You are, I think, far too young to remember the TV programe the Great Egg Race, with Heinz Wolff et al presenting - it was in the 70's/80's when TV had 4 channels and other than that you went to the movies, so it was quite popular. They did a variety of challenges, many involving eggs, I particularly remember the egg used as the weight on the end of a string that swung around a pole to create a primitive escapement in the 'create a clock' challenge. They would have been proud of you, though TIG welding would have seen as a bit too space age I think.
Actually I am old enough to remember the Great Egg Race, though only just! I can only really recall one episode where they had to build machines that walked down a slope carrying an egg. All they had to build it with was balsa wood and string, and they only had 2 hours!
I did think about being creative with the dimensions, there is plenty of space left over widthwise. But I didn't want to fall foul of the rules in case they just measured it front to back only.
@@AndysMachines when I was in high school we had a softball throw competition the winner fit inside the 3x3x3ft cube corner to corner They threw the soft ball out of the track field and disappear over a hill
Andy, have you considered making the weighted arm shorter? Perhaps 50% of its current length? it's the same amount of PE, but the centre of mass is approximately in the centre of the body and should therefore reduce tipping. The reduction in torque can already be overcome with your cam/leverage arrangement. Overall, I like your 'folded' design. It's an elegant solution to a tricky problem! Also you should enter the competition anyway. I think you're underestimating yourself here. Good luck!
I did play around with the relative lengths of the arms and the gearing, and planned to do more of this but eventually abandoned this design. I have entered the competition, but with the trebuchet you'll see in the next video (only one entry per person is allowed)
Can't wait to see the next spring-loaded mechanism! For anyone who wants to see the other quirky egg-throwing machines in action, the Fieldhouse Egg-a-pult event is to be live-streamed on UA-cam on Saturday 1st July at 10:00.
@@AndysMachines Hi Andy, yes I am, but only indirectly this time, as I have been working with colleagues to encourage them to get involved. Four machines are being entered from our Epsom office, and I think you will find them particularly interesting, given your technical know-how (they are definitely not conventional). Thanks for your video by the way, and for the brilliant introduction to the problem; what you have shown is the hard work and experimentation that lies behind each entry - something that is often overlooked when the final polished version is tested on the day. I'm very much looking forward to your next video.
Wow! I've seen a couple of the other entries already (on Facebook) and it looks like there's going to be some serious competition, I'm really not confident of my chances! I have to say, in the previous challenges, the winner has usually come up with an ingenious design that probably wouldn't have occurred to me. I'm looking forward to seeing some other unconventional solutions.
This is clearly an exercise in thinking out of the box, many trials and errors. Half the fun of this is the journey, not the destination. I'll be waiting to see what you come up with, and how you work the problem into a working solution.
Yes, It's definitely a journey! I'm not confident I'll actually win, there may be be a different design of trebuchet I'm unaware of that's just better. But I think my entry might have the most development behind it!
I have seen all sorts of challenges like this and almost all of them are not interesting, because we (engineers) already know the answer, this is not that simple. You did an awesome job of actually defining the scope of the problem, so we have an obvious best case. I would be interested to see what an actual trebuchet, built within the specified limitations, to established engineering standards could achieve, as a baseline to compare to. You didn't say this in your video, but it is worth saying, a trebuchet is a gravity amplifier. It takes a slow acting but powerful force, gravity, and amplifies it to throw an object faster than gravity alone can affect the object. As a result the object can defy gravity for a short time, and thus be thrown a distance. Also, there is always the equal but opposite force to worry about. A classic trebuchet design is massive. As a result you get a significant dampening of resultant forces. You saw that, when you added a bunch of weight that dampened out reactive forces, it worked better. Given the rules, I suspect (finger in the air, rough guess) that conversion into pneumatic force is the way to go. A big cylinder compressed by a weight going to a small bore with a mechanism to release all the pressure at once.
Yes, it sounds simple, but it's actually quite a challenge to build a trebuchet within the size and weight limits. I did toy with the idea of building an exact replica scaled down wooden trebuchet to use as a comparison, I don't expect the range would have been more than 2-3 metres when firing an egg. I would really like to see a pneumatic cannon, perhaps somebody else might have even built one.
I'm excited for part 2. I like the idea of using pulleys to flip the weight around, but I wonder what the results would be like if you tested the weights and arm lengths using the traditional design, even though they would violate the rules.
