Thank you Aaron and David for being enablers to Joel and his Antics 🤣🤣🤣 #FeelTheMagic

Those toy pullback cars are incredibly clever, they have a mechanism that switches gear ratio when you release them so they can go much farther than you pulled them back

I've seen that other mystery rubberband powered car in person and spoke to the builder when I was a crew tech out at the bonneville salt flats. It was made by one of George Poteet's guys. There were 2 banks with different gearing...one for initial acceleration off the push truck, then a second for top speed. I never got to actually see it run but if I recall, he was shooting for something like 50mph with it. Was a super neat contraption. I have detail pictures somewhere on an old phone in my closet 😂

My immediate thought was to use a scaled up watch spring. I would love to see you revisit this with more research. Perhaps start with scale models?

The problem of the wheels locking up is a problem at toy scale as well. Thats why we push down as we pull back with those little cars. I think that finding a way to overcome that (potentially a hand crank with some major leverage?) and fixing the spring design to something like a watch spring could help get the speed you want. Sick work so far though. It looks really fun even at current speed. Haha

I actually have a lot of respect for posting semi-failed projects because it really reminds everyone of how many ideas and projects don't work that make the ones that do work feel all the more impressive.

Could put PVC pipes over the birdcage bars to act like a roller bushings for the rubberbands

Thank you, Aaron and David, both for all of your help with these crazy ideas.

Everyone needs a John in their life. Plenty times I've started a project, got to a point, then just gave up... Sometimes it just takes a random person showing interest to help give you that final push. Aaron and David still deserve a lot of praise, but there's just a certain feeling you get from a random dude being interested in something, that even the most supportive friends can't replicate. Really cool design. I hope it inspires others to take it further, even though this fully worked. ;)

Laugh all you want but this mf gonna come for you! (at 5 kilometers per hour for 10 seconds once every 2 minutes)

You might wanna check out the spring mechanism of a vacuum cleaners cable reels. It's a metal strip that wants to roll up into one direction, but then you have a bigger roll that bends it in the opposite direction. Simple as that. They are actually quite strong (and sharp!), but they don't increase in strength even when pulled all the way out. I have built a compressed air hose reel with just two of them, and it's just barely enough, but it works! It's also probably pretty cheap too! You might be able to make a very wide version of it. Also, they go FAST!!! If you, while disassembling such a reel, let go at any time, the entire thing goes super speed and then breaks the spring... Just a suggestion!

I think the key is using the same method that airplanes use for their rubber engines. They twist the rubber band around itself instead of wrapping around a shaft. This allows you to store much more energy. In fact this is how that dragster worked according to that photo that you showed. Also switching to a lower gear when winding would help you to not have to pull the car back so much. Thank you Aaron and David! Edit: now that I'm thinking about this I remember having a hotwheels car that had a rubber engine. It also used the same method of an airplane!

Thank you David and Aaron for helping Joel make these awesome videos

So Joel there's a thing you may want to consider if you want to revisit this. The spring option is a great idea but you need to find "stiff" spring not necessarily a larger spring. There's some equations you can use to find these things and effectively take into account the force the spring is applying to the shaft along with the force that is being applied to the tires. Your goal is to overcome the static friction force first and then continue to push through the sliding friction. F=ma so the greater the force difference the faster the acceleration. If you also create somewhat of a gear system where the spring only engages when you want it to and then disconnects from the axel allowing the car to continue forward under its own momentum that would allow you to use the initial push that the spring has given you without the spring re winding back up and killing your momentum. over all this was a great video and really great refresher for my kinematics from my physics classes since I'm taking the mcat in a few days. Thank you as well aaron and david for letting joel do his thing with your stuff.

Multiple spiral springs that are in toys are used all the time for bigger applications. I would definitely try spiral springs or nested coil springs.

I have so much admiration for persistence in frustrating projects that have uh... no... actual useful application, and are simply an idea you want to make.

Thank you david and aaron! This vid was dope joel, really put the spring in my step

Thank you all for these amazing videos! Every time you put one out I think "he can't get more ridiculous than this" and every time I am proven wrong!

