YellowMarble Posted September 14, 2015 Report Share Posted September 14, 2015 A row of steel 1/2 inch marbles speeds down a 200 feet long Lego train track! At the end of the track there are a large number of bells. You'll see also a night train with glowing marbles. Link to comment Share on other sites More sharing options...
Steph Posted September 14, 2015 Report Share Posted September 14, 2015 Magnificent! Link to comment Share on other sites More sharing options...
Hoody Posted September 22, 2015 Report Share Posted September 22, 2015 Hello, just sitting in the office at a break I am not able to view youtube. I will try it when at home at the week end. But tell me, please, how fast are the marbles at the end of the track? Regards Hoody Link to comment Share on other sites More sharing options...
YellowMarble Posted September 22, 2015 Author Report Share Posted September 22, 2015 Quite fast, but you should wait to the week end. Link to comment Share on other sites More sharing options...
Hoody Posted September 25, 2015 Report Share Posted September 25, 2015 Oh, how cool! And the sequences in the dark - really great stuff. I need to get also some those glowing balls. I figure out a speed of roughly 1 meter per second just before reaching the bells. Would you tell us the slope you have used (millimeter of height per meter of length)? Link to comment Share on other sites More sharing options...
YellowMarble Posted September 26, 2015 Author Report Share Posted September 26, 2015 The slope was around 3 lego unit (near 30 mm) height per 8 track segments (1,024 m, 40 inch). Link to comment Share on other sites More sharing options...
Hoody Posted September 28, 2015 Report Share Posted September 28, 2015 In other words roughly 1,7° of angle. Do you ever think (or even estimate) friction losses? Or do you just try until you think there is enough slope to keep the balls rolling? Link to comment Share on other sites More sharing options...
YellowMarble Posted September 29, 2015 Author Report Share Posted September 29, 2015 It keeps rolling, regular 5/8 marbles has a low speed, a run takes more than 4 minutes. The 1/2 inch bearing balls are lots faster. I can also use 3/4 inch ball bearings, but they gone too fast and fly off track. Link to comment Share on other sites More sharing options...
Hoody Posted September 29, 2015 Report Share Posted September 29, 2015 That is in line with my assumptions and findings. The glas marbles are nonhomogenous and so loose energy (speed). The steel balls are nearly perfect spheres and so they gain more energy from the same height difference. And with the bigger diameter the geometry changes dramatically - reducing the maximum speed for a certain radius. I think that it is not really speed but the diameter. Just take a piece of paper a ruler and a compass (zirkel = de passer) and do a drawing of both geometris in a certain scale 1:1 or so.You will easily see that with the bigger diameter the angle of the sphere to rail contacts is smaller. This smaller angle has less lateral support than with the smaller diameter. It is exactly as with a banked curve (= to hoog bocht?). Less banking means less speed until things get critical. Link to comment Share on other sites More sharing options...
YellowMarble Posted October 8, 2015 Author Report Share Posted October 8, 2015 See this video, larger steel balls goes faster and they makes a silly noise :-D Link to comment Share on other sites More sharing options...
Steph Posted October 8, 2015 Report Share Posted October 8, 2015 Zip! Link to comment Share on other sites More sharing options...
skoronesa Posted February 6, 2016 Report Share Posted February 6, 2016 This is awesome. That is in line with my assumptions and findings. The glas marbles are nonhomogenous and so loose energy (speed). The steel balls are nearly perfect spheres and so they gain more energy from the same height difference. And with the bigger diameter the geometry changes dramatically - reducing the maximum speed for a certain radius. I think that it is not really speed but the diameter. Just take a piece of paper a ruler and a compass (zirkel = de passer) and do a drawing of both geometris in a certain scale 1:1 or so.You will easily see that with the bigger diameter the angle of the sphere to rail contacts is smaller. This smaller angle has less lateral support than with the smaller diameter. It is exactly as with a banked curve (= to hoog bocht?). Less banking means less speed until things get critical. I dont think it has to do with how spherical they are so much as the weight. I agree that banking is needed but i see how it could be difficult with that track. Link to comment Share on other sites More sharing options...
YellowMarble Posted February 6, 2016 Author Report Share Posted February 6, 2016 Thanks, I don't make calculations, but i test different types of marbles and look what happen/ Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now