Well at the end of the next video you will see there are leaves on the trees, whereas in this video there are still last autumn's leaves on the ground! It was around 3 months from start to finish, but I'm always working on several projects at the same time so it was worked in around other things.
Mark Rober did an egg drop from the stratosphere and shrouded it in a football to help it land intact, I think shrouding it in a chicken is a lot more fun. Surely the chicken wouldn’t be counted as part of the machine weight. Intrigued to see what the spring does for the design, I was thinking if you had a two stoke effect, split the weights trigger releases the first weight which swings to the front to weight it down but gets the main weight off to a jerked start, could you get more momentum into the rig and thus more force behind the projectile while making use of the counterweight
Here I was going to suggest an osmium counterweight to maximize the moment arm, but that jazz runs about €1200 per _gram_ so you might have to settle for something cheaper like gold. That or tungsten, it's about €130 per kilo and available in pellets.
Well I did consider using brass instead of steel as it's slightly denser, but I think there are a lot of other things to optimise before the material the counterweight is made of becomes a significant problem.
True. Due to air resistance it's always slightly less than 45°. But at this short range and low speed, plus with the whole setup not being very repeatable, somewhere 45°ish is the best I could hope for.
Great video, looking forward to Part 2. My two thoughts watching this: 1) to improve the trebuchet design could consider adding some very light materials to the front, to fluff out and create air resistance to anchor the front down and reduce that rebound effect. Mass isn’t the only thing that can resist momentum, drag can too ;-) 2) could possibly make and air gun design. Egg loaded in a barrel, falling weight onto a bladder creates a blast of air propelling the egg. I have my doubts it would be a net performance increase but it’s a curious idea at least. As I was typing I came up with a third: since the apparatus is allowed to move when released, might be a cheeky way to get around it by letting it roll really far forwards. Why throw an egg when you can make an egg-mobile instead? Haha. Maybe the rules don’t allow that amount of cheese though lol
Some great ideas! I didn't really think about using air resistance in this way, though I was aware that the pouch holding the egg can cause a lot of drag if it's too big. The air bag idea was actually used as a suggestion on the competition poster. I have doubts about it's efficiency too, but it would be interesting to see, and also easy to aim for the correct trajectory. Yes, I'm wondering if somebody will use a rolling technique, though there is a clause in the rules that states if any part of the machine goes further than the egg then the distance will be counted as zero.
@@AndysMachines oh that phrasing is catnip to me. I’d have a gravity powered cart for sure, with an egg glued on the front like a friggin unicorn. Technically not quite cheating; the best form of compliance there is hahaha
@@AndysMachines the air resistance idea came from a memory of that science demonstration where a ruler off the edge of a table with a piece of paper can catch a falling hammer or whatever.
It's not really a trebuchet it's more of a catapult. On a trebuchet the weight swings through rather than dropping to the ground which stops the violent jump back/up of the chassis. That said I still enjoyed the video and am looking forward to part 2
Apparently, all trebuchets are catapults, but not all catapults are trebuchets. As I understand it (or at least as I think of it), trebuchets use a counterweight whereas catapults use some form of spring (springy wood, twisted rope, elastic etc...) I don't think there's a hard and fast definition. There is actually a type of trebuchet called a 'floating beam trebuchet' where the weight falls or slides directly downwards. I think the main reason my trebuchet jumps backwards is because the frame is very light relative to the counterweight and even the projectile, of course real siege trebuchets are much more massive.
Yes, nice idea, but it would only be allowed to be stored as gravitational potential energy, and the height/weight limits would still apply so I don't see how you could store extra energy. Using the extra height from table to floor would be the way to get a real advantage, only 2 people attempted this (and one of those was one of the organisers).
You are, I think, far too young to remember the TV programe the Great Egg Race, with Heinz Wolff et al presenting - it was in the 70's/80's when TV had 4 channels and other than that you went to the movies, so it was quite popular. They did a variety of challenges, many involving eggs, I particularly remember the egg used as the weight on the end of a string that swung around a pole to create a primitive escapement in the 'create a clock' challenge. They would have been proud of you, though TIG welding would have seen as a bit too space age I think.
Actually I am old enough to remember the Great Egg Race, though only just! I can only really recall one episode where they had to build machines that walked down a slope carrying an egg. All they had to build it with was balsa wood and string, and they only had 2 hours!
I love your videos so very much. Your sense of humor and your brilliant engineering are unmatched.
