I'm no scientist but it's likely because due to the pull from the weight the car needs to weigh at least as much or more otherwise it looses the needed traction. Which doesn't happen when it pushes the weight.
Anchor points and traction. Make the angle to the anchor point be lower and where it attaches to the car higher. Then the weight will help push the car into the ground instead of lifting it off the ground. Imagine a tow truck. Edit : A great example is at 2:50, see the angle from the attachment point on the car, the first anchor point of the pulley system is above the car attachment point, the weight will be lifting the back tires off the ground, giving the front wheels extra traction allowing itself to rip itself in 2
Friction. Lifting a weight of more than the weight of the car would require a coefficient of friction over 1, which is uncommon. However, to push more than the cars weight, all one needs is for the normal force of the object being pushed times it's coefficient of friction to be less than the object pushing it. The main difference comes down to slippery plastic vs rubber on carpet.
Besmirching the FWD by making a rear engine FWD vehicle, so unlike any real vehicle. No wonder it couldn't do anything. There has to be weight on the drive axle to get grip.
6:08 - please don't increase the weight while the structure moves already. There static traction (the one to start moving) is higher than the dynamic one (when things are in motion). The difference depends on many things, so to keep tests consistent you should restart the car each time you add weight.
All in all it doesn't make that much of a difference, since the car pushed the 7kg dumbell from still position. So it can probably push all the other ones just fine.
The tower tilted on the RWD pull test, resulting in the rope above the wheel centerline. The tension was pulling the rear wheel up, causing it to lose grip.
I think MKII could've pulled the 122g, if the tower weren't leaning away, thus raising the pivot point to above the connection point on the car. this essentially lifted the rear of the car, reducing traction. keep the closest pulley on the tower below the attachment point on the car, it'll help it dig in.
I love it, but some notes: - the push test is skewed, as you changed the surfaces area on which the weights are places. For a compareable result, it they weight should always be the same surface area touching the ground. - for the pull test if would probably have been better the build a contruct with two vertival support beams, instead of just a „crane“ type. Less energy during pull would have gone into tranforming the structure ☝️
As a fellow creator, love the videos! Next time can you omit the corporate training background music? It was a bit distracting, I would rather just listen to the lego sounds.
Thank you for the great video. I've been struggling with the lack of traction on a mobile two-wheel drive crane for a while now, and your version of 4x4 drive could fit in my chassis, making my life easier :) So please, if you could upload a tutorial or other procedure somewhere, or video/pictures with a detailed look at all parts of the build. Thank you very much.
Mount the "hook" as high as you can on the back of the vehicle to get more weight transfer from the front of the vehicle to the rear. Increasing traction while pulling.
Well done quality wise. I deal more in the realm of statics rather then dynamic but a few thoughts: Generally, 1) Tires need to over come the friction applied in order to move, there are two parts to this Static and Dynamic friction. Think of it like breaking free and sliding friction. The breaking free force is always going to be higher then the sliding force. These values are (generally) determined by [pressure (i.e. weight) over a given surface area multiplied by a factor based on materials involved], if the wheels are slipping then you are friction limited and either need to change the materials involved, decrease contact patch or increase weight acting on the wheels. 1.1) If your wheels aren't spinning at all then your are torque limited in the current configuration. 1.2) Torque is "lost" in a couple of ways, a significant one is at each joint in an axle configuration. Joints (like the FWD) don't transfer torque very well, using a straight line axle or a direct gear setup would have worked better. Also the FWD was torque limited as well by lack of weight over the driving wheels. 2) Torque can be manipulated by altering the gear ratios as you move through a drive train, however each additional gear in a series adds some torque losses (this is why modern transmissions actually switch drive paths as gears change rather then just adding more gears). If you have a large gear going into a smaller gear you will spin slower (i.e. less HP), but have a higher torque output. This would allow you to lift or pull more weight. 3) Lifting vs Pushing: Excellent observation, in addition to things to others mentioned. Each pulley adds some friction that needs to be overcome, using a single pulley and lifting up through a hole would eliminate that. Also the energy that goes into deforming the tower is energy that can't be used to lift that material upwards. 3.1) Snatchblocks are the key to lifting more weight in a given configuration (see: ruclips.net/video/M2w3NZzPwOM/видео.html also check out EngineeringExplained for really nerdy automotive engineering)
You should create a somehow of gearbox, because currently you test only engines power. I you will play with different size of cogwheels, you can increase torque.