I love your videos man keep up the good work!

A for effort. I can't imagine the tedium of gluing those bands each time! I do hope inspiration comes for something that will bring the magic!

You all came together to do a really cool thing and that is just awesome. Neat project!

I love watching you try. You are my kind of dude

Thank you Aaron and David for being enablers to Joel and his Antics

Somewhat different scale, but reminds me of a project I did in school for a science project. Making a mousetrap powered car. I possibly cheated a bit, with my grandpa, uncle and dad all contributing ideas, designs and parts, although I did technically build the whole thing myself. Tiny ball bearings, high quality fishing line around the axle attached to the mousetrap arm and CD ‘coasters’ as wheels (at the time, burning a CD was not a guaranteed success, but far and away was the most economic way to store data. There was invariably a spindle of failed burns, affectionately called coasters). The small axle diameter and the huge wheel diameter made for an excellent ratio. My car couldn't drive across a desk because of lack of traction, it would just spin the wheels. But on carpet or concrete, was an absolute beast. I won that one by orders of magnitude.

You didn't make the "jump to light speed" but you did prove you have very cool friends. Oh, and you don't give up easily. :)

Hello from Sweden

Thank you David, we all need a David in our lives

Thank you david and Aaron we appreciate all that you do.

If you want to go anywhere you will need longer rubber, which is also stronger, a "kinetic rope" (used in the field to recover off-road cars) with a few pulleys will do an amazing job.

You the man David 🙏🏻

Great work man! This must have taken forever to redo the deign over and over! I had this idea since i was a kid too! I thought I was going to have to cross this off my idea list but now I think we have our collaboration idea. We'll get you to the cut off speed you're looking for, then take you to holy $#!%. Huge respect to Aaron and David, you guys rock!

Got a new favorite channel to binge! Thanks to you, Aaron, and David. Cheers!

David is single handedly changing my opinion of people who wear bluetooth ear pieces after like 2011. For the longest time every person I have met who is wearing one of those has just been so douchey but david is so cool. Also Aaron's timing was amazing literally today I asked a garage door guy if they did other doors, as my works back door got kicked in last night. The guy said "We dont do anything else" in a very similar way to aaron. Both of those guys are great.

thanks David and Aaron for their work

That was cool mate, you shouldn't be so hard on yourself. You are creating joy. Keep on creating Joel.

I hope Aaron & David see really positive business from helping with your projects Joel. Thanks for being good friends to him guys.

All the work you put into this. Can’t believe you have gotten more traffic

On the forum for the drac car there's pictures of how it actually works and it's real straight forward but complex due to the amount of parts