Stanton had a great series about optimizing a trebuchet. Also appreciated his attempt at a flywheel to capture the falling weight's energy.
I did actually watch those, but not until after I'd already decided on my plan of action, otherwise I might have done things slightly differently.
Start over put the trebusha corner to corner to make more room for a longer arm
I did think about being creative with the dimensions, there is plenty of space left over widthwise. But I didn't want to fall foul of the rules in case they just measured it front to back only.
@@AndysMachines when I was in high school we had a softball throw competition the winner fit inside the 3x3x3ft cube corner to corner
They threw the soft ball out of the track field and disappear over a hill
Andy, have you considered making the weighted arm shorter? Perhaps 50% of its current length? it's the same amount of PE, but the centre of mass is approximately in the centre of the body and should therefore reduce tipping. The reduction in torque can already be overcome with your cam/leverage arrangement. Overall, I like your 'folded' design. It's an elegant solution to a tricky problem! Also you should enter the competition anyway. I think you're underestimating yourself here. Good luck!
I did play around with the relative lengths of the arms and the gearing, and planned to do more of this but eventually abandoned this design. I have entered the competition, but with the trebuchet you'll see in the next video (only one entry per person is allowed)
Can't wait to see the next spring-loaded mechanism! For anyone who wants to see the other quirky egg-throwing machines in action, the Fieldhouse Egg-a-pult event is to be live-streamed on UA-cam on Saturday 1st July at 10:00.
Are you entering this one, Simon?
@@AndysMachines Hi Andy, yes I am, but only indirectly this time, as I have been working with colleagues to encourage them to get involved. Four machines are being entered from our Epsom office, and I think you will find them particularly interesting, given your technical know-how (they are definitely not conventional). Thanks for your video by the way, and for the brilliant introduction to the problem; what you have shown is the hard work and experimentation that lies behind each entry - something that is often overlooked when the final polished version is tested on the day. I'm very much looking forward to your next video.
Wow! I've seen a couple of the other entries already (on Facebook) and it looks like there's going to be some serious competition, I'm really not confident of my chances!
I have to say, in the previous challenges, the winner has usually come up with an ingenious design that probably wouldn't have occurred to me. I'm looking forward to seeing some other unconventional solutions.
This is clearly an exercise in thinking out of the box, many trials and errors. Half the fun of this is the journey, not the destination. I'll be waiting to see what you come up with, and how you work the problem into a working solution.
Yes, It's definitely a journey! I'm not confident I'll actually win, there may be be a different design of trebuchet I'm unaware of that's just better. But I think my entry might have the most development behind it!
I have seen all sorts of challenges like this and almost all of them are not interesting, because we (engineers) already know the answer, this is not that simple. You did an awesome job of actually defining the scope of the problem, so we have an obvious best case.
I would be interested to see what an actual trebuchet, built within the specified limitations, to established engineering standards could achieve, as a baseline to compare to.
You didn't say this in your video, but it is worth saying, a trebuchet is a gravity amplifier. It takes a slow acting but powerful force, gravity, and amplifies it to throw an object faster than gravity alone can affect the object. As a result the object can defy gravity for a short time, and thus be thrown a distance.
Also, there is always the equal but opposite force to worry about. A classic trebuchet design is massive. As a result you get a significant dampening of resultant forces. You saw that, when you added a bunch of weight that dampened out reactive forces, it worked better.
Given the rules, I suspect (finger in the air, rough guess) that conversion into pneumatic force is the way to go. A big cylinder compressed by a weight going to a small bore with a mechanism to release all the pressure at once.
Yes, it sounds simple, but it's actually quite a challenge to build a trebuchet within the size and weight limits. I did toy with the idea of building an exact replica scaled down wooden trebuchet to use as a comparison, I don't expect the range would have been more than 2-3 metres when firing an egg.
I would really like to see a pneumatic cannon, perhaps somebody else might have even built one.
Very cool challenge and a wonderful attempt! :)
I'm excited for part 2. I like the idea of using pulleys to flip the weight around, but I wonder what the results would be like if you tested the weights and arm lengths using the traditional design, even though they would violate the rules.
Great video. You must be the most inventive and creative engineer on UA-cam. How long did it take to produce all these prototypes?
Well at the end of the next video you will see there are leaves on the trees, whereas in this video there are still last autumn's leaves on the ground!
It was around 3 months from start to finish, but I'm always working on several projects at the same time so it was worked in around other things.