I once made a linear actuator out of lego, a couple of metal washers and powered by an XL motor. It managed to push around 30 kg and lift around 10 - 12 kg before it broke. It was a simple build with a long axle with 6 or 7 of the old wormgears. Thanks for the video. It was very entertaining :)
Kind of what I did for my current project^^ Reworked the engine unit (with subtractor...Is for a tank) several times, so it withstands the forces due to the high weight^^
I would love to see how much weight the different cars lift with different pulley systems. Like how far can you go with weights (I it can be calculated but seeing it in motion is more fun).
So what's the actual point of the "gear box" with the small beige gears inside of it. The latest technic batmobile has it and I've found it doesn't do anything lol.
I wonder if anyone makes a high torque lego compatible motor, because that would be great for this, and some lego compatible tyres with real car tyre compounds.
It turns out that the vehicle cannot lift up a load of more weight than itself, but it can push. Can anyone explain this?
I'm no scientist but it's likely because due to the pull from the weight the car needs to weigh at least as much or more otherwise it looses the needed traction. Which doesn't happen when it pushes the weight.
Beacause the weight lifts up the car and i loses grip-2nd Newton and 3rd Newton's law
Anchor points and traction.
Make the angle to the anchor point be lower and where it attaches to the car higher. Then the weight will help push the car into the ground instead of lifting it off the ground.
Imagine a tow truck.
Edit : A great example is at 2:50, see the angle from the attachment point on the car, the first anchor point of the pulley system is above the car attachment point, the weight will be lifting the back tires off the ground, giving the front wheels extra traction allowing itself to rip itself in 2
Friction. Lifting a weight of more than the weight of the car would require a coefficient of friction over 1, which is uncommon. However, to push more than the cars weight, all one needs is for the normal force of the object being pushed times it's coefficient of friction to be less than the object pushing it. The main difference comes down to slippery plastic vs rubber on carpet.
if the car is less heavier than the load it has no grip to pull the load
Besmirching the FWD by making a rear engine FWD vehicle, so unlike any real vehicle. No wonder it couldn't do anything. There has to be weight on the drive axle to get grip.
6:08 - please don't increase the weight while the structure moves already. There static traction (the one to start moving) is higher than the dynamic one (when things are in motion). The difference depends on many things, so to keep tests consistent you should restart the car each time you add weight.
Yeah this was a big one, he should have restarted the test every time
This is the most scientific comment section I have seen
I also hate how he added weight to only some of the cars and different amounts even then.
All in all it doesn't make that much of a difference, since the car pushed the 7kg dumbell from still position. So it can probably push all the other ones just fine.
The tower tilted on the RWD pull test, resulting in the rope above the wheel centerline. The tension was pulling the rear wheel up, causing it to lose grip.
I cant look at the tower tilting without Any help by other Lego parts. I dont know if je really want to treat his Parts in this way. I couldnt😂
Nice video! I really love the quality of your videos :)
I watch both of you! Nice to see ya here!
Thanks!
I love your videos
3:38 I love how it towed the whole pull test setup before it broke!
I think MKII could've pulled the 122g, if the tower weren't leaning away, thus raising the pivot point to above the connection point on the car. this essentially lifted the rear of the car, reducing traction. keep the closest pulley on the tower below the attachment point on the car, it'll help it dig in.
I love it, but some notes:
- the push test is skewed, as you changed the surfaces area on which the weights are places. For a compareable result, it they weight should always be the same surface area touching the ground.
- for the pull test if would probably have been better the build a contruct with two vertival support beams, instead of just a „crane“ type. Less energy during pull would have gone into tranforming the structure ☝️
Nice idea 💡. Thanks!
Good point
The pull test was flawed since the tower ended up leaning back pulling wheels off the ground.
