGI/w-d-xo.html
@@longjay69 I've never tried that as I don't have access to a good laser cutter, but my guess is that for simple stripping of sheets, it won't be worth the hassle. If you try it, please let me know how it goes!
We played around with 3-legged towers back in 2016. It wasn't worth the hassle for the most part. The angles for the cross-bracing are difficult to make work as nicely as a 4-legged towers. Feel free to experiment though! It might depend on the actual rules if it makes sense or not.
Howdy, what materials could we use to make our on jig without 3D printing? Also, is an octogon a better base than a square, and what is the optimal amount of cross members? Lastly, I haven't seen the rules yet, are they out? Thank you so much.
I coached Towers in 2017 before I had a 3D printer and we made an assembly jig out of wood and copper pipe. Imagine a 4x4 block with a 1/2" hole drilled in it. That block is glued to a piece of wood and a copper tube is in the hole. Then at the correct height, you make a top that holds the 4 legs in place. With a jig like that, you build 2 sides flat first and then put them in place on the jig and connect the rest. That can work well if you are careful. A square is the simplest design as you don't need to worry about angling the cross-pieces. An octagon might be fun to play around with, but I'd wait until you have some simpler towers made first. From my tower study, something like 5-7cm gap is a good starting point for the # of layers. The official rules don't come up until early September. The draft rules are available via the SciOly summer workshop, but they aren't published publicly
@@AabirKhan-n8h The mini-towers were 25cm tall. I'd say the mass scales fairly linearly with the height and retains most of the strength, so the ~7400 efficiency 25cm tower is very much like a 3700 efficiency 50cm tower
Has there been any advantage to braces across the centre to prevent the rhombic buckling mode or did you find it a waste of weight and getting in the way of the central chain?
@@TimpBizkit Yeah, cross bracing completely across the center wouldn't work as there needs to be room for the chain. While these structures can deform easily in that mode, it doesn't seem to effect the strength vertically
Would you think it would be ideal to scale up your jig to normal tower size? Also, whats the benefit of a pyramid shaped tower, versus one that has a pyramid shape on the bottom with a rectangular prism on top?
Hi! While I don't know the final rules for the upcoming season yet, I would guess scaling something like this up to full size will work well. It certainly did with the 2017 rules. As for a continuous versus a 2-part prism, I'm a big fan of keeping things as simple as possible. Usually continuous pieces are a much better solution than a piecewise solution. FWIW, the 2018 rules pretty much required a 2-part solution and it was very complex to build. I'd probably recommend at least starting with the simpler design first and then experimenting once you know what kind of scores you'll need to beat with a more complex design
@@rylanchau3645 Unfortunately, I don't. Back in 2017, I didn't have a 3D printer yet, so we built the assembly jigs out of copper pipe and wood. I am currently working on some preliminary builds with the draft rules. I will definitely have something to share when the new season officially starts
what size balsa for the legs?
I like to use 1/8" x 1/8" for the legs. I recommend you try that as a good starting point
1) May I ask what is the appropriate 3D printer for this project - is this one Ok? Creality Ender 3 Neo 3D Printers with CR Touch Auto Leveling Bed Silent Mainboard Full-Metal Extruder Carborundum Platform DIY Ender 3D Printer for Kids Beginners Printing Size 8.66x8.66x9.84 inch 2) would the layout you shared print tower #5 in your video. Appreciate your help.
That 3D printer should do fine, especially with the non-bonus jig which is what I'd recommend you start with. Good luck!
Have you done any experiments with grain classification? I'd love to see side-by-side identical mass towers, the difference being B-grain vs C-grain legs
That's a good idea! I might try and do something like that this summer in preparation for next year's tower. I have used C-grain for some of my full tower-builds, and in certain situations for bridges as well. My gut feeling is that is probably is a bit better for compression situations, but it's not a huge difference. It's much more important to get the density/mass where you want it to be. I would only start worrying about it if you are already building extremely competitive towers (< ~5g for Div C, < ~4.7g for Div B) and are looking for that last tiny advantage. If your towers are well above that, don't bother with the extra expense of C-grain
Hello, Thank you for the video. Any idea where to buy the Balsa wood that is 22 inches (>50cm) or longer? Thank you
Hi! I highly recommend you buy your balsa in sheets (which are usually 36" long) and cut your own strips to any length and width you want. I like to use Specialized Balsa, but you can get balsa sheets many places. Check out this video when you get a chance: th-cam.com/video/bLsTOpmozGI/w-d-xo.html
If it were based on the 2018 rules, it seems impossible to make the tower legs a straight piece because of the circle and the height rules (Div C) How would you approach it?
You are correct! This basic design would have only worked for the 2017 rules. The 2018 rules required basically a 2-part design with a large base with a tall, narrow column on top of that. It was quite complex to build that year! It'll be interesting to see what design specifications they have for this year. FWIW, the concepts shown here regarding buckling and bracing design definitely applied even for the 2018 rules, but it was implemented in 2 different parts for the final tower
Hello! thank you for making these informative and detailed videos. I was wondering, what CAD software do you use to make your jig? I have been using tinkercad, but it has not been precise enough for making a jig. Thanks in advance!