Some things you probably want next time: 1. Don't have a shaft running through the spring, have the shaft reach just into the cage and have it terminate to a plate that you can mount your torsion spring to. You still get the safety from it and don't have to worry about awkward winding or spring diameter as much. It's also really useful to get better geometries going like twisted rope bundles if you want to get away from metal springs again. 2. Constant force. Right now you are doing the charging and discharging of your system at linear force over displacement curve, you're going with hook's law. That is an issue because it means that the energy stored inside your system in terms of the peak force / torque F and the total (angular) displacement L is 0.5 * F * L. While in a constant force system you get just F * L. Torsion vs linear doesn't matter, the physics is equivalent with angular displacement replacing linear displacement. That factor 2 is big game, you're 40% slower than you should be and/or put twice as much stress on everything There are two ways of getting there: 2.1 Preloading your spring. You know twisted rope catapults? Take a rope bundle, carefully wind it up, letting the torque increase to your desired level. Then only put an additional 45° - 180° on it for charging and you got a system storing 1kJ per shot with a 1m lever and 35kgf (so 70lbf) of preload. Built something to that effect as a teen and it is scarily effective. This as the added benefit of solving your awkward winding / tangling issue, you take care of that once since your displacement during charge and discharge will be small. It also allows your to go back to a twisted rope or rubber band bundle and still likely get decent results. You probably want a lot more than 180° of displacement, maybe 5-10 full rotations, so I suspect a bundle of stiff rubber will be best for you. Note that a twisted rope/rubber band spring is most efficient when it's much longer than thick, so you 2.2 Variable ratio gearing. Another muscle powered weapon also shows off a solution to that problem: modern bows! The pulleys at the end have variable radii so that your mechanical advantage from that always evens out the increase in force from the bow itself roughly following hooks law. You could try doing something similar by using variable radius gears that do one rotation, but if you want to get 500kg of car to 25mph that gear would need to handle a minimum of 50.000 Nm which is like a lot. It's probably possible to build it, but it'd be a huge hunk of steel. More likely you'd want something similar to a double clutch or CVT gearbox so you can switch gearing without decoupling. But thats like a huge modification to the car. Usage would also be weird with you having to shift down as you accelerate. Either way: bad news - Getting 500kg of car to 25mph is ~30kJ. The engine that belongs in that thing had like 300Nm going significantly above that might not be great for the transmission or drive shaft. At 300Nm getting to 30kJ is like 20 full rotations. That's with constant force. If you don't manage to get a constant force setup it'd be 40... I suspect more than 5ish is gonna be hard without getting tangle issues or the preload strategy not working. That's only 10-15mph - enough that it would be over the speed limit in a few places I guess... But if you're married to 25mph you probably need a custom car. Aluminum tubing instead of mild steel. No heavy diff or gearbox. Much closer to an actual rubber band car. If you manage to cut the weight in half that's half the rotations or half the torque your system needs to handle. I'd probably try to aim for 200Nm, 7 rotations inside the motor, and 250kg for the """car""" plus driver for a bit above 20mph if everything is pretty efficient.

Thank you Dave and all those who tolerate Joel's crazy antics!

thank you everyone and friends you are seriously amazing without the support, he would have gave up long ago but thanks to you this is all possible❤ you guys are insane thank you david and aaron, and i mean it

Thank you Aaron, David and Joel for making these amazing crazy ideas a reality

Thank you David and Aron

I really want to see more of this as there are more ways to harness the power of the spring. I think you might have to make an entirely custom chassis as that kit car is still quite heavy. By custom chassis I'm thinking just an empty rectangle with cross support.

This is so cool!!! I love your videos! I'm binging these, and thank you Aaron and David!

Thank you Aaron and David, this was a fun one. Random thought about the concept. There are “engines” that run from gravity, or even Mouse traps. Non elastic wrap around the drive shaft(string), and the lever does a fair amount of the work. Could you use webbing to do the wrap, and extend up to your bands? The bands could be wound up to the drive shaft, and they’d only be pulling in a linear mode. You could have an inadvertent energy loss as the band aren’t being stretched fully and equally?

Thank you Aaron and David. It makes for good suffering for Joel. 😂

Take the function of a mechanic wrist watch spring and use similar workings in the scale needed for that project and boom spring powered car.

Thank you Aaron and David! Also, condolences on having a mad scientist as a friend XD

🎉🎉With CNC machines 90% of the time you get random resets its static electricity. Ground all of the axis's properly, and there is a huge chance it will go away.

The concept is fine- the problem is the choice of car; build or use a lightweight go-cart and you'll be onto a winner.

Thank you Aaron and David for being enablers to Joel

this was so fun. thank you all

People say it's impossible to do something but if you try that impossible it can be possible 🙏😉

Hope to see more of this! Some ideas: - Pull the car with rubber bands between its front bumper and an anchored cable as a test - Turn each shaft into a row of U-Groove pulley bearings - Drag racing tires?

Thanks David and Aaron! I personally wouldn't get too much bigger of a spring after seeing car suspension videos 😂

THANKS DAVID AND AARON YOU GUYS ROCK.

I've been searching for a shop I can afford to save the car I love that's actively rotting to the ground; it's been almost a year now, of offering $800+ every month I can't afford just to get somewhere I can work on something and leave it for even a day. Can't begin to explain how important dudes like Aaron David are.. Envious of your friends man.

Xometry is great, but I used them one time at work and now I get a cold call every week to ask if I have projects for them. Thanks David and Aaron!!!!

If the cage had curved bars,making it force the bands to stay away from the sides, it may reduce friction.

