This golden sphere has a secret... it defies gravity!

this sphere has magical powers hold both ends of the string and you can slowly lower it and lower it and lower it but then it starts to go up again and then down again and then up up back to the top but how does it work and how could you make one for yourself I first came across this magical toy on a video from none other than Tim of grand illusions in this video titled rising golden ball he demonstrates this fascinating phenomenon of a ball seemingly defying gravity and rising back up a string other than a short description in the video there's no images showing the inner workings and sadly the link to buy one no longer exists so I simply had to figure it out for myself and make one for my own collection my first thought was to do a thorough googling and patent search to see if anything came up and while I on earth some wild ideas indeed it didn't get any closer to a diagram showing exactly what's going on here but remember that short description given the clues are all there Tim states that inside the ball is a pulley system two pulleys of different sizes with the thread round around both of them pulling the two ends of the thread makes the ball go up loosing the thread lets the ball to send pulley systems are capable of simply incredible things such as multiplying and redirecting force just watch Destin's video on the humble snatch block on smarter every day to see just how cool these systems are even 3d printed he's demonstrator which I can totally get behind but what of the pulley system in this secretive sphere well the hint is with those two pulleys of different sizes so to demonstrate I have one 16 millimeter pulley attached to a thirty two millimeter pulley giving us a ratio of two to one when you attach it in place and pull on the larger pulley 200 millimeters the smaller one quite expectantly moves up only half of that by 100 millimeters and due to the reduction you could live twice as much mass because we're moving twice as far but and bear with me this is where a gear pretty weird here we have exactly the same pulley but this time we're fixing the string from the smaller pulley in place and the pulley is able to actually move up and down in space what do you think will happen when I pull the string on the larger pulley down 100 millimeters pause the video and comment down below and let me know what you think because it's pretty confusing the first time you see it okay have you written your answers down below well as I pull down on a larger pulley the pulley goes up by 100 millimeters not 50 not 200 100 exactly the same amount I pulled down so what the heck is going on well remember the magic of pulley systems and their ability to redirect force well we're still seeing the same reduction as before with the fixed pulley two to one but it's also moving up by one and you can see the string to the larger pulley really does travel 200 millimeters but it's just moving upwards in the process this confuse the heck out of me for quite a long time so just to make sure it's not a fluke here's a three to one pulley and as expected moving it down 200 millimeters results in the pulley translating up 100 millimeters so it's 1 minus 3 so that's a 3 out the way and I did need a bit of help to get all this right so thank you Steve so how does the 3d printed version actually work well as with many things converting the theory to the real world is a lot harder than you might think and I went through countless revisions before arriving at this plant design for a start I tried a range of ratios to find which gave the most satisfying movement they're closer to 1 to 1 ratio gets the further out the ball moves in comparison to distance you pull down it also becomes a lot more difficult to move also the pulleys are offset from the center of the sphere and if you route them to the center through to tighter paths the whole mechanism binds up when you apply tension and the axle also needs to be held very securely and precisely in the center of the ball to avoid the pulleys being pulled into the top or bottom of the shell and rubbing and I use two bearings here to help it spin freely and minimize binding and keeping the threads on the pulley turned to be an incredible challenge in itself because if you just think about it both ends are just hanging loose it's not a closed pulley system like you'd normally have so when you let go of them you lose all the tension and they'll just derail off the pulley and jam the whole mechanism if you've ever let go at the end of like a fishing reel or filament for that matter you'll know the pain in the end I had to add a significant amount of material around the pulleys to help prevent the thread from jumping it also had to be easy to manufacture on standard FDM slash FFF 3d printers so the size was increased and clearance is added but this limitation meant the ball while functional was super ugly because it really has to be printed in this orientation and just in case you're not familiar this technology lays down molten plastic line by line layer by layer and the other sides of spheres are notoriously challenging to print as the plastic fights against gravity as it cools so to complete the look I designed this aesthetic step on cover which also helps gradually guy the filament thread back to the central axis as it leaves the sphere these parts are printed in gorgeous poly Acme gold and silver PLA filament and here's a cross section view of the whole design so you can see how it works so much for a simple sphere you can find links to this model in the video description if you'd like to print one for yourself and the hardest part of the assembly is threading the pulley you'll need to flange bearing of the F 623 Zed variety with three millimeters internal diameter and 10 millimeter outside diameter and they are pressed into place after threading to help catch the end of the thread the thread can still pull free if you pull too hard however so maybe consider melting the end into a little ball to help lock it in place or just dropping a tiny amount of glue into the hole after threading it through speaking of thread 15 pound test fishing braid is great with zero flex but I found upholestry thread has just a tiny bit of stretch to it it's available in a much bigger range of nicer colors plus it seems to cut into the plastic less so with that for the final design but both work would even get your hands on a long m3 bolt let's head cut off makes a perfectly good axle just thread that through your bearing and press it down to the slot it should reach the bottom of the slot and the police shouldn't feel bound up now time to thread the whole mechanism you want to wind the larger pulley only a good number of times this will determine how far up your sphere can rise when you pull on the bottom thread give yourself a bit of extra thread to work with and while keeping the pulley taut carefully thread the end through the holder and out the bottom this can take a few goes it's a bit tricky and I find it can help using some tape at the bottom to hold that thread in place once as it through just temporarily next run the smaller pulley thread through the top half and very carefully snap them together it'll only staff in place in the correct orientation so don't worry too much but you've got to make sure none of that thread derails inside the mechanism or it simply won't work now is a good time to test you should be able to hold both threads and pull on the bottom one it should result in the sphere rising up the string and when you release tension it should migrate back down to gravity don't force it if it binds up you might want to help guide it a bit but it's most likely a rough spot in one of the pulleys rubbing so open up again and see what might be sticking and correct it before you move on once you're satisfied you can secure in place yesterday covers to hide away the mechanism and snap it all together these covers are locked in place with the middle ring simply thread them into place and while holding both halves rotate the ring to lock them together cut your string to an appropriate length and tie a simple loop knot to each end so you can hold on to it and there you go you're ready to wow your friends and family as they try to figure out just how this magical sphere actually works this project has been a ton of fun to figure out and honestly it was a lot more challenging than I originally expected but the result is really neat and even now it's still incredibly magical if you'd like to make one for yourself you can find in the links in the video description or shared on my patreon along with source files there so you can actually modify and play with the design if you want to see you ADEs you might want to try a different pulley ratio or make the whole thing bigger or maybe smaller I'd love to see what you come up with and share your results with me at twitter at makers muse so thank you so much for watching if you want to see more strange mechanisms and designs then maybe consider subscribing and if Tim from Grande illusion sees this dude I would absolutely love to send you one of my 3d print designs for your collection thanks for watching guys bye

Channel: Maker's Muse

Views: 597,999

Rating: 4.8845625 out of 5

Keywords: 3d, printing, rising golden ball, magic trick, 3d printed toy, golden ball, rising sphere, defies gravity, download 3d print

Id: 7G5WpeJ1iG4

Length: 9min 21sec (561 seconds)

Published: Fri Feb 28 2020