Hi! Thanks for the kind feedback! I've been using Solidworks for my modeling. It's a really nice tool and worthwhile to learn if you have access to it, but it's not free. You might want to check out FreeCAD which seems like it would have the features to make good jigs. BTW, I will be releasing the STL files I'm using for my actual builds for this season once the rules come out, so you'll be able to get started with that if you want.
Thank you!
Hello, I have two questions. First off, do you know around the time the draft rules for the 23-24 season come out, and should the legs be stripped from one piece of wood or should they be precut? Since you talked about how to have the best tower, they should be the same weight.
I think the draft rules typically come out in mid-July. That is the time of the Science Olympiad coaching seminar. I always strip my balsa pieces. It's not too difficult and much cheaper than buying pre-cut pieces. Either way, you will have to have a large library of pieces to get identical ones to choose from, but it's worth it. I go over some of the challenges of getting the exact pieces you want in this video: th-cam.com/video/bLsTOpmozGI/w-d-xo.html
Any thoughts on laser cutting a sheet of balsa vs stripping it? Can you see any disadvantages or pitfalls of laser cutting?
@@longjay69 I've never tried that as I don't have access to a good laser cutter, but my guess is that for simple stripping of sheets, it won't be worth the hassle. If you try it, please let me know how it goes!
Is building a tower with only 3 legs a good idea?
We played around with 3-legged towers back in 2016. It wasn't worth the hassle for the most part. The angles for the cross-bracing are difficult to make work as nicely as a 4-legged towers. Feel free to experiment though! It might depend on the actual rules if it makes sense or not.
Howdy, what materials could we use to make our on jig without 3D printing? Also, is an octogon a better base than a square, and what is the optimal amount of cross members? Lastly, I haven't seen the rules yet, are they out? Thank you so much.
Also how tall did you make these mini towers, and will we get similar efficiency if we have proportional cross member spacing?
I coached Towers in 2017 before I had a 3D printer and we made an assembly jig out of wood and copper pipe. Imagine a 4x4 block with a 1/2" hole drilled in it. That block is glued to a piece of wood and a copper tube is in the hole. Then at the correct height, you make a top that holds the 4 legs in place. With a jig like that, you build 2 sides flat first and then put them in place on the jig and connect the rest. That can work well if you are careful. A square is the simplest design as you don't need to worry about angling the cross-pieces. An octagon might be fun to play around with, but I'd wait until you have some simpler towers made first. From my tower study, something like 5-7cm gap is a good starting point for the # of layers. The official rules don't come up until early September. The draft rules are available via the SciOly summer workshop, but they aren't published publicly
@@AabirKhan-n8h The mini-towers were 25cm tall. I'd say the mass scales fairly linearly with the height and retains most of the strength, so the ~7400 efficiency 25cm tower is very much like a 3700 efficiency 50cm tower
@@balsaengineering6686 Thank you so much. My school is starting up science olympiad so I am excited.
Hello, i was wondering if there was any way to get 1/32 balsa sticks from flat sheets. Or if you would recommend buying them pre cut.
It's possible to use a balsa stripper to cut sticks from a 1/32" sheet, that's what I do, but it's challenging, so it does take some practice.
@@balsaengineering6686 if we were on a time crunch would u say its fine to use 3/32 X 3/32 as a replacement for the 1/32 cross braces
Has there been any advantage to braces across the centre to prevent the rhombic buckling mode or did you find it a waste of weight and getting in the way of the central chain?
@@TimpBizkit Yeah, cross bracing completely across the center wouldn't work as there needs to be room for the chain. While these structures can deform easily in that mode, it doesn't seem to effect the strength vertically
Would you think it would be ideal to scale up your jig to normal tower size? Also, whats the benefit of a pyramid shaped tower, versus one that has a pyramid shape on the bottom with a rectangular prism on top?
Hi! While I don't know the final rules for the upcoming season yet, I would guess scaling something like this up to full size will work well. It certainly did with the 2017 rules. As for a continuous versus a 2-part prism, I'm a big fan of keeping things as simple as possible. Usually continuous pieces are a much better solution than a piecewise solution. FWIW, the 2018 rules pretty much required a 2-part solution and it was very complex to build. I'd probably recommend at least starting with the simpler design first and then experimenting once you know what kind of scores you'll need to beat with a more complex design
@@balsaengineering6686 do you have a scaled up stl from 2017 rules?
@@rylanchau3645 Unfortunately, I don't. Back in 2017, I didn't have a 3D printer yet, so we built the assembly jigs out of copper pipe and wood. I am currently working on some preliminary builds with the draft rules. I will definitely have something to share when the new season officially starts
@@balsaengineering6686 oh alr thank you so much!