Andy, catapult the chicken, they will flap the wings and gain a few meters and lay an egg in the excitement
Interesting idea! How much does a live chicken weigh?
Mark Rober did an egg drop from the stratosphere and shrouded it in a football to help it land intact, I think shrouding it in a chicken is a lot more fun. Surely the chicken wouldn’t be counted as part of the machine weight. Intrigued to see what the spring does for the design, I was thinking if you had a two stoke effect, split the weights trigger releases the first weight which swings to the front to weight it down but gets the main weight off to a jerked start, could you get more momentum into the rig and thus more force behind the projectile while making use of the counterweight
Here I was going to suggest an osmium counterweight to maximize the moment arm, but that jazz runs about €1200 per _gram_ so you might have to settle for something cheaper like gold. That or tungsten, it's about €130 per kilo and available in pellets.
Well I did consider using brass instead of steel as it's slightly denser, but I think there are a lot of other things to optimise before the material the counterweight is made of becomes a significant problem.
Optimum angle is NOT 45 degrees. That depends on the aerodynamic properties of the egg and elevation aka air density. More precisely a schnitzel less.
True. Due to air resistance it's always slightly less than 45°. But at this short range and low speed, plus with the whole setup not being very repeatable, somewhere 45°ish is the best I could hope for.
This potato weighs the same as an egg.
what an egg-citing development
Eggcatley
Each entry for the competition has to have a name, want to guess what I called mine?
@@AndysMachines obviously the T-EGG1000
You're thinking along the right lines!
@@AndysMachines LOL then it must be the mother clucker?
Great video, looking forward to Part 2.
My two thoughts watching this:
1) to improve the trebuchet design could consider adding some very light materials to the front, to fluff out and create air resistance to anchor the front down and reduce that rebound effect. Mass isn’t the only thing that can resist momentum, drag can too ;-)
2) could possibly make and air gun design. Egg loaded in a barrel, falling weight onto a bladder creates a blast of air propelling the egg. I have my doubts it would be a net performance increase but it’s a curious idea at least.
As I was typing I came up with a third: since the apparatus is allowed to move when released, might be a cheeky way to get around it by letting it roll really far forwards. Why throw an egg when you can make an egg-mobile instead? Haha. Maybe the rules don’t allow that amount of cheese though lol
Some great ideas!
I didn't really think about using air resistance in this way, though I was aware that the pouch holding the egg can cause a lot of drag if it's too big.
The air bag idea was actually used as a suggestion on the competition poster. I have doubts about it's efficiency too, but it would be interesting to see, and also easy to aim for the correct trajectory.
Yes, I'm wondering if somebody will use a rolling technique, though there is a clause in the rules that states if any part of the machine goes further than the egg then the distance will be counted as zero.
@@AndysMachines oh that phrasing is catnip to me. I’d have a gravity powered cart for sure, with an egg glued on the front like a friggin unicorn. Technically not quite cheating; the best form of compliance there is hahaha
@@AndysMachines the air resistance idea came from a memory of that science demonstration where a ruler off the edge of a table with a piece of paper can catch a falling hammer or whatever.
It's not really a trebuchet it's more of a catapult. On a trebuchet the weight swings through rather than dropping to the ground which stops the violent jump back/up of the chassis. That said I still enjoyed the video and am looking forward to part 2
Apparently, all trebuchets are catapults, but not all catapults are trebuchets. As I understand it (or at least as I think of it), trebuchets use a counterweight whereas catapults use some form of spring (springy wood, twisted rope, elastic etc...) I don't think there's a hard and fast definition.
There is actually a type of trebuchet called a 'floating beam trebuchet' where the weight falls or slides directly downwards. I think the main reason my trebuchet jumps backwards is because the frame is very light relative to the counterweight and even the projectile, of course real siege trebuchets are much more massive.
Great idea Andy! I'm sure, you will do it👍👍 greeting from Italy😘
thanks for the link..!
That’s great 👍
Incredible
Ohh this is exciting
3 attempts allowed... Make something that stores the energy from the first two attempts, only to release at the 3rd :D
Yes, nice idea, but it would only be allowed to be stored as gravitational potential energy, and the height/weight limits would still apply so I don't see how you could store extra energy. Using the extra height from table to floor would be the way to get a real advantage, only 2 people attempted this (and one of those was one of the organisers).
👍⭐👍