Actually, the friction does not depend of the surface area. The test is not skewed
Your videos were so good I wonder where is all of your viewers
As a fellow creator, love the videos! Next time can you omit the corporate training background music? It was a bit distracting, I would rather just listen to the lego sounds.
Your videos are the best ones, I think that you can get to 100.000 fast if you continue like that😃😃😃
Thank you for the great video. I've been struggling with the lack of traction on a mobile two-wheel drive crane for a while now, and your version of 4x4 drive could fit in my chassis, making my life easier :) So please, if you could upload a tutorial or other procedure somewhere, or video/pictures with a detailed look at all parts of the build. Thank you very much.
I love that you let complete failure happen before stopping even though you see it coming.
videography top notch
Well done for using metric measurements. 👏👏👏👏
It is very strong and very good I love your videos
Thank you!
@@DrEngine you are the best 👌👌👌👌👌👌👌👌👌👌👌👌👍👍👍👍👍👍👍👍👍
I am very impressed how did you made in these vehicles of Legos👍👏🏻👌
I am subscribed as well
Wow, this video is amazing! I learned so much from it. Keep up the great work!
please make more videos like this they are so relaxing and wonderfoul!
Power to weight ratio is the key 👍🏻
For inproving the grip you can put lego big gears like wheels and put bricks with toths for having a 100% of friction.
WHOA SICK!
Mount the "hook" as high as you can on the back of the vehicle to get more weight transfer from the front of the vehicle to the rear. Increasing traction while pulling.
Nice video!!! 👍👍👍
Yo that background instrumental music of pumped up kicks is so soothing
Well done quality wise.
I deal more in the realm of statics rather then dynamic but a few thoughts:
Generally,
1) Tires need to over come the friction applied in order to move, there are two parts to this Static and Dynamic friction. Think of it like breaking free and sliding friction. The breaking free force is always going to be higher then the sliding force. These values are (generally) determined by [pressure (i.e. weight) over a given surface area multiplied by a factor based on materials involved], if the wheels are slipping then you are friction limited and either need to change the materials involved, decrease contact patch or increase weight acting on the wheels.
1.1) If your wheels aren't spinning at all then your are torque limited in the current configuration.
1.2) Torque is "lost" in a couple of ways, a significant one is at each joint in an axle configuration. Joints (like the FWD) don't transfer torque very well, using a straight line axle or a direct gear setup would have worked better. Also the FWD was torque limited as well by lack of weight over the driving wheels.
2) Torque can be manipulated by altering the gear ratios as you move through a drive train, however each additional gear in a series adds some torque losses (this is why modern transmissions actually switch drive paths as gears change rather then just adding more gears). If you have a large gear going into a smaller gear you will spin slower (i.e. less HP), but have a higher torque output. This would allow you to lift or pull more weight.
3) Lifting vs Pushing: Excellent observation, in addition to things to others mentioned. Each pulley adds some friction that needs to be overcome, using a single pulley and lifting up through a hole would eliminate that. Also the energy that goes into deforming the tower is energy that can't be used to lift that material upwards.
3.1) Snatchblocks are the key to lifting more weight in a given configuration (see: ruclips.net/video/M2w3NZzPwOM/видео.html also check out EngineeringExplained for really nerdy automotive engineering)
Just amazing 🙂 Thanks for the comment!
I like how the gearbox detaches to prevent Lego and motor damage. very cool stuff
I watched until the end, this was good. 🤙🏼
congrats on 200k subs! 👍👍👌👌
Thank you so much 😀
You should create a somehow of gearbox, because currently you test only engines power.
I you will play with different size of cogwheels, you can increase torque.
the cams look great keep it up
Glad you like them!
I once made a linear actuator out of lego, a couple of metal washers and powered by an XL motor. It managed to push around 30 kg and lift around 10 - 12 kg before it broke. It was a simple build with a long axle with 6 or 7 of the old wormgears.
Thanks for the video. It was very entertaining :)
Great video, I keep learning and having ideas of what I can do.
