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.

Edited January 3, 20187 yr by TomSunny007

Hi, welcome to Eurobricks, i really like the experiment you have done here, its really impressive how one can create such a massive power by just arranging gears and pulleys, maybe you could make a modification to the tackle, and build it like the hook of a heavy lifting crane to make it much more stronger and reliable, i attach an image for reference, it is a Liebherr LR13000 Hook, it is composed of 6 "modules" of 5 pulleys each one, which are then placed in 2 "groups" of 3 modules each, and the 2 groups are then connected to the main block or structure:

Maybe you could make a similar version in Lego, for example, making a "module" of 2, 3 or 4 pulleys, and making about 3, 4 or more modules, and connect them individually to a rigid and strong beam, this way the stress in the parts would be drastically reduced, as the force is much more distributed along all the pulleys, however, your design has proven to be pretty and strong too, holding 100Kg is not easy task and is almost sure that some pieces will get hurt.

I think you did an amazing job sharing this experiment, and i hope to see more of your creations in a future.

Interesting but I doubt you're gonna be able to build anything that's gonna support that 100 kg's effectively

Very impressive experiment. Could you explain what happend to the axle at 6:25? Did it break or twist apart?

Wow, great experiment and great video!  I am amazed that it can take so much weight, but those poor parts!

To go even further, maybe you could reinforce axles by running them through 2x2 round bricks, or somehow replacing the axle bearings with technic turntables...

 

7 hours ago, Carsten Svendsen said:

Interesting but I doubt you're gonna be able to build anything that's gonna support that 100 kg's effectively

He's already done 100kg!

Edited January 4, 20187 yr by aeh5040

Welcome!

Very interesting.

Didn't thought, that Lego can handle this much

3 hours ago, aeh5040 said:

He's already done 100kg!

Yes I know, but that's on a standstill and very sturdy construction. You still need to build some sort of crane for it, and that's what I'm referring to.

Super impressive! You broke so much but well worth.

Welcome! VEry exciting and interestind experiment! Thanks for sharing!

23 hours ago, Imanol BB said:

maybe you could make a modification to the tackle, and build it like the hook of a heavy lifting crane to make it much more stronger and reliable, i attach an image for reference, it is a Liebherr LR13000 Hook

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.

21 hours ago, Sjoemie himself said:

Could you explain what happend to the axle at 6:25? Did it break or twist apart?

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

14 hours ago, aeh5040 said:

To go even further, maybe you could reinforce axles by running them through 2x2 round bricks, or somehow replacing the axle bearings with technic turntables...

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...

22 hours ago, Carsten Svendsen said:

Interesting but I doubt you're gonna be able to build anything that's gonna support that 100 kg's effectively

Yes I know, but that's on a standstill and very sturdy construction. You still need to build some sort of crane for it, and that's what I'm referring to.

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.

Wow, really impressive! Several of my projects are gravity powered clocks, and so far I was afraid of going past 3kg - now I see that with proper reinforcements, much more can be achieved without brick damage. Thanks 

Hey Tom, i made some experiments in LDD, and made some kind of heavy duty hook, 2 versions actually, the right one uses the cross hole wheels, and each one has its own 2L axle (the red ones in the pictures) for independent rotation (note that the 2 parts with the 1 1/2 pins at the sides are meant to be placed in the 3x5 frame to avoid the 2L axles from displacing and popping out), now, left one uses wheels with pinholes, which means that a single axle can go through all the pulleys and they will still be able to turn at different speeds, here are some pictures:

I hope these designs can be inspiring for you, i will try to see if i can think of some improvements, but so far that is what i have achieved.

All these experiments brakes parts so don't be fond of them too much.

8 hours ago, Imanol BB said:

Hey Tom, i made some experiments in LDD, and made some kind of heavy duty hook, 2 versions actually, the right one uses the cross hole wheels, and each one has its own 2L axle (the red ones in the pictures) for independent rotation (note that the 2 parts with the 1 1/2 pins at the sides are meant to be placed in the 3x5 frame to avoid the 2L axles from displacing and popping out), now, left one uses wheels with pinholes, which means that a single axle can go through all the pulleys and they will still be able to turn at different speeds, here are some pictures

For a six fold purchase to raise and lower a heavy bucket chain excavator boom I used these.
They have a deeper groove than wedge wheels and keeps the cord in place better.

They come in two versions:-

LEGO Rim Narrow Ø18 x 7 and Pin Hole with Shallow Spokes (56902)

LEGO Rim, Narrow Ø30 x 14 with Axle Hole (56904)
 

I made that kind of experiments a long time ago for a mindstorms contest: http://philohome.com/hoist/hoist.htm

Just tested a pneumatic cylinder using a motor pump and it generated 4.8kg of force. So theoretically I guess 21 of those could lift 100 kgs, 210 could lift 1000 kgs and so on.....I guess.

On 03/01/2018 at 9:33 PM, Carsten Svendsen said:

Interesting but I doubt you're gonna be able to build anything that's gonna support that 100 kg's effectively

I think it's possible, just don't have the money to try it 

On 1/5/2018 at 2:18 AM, Imanol BB said:

Hey Tom, i made some experiments in LDD, and made some kind of heavy duty hook, 2 versions actually, the right one uses the cross hole wheels, and each one has its own 2L axle (the red ones in the pictures) for independent rotation (note that the 2 parts with the 1 1/2 pins at the sides are meant to be placed in the 3x5 frame to avoid the 2L axles from displacing and popping out), now, left one uses wheels with pinholes, which means that a single axle can go through all the pulleys and they will still be able to turn at different speeds, here are some pictures:

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. :)

On 1/5/2018 at 10:58 AM, Doug72 said:

For a six fold purchase to raise and lower a heavy bucket chain excavator boom I used these.
They have a deeper groove than wedge wheels and keeps the cord in place better.
They come in two versions:-
LEGO Rim Narrow Ø18 x 7 and Pin Hole with Shallow Spokes (56902)
LEGO Rim, Narrow Ø30 x 14 with Axle Hole (56904)

Thanks. That 56902 looks perfect. Another pin holed small wheel I found is 30155 but it doesn't have that nice groove for cord.

On 1/5/2018 at 11:00 AM, Philo said:

I made that kind of experiments a long time ago for a mindstorms contest: http://philohome.com/hoist/hoist.htm

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.

On 1/5/2018 at 8:15 AM, Aleh said:

All these experiments brakes parts so don't be fond of them too much.

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.

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.

In case you are unaware, you can PM after 10 posts. Hope this helps, I remember reading this thread with great interest when you first started and would love to see any updated stuff or progress. 

5 hours ago, TomSunny007 said:

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.

Of course, you can use them without any problem, i'm glad the design was a success, i hope to see it in action in the video.

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.

 

Those pieces held up surprisingly well for holding up 500 lbs. Very interesting and well presented video, thank you.

Well, i must say i'm impressed, never thought that the hook would take that much weight before breaking, really amazing experiment.

what if you made it with a 8 pulley system. such as this some how ? would that make it stronger or weaker?

On 9/8/2018 at 8:29 PM, divvless said:

what if you made it with a 8 pulley system. such as this some how ? would that make it stronger or weaker?

 

The only problem with that design is the pullies resistance and how to attach them, and as far as i know they aren't that much stronger than beams or other bricks.