Thanks Aaron and David for enabling joel antics but you had the correct principle but the wrong type of spring the pull back cars use flat coil torsion springs.

I am surprised you did not look into exactly how those pull back cars work. I am pretty sure they have a mechanism to stop the spring from rewinding as it goes in order to get full speed out of the car. So something like that plus honestly using a wind up rather than pull back mechanism would probobly make this work better.

My friend you NEED a round coil spring!! If you rethink your design a bit for the cage you could make a box around an industrial sized coil spring, and set it up with the shaft going directly through welded to the center flat bit and connect to the drive shaft, you can pull that suckered back and zoom! The round coil springs are what are in the toy car!!

A constant force spring may be a better alternative. You can get these springs in monster sizes. Thank you David and thank you Aaron!

Thank you all for your teamwork! It creates excellent content thats outrageously fun to conceptualize

Thanks David, Aaron, Quincy, John, other John and Charles!

Woah. This is a crazy build.

I had this same idea. I was thinking about a bunch of leaf springs run through a series of pulleys taking the load one or a few at a time before the next series kicks in. You can obviously turn the lever action into a rotary action use that for a governor. Winding it up would be the fun part but you could do it with a small engine and a hydro. Feel free to use any of it I have plenty of projects.

Thank you David, thank you Aaron.

I also work in garage doors. I have wanted to stick a garage door spring on a mouse trap car since I was in high school. This was next level. There has to be a way to make a garage door spring powered car.

Thank you Aaron and David for being enablers to Joel and his Antics 🤣🤣🤣

If you ever revisit the project, you could build the tension linearly and convert that to rotation by having it unwind a steel wire from the shaft. That way you could use the full potential of the rubber bands without having the issues of friction and uneven load.

Thank you David.... Thank you Aaron.

Your team is the dream team ❤️ thank you Aaron and David ❤️

this was awesome! i did feel the magic watching you all make a great toy.

the thing about those little cars is they had the weight of you pushing down in the drive tires while winding up. this kept them from breaking traction while winding up. i think you could build an external ratcheting system that stores energy in a leaf spring or something similar and have it attached to a really hi geared drive shaft. this, i believe, would create some powerful results

Thanks guys!!! This was am awesome project

Thank you David and Aaron! Y'all the MVPs!

You may be able to have the rod with the spring on it covered it foam or something similar, that can hold the spring straight when winding it, but has some give so when the spring gets tight, the foam can shrink.

Pro tip: Lube the pipes and put a slightly bigger tube (ID slightly bigger than the OD of the inner tubes) around it to make them turn, that way you'll lose way less efficiency via friction.

Thank you David and Aaron! Great video Joel

thank u aaron and david and quincy and john and

Thanks Aaron and David for helping make Joel's projects possible! Joel, you should take a look at constant force springs. I've designed a couple of CF spring mechanisms in the past and those are probably the way you want to go here. Also, you are going to need a LOT more spring force. CF springs really only produce linear motion. The best way I can think to implement this is to wrap a cable around a drum and use a CF spring to pull on that cable. In your birdcage design you could line each crossmember with short throw CF springs. Those spring will rotate around those crossbars. Then have them pointing inwards toward the rotating shaft, which you attach them to with a cable or perhaps a sheet of metal. Then when you wind up the car, it will pull out each of the CF springs towards the center loading all the springs while winding up the cables or sheets. Since you have so many crossmembers and your birdcage is so wide, you will be able to use far more CF springs than you'll probably need. Just find the right amount so that you can use the car's weight to wind it up and you'll be able to wind it through their entire length because of the constant force. Best of luck, can't wait to see your next video!

Thank you David, Thank you Aaron

love the video. Brings back some memories. Maybe multiple coils setup in a planetary gear configuration?

You could try it with a recoil spring like you get in a 2 stroke chainsaw pull start.

Thanks David, thanks Aaron

Thanks Aaron and David for helping with Joels spring shenanigans

You were so close with your endeavor just a little nudge in the right direction will make this project work! What mechanism also uses a coil spring to provide spinning motion? Watch springs

It might be a