When he said workout done, that was just Mondays. By Friday he was replacing most of the world's freight trucks 🚚 lol
Nice video, i want se 4 engine with more weels
3 tests on tomorrow and I'm watch someone lifting with lego at 2am. Me: Worth!
friction in push test maybe add a front cargo
WOW tes véhicule sont très puissent
Would be cool to see a burnout car build. High wheels speed vs torque getting a perfect balance
Kind of what I did for my current project^^ Reworked the engine unit (with subtractor...Is for a tank) several times, so it withstands the forces due to the high weight^^
Wow, I would like to see your project
@@DrEngine Is still under construction...To give an idea: A Landkreuzer P1000 Ratte with a total of 16 motors...7 in the engine unit...
thanks to the friction force, without the friction force lego is very strong
Damn, the danish sure have quality plastics
My idea for next video: do a lego saw that can cut wood
It's about *drive* it's about *power* we stay hungry we devour
You shouldn't have done it through the differential, you should have done it directly
Now I can say I've hit the gym without actually hitting the gym!
for the fwd car it needs more front weight
My guy destroyed his motors for us to enjoy the video
Roses are red,
Violets are blue,
I'm subbed to Dr.Engine,
You should be too.
(Heart please)
So this youtube channel teaches us learn from your mistakes
♂️boss of the gym ♂️
Why did you add weight at 3:00 but not the others? And unit 1 had a diff, which could have benefited from the weight.
I wish to see your face in some video 🤩🤩
Do a mix of all of them
I would love to see how much weight the different cars lift with different pulley systems.
Like how far can you go with weights (I it can be calculated but seeing it in motion is more fun).
Subscribed cause I love physics and science. Keep putting out videos my dude!
Thanks for the sub!
You should make the next model a 6x6 with 3 motors
3:42 Trust me, I'm an engineer
I’m surprised the crane didn’t rip apart near the end. The arm looked like it was seconds away from ripping itself to shreds.
one thing, the FWD model had an open differential whereas the RWD one was locked
bros gonna make a lego robot army one day
man has an umbilical cord like an Evangelion
I love the transitions between the videos and the concept is really cool.
Keep it up 👍
Thanks! Glad you like it 😊
Never miss peg day
did something similar in a robotics group i was part of about 8 years ago, our bot was able to pull about 60 pounds
DAMN
I bet you could really smell that motor during this. 😆
The power of gravity
Boss of the GYM
Awesome
I'd definitely recommend having a stronger structure to handle the weight of what's lifted. As is, you risk breaking pieces.
Nice
The progression is amazing. Just when it looks done for you modify it for more
Thanks!
Is that pumped up kicks in the backround?
Nice video format, exceedingly jealous I don't have access to this much Lego, keep up the good content
Thanks! Glad you like it 😊
As a test, i loaded 9 (nine!) kilos on 42129 deck, and it moves on as if nothing happened! That's unbelievable! Great surprise for me!
Love how the test stand failed more than the cars.
Super cooool
Thanks!
Americans are like: “nice video but wtf the “g” means?” Lmao
zarąbisty odc
Thank you!
Would have been better without the free music in the background
it has more traction with more weight because it stops it from hopping
Thanks to the gears, we lost speed, but added a lot of torque
It might move even more if it got a short (slow) run up and bumped into the load it start it moving
So what's the actual point of the "gear box" with the small beige gears inside of it. The latest technic batmobile has it and I've found it doesn't do anything lol.
Are those factorio sound effects? 😅 Great vid keep it up.
Thanks!
Thd crane isnt stable enough.
Love how the top whells fell off the stack when you put down that dumbbell though
What camera do you use? these films are fantastic.
I realise that a Lego car can lift more than me..
what does that dark grey cylinder with the tan small gears inside do??
I wonder if anyone makes a high torque lego compatible motor, because that would be great for this, and some lego compatible tyres with real car tyre compounds.
Also can you give us the instructions on how to build something like these machines?
kurde co ja oglądam. ale łapkę w górę zostawiam :p
I did this with a knex car and made it pull like 30lbs using 4 motors
You need your attachment point higher than the pulley
Can you make also 6x6 and 8x8? (and tracks of course)
Very nıce👍👍
Where do you get all these peaces and what is it called
You made this with which lego model ?
can you build a crane, to lift up as much weight as possible?
I am done ☺️☺️☺️................
U should use super glue to make it stronger