TomSunny007

Here is a new video testing Imanol's hook design, 56902 pulley wheels, and multiple points for pulling string. Feel free to comment. I'm currently wondering if there is any point in going further.

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Imanol BB Do you mind if I show your hook design images (and one of your comments) on a new video? I tested the design and it works great. :) Tried to contact you on your yahoo email. I'm not yet allowed to send private messages on Eurobricks.

Testing links to a member profile. TomSunny007 @TomSunny007 link https://www.eurobricks.com/forum/index.php?/profile/179055-tomsunny007/ TomSunny007 Scene

Thanks for all the effort. To me the left one with a single axle feels the most promising. I fear those short 2L axles will pop out of the holes when all that heavy load starts to bend and twist parts. The use of 3x5 frame is very good. Those liftarms may be the weak point as in my video 2 liftarms were able to hold only 30 kg. The pins are also a question mark how well they withstand load. Anyway, this looks so good I'll probably try it sometime. :) Thanks. That 56902 looks perfect. Another pin holed small wheel I found is 30155 but it doesn't have that nice groove for cord. Not bad. 44 kg and probably a lot more. Funny how you used exactly the same configuration as I: 4-fold purchase and 15:1 gear ratio, at least in one of the pictures. Well, this is a dilemma for me. I will brake more parts if I continue making these kind of experiments. Next I have been thinking about measuring Lego axle breaking/deformation point. Certainly some viewers will feel bad for those destroyed and mishandled Lego pieces. That's not the way they are supposed to be used. But also, I think many find the engineering and science behind these experiments interesting and useful. You can learn something from them. And then some viewers just have fun seeing things blow up. I guess I will just go on breaking parts and see what kind of feedback I get.

Looks beautifully simple compared to my version. :) The main reason I had to make it so complicated was so that all pulleys rotate on different axles. I once tried a quadruple tackle (or what those are called?) with two pulleys on the same axle, kind of the way those Liebherr modules have many pulleys side by side. It was simple and strong, but couldn't lift as much, probably due to extra friction because pulley wheels don't rotate at the speed of the strings anymore. I wonder if there are Lego pulley wheels that can rotate freely on an axle. The idea to use a strong master beam to connect all pulleys is certainly worth a try. I think the pressure from the string was just too much and started to eat through the bush and axle. If I had continued, the axis probably would have broken apart. Here is another case where you can see it happen: https://youtu.be/umN2iHsw3UY?t=62 That's an amazing idea. Why I never thought of those 2x2 round bricks? Even if torque decreases because of the string distance to axle, you can just add more gear ratio to compensate that and the downward force to the axle is still the same. I wonder how well (without friction) those technic turntables rotate under heavy load... Yeah, I know. This was just an experiment to find the absolute limit. Building a whole crane with that load would probably be impossible. The Liebherr LR 11000 model by Dawid Szmandra has 9 kg load capacity (lifts a whole chair on the video), which is pretty amazing already. Besides structures, also the main axle that collects string would be significantly weaker if made so that you can lift things more than 1 mm to the air as in my experiment.

Hello Everyone Newbie here. I've been trying to figure out what is the largest mass you can lift using Lego parts only (except for strings) and one Lego PF Medium Motor. So far, I have managed to lift 21 kg with pulleys/tackles, 55 kg with gear systems, and a little over 100 kg with both gears and tackles. Here is a video I made of the progress, starting with a simple single tackle driven by 24 and 8 tooth gear train, and then just increasing ratio step by step and fixing problems as they arise: Not sure if I can go much further. Axles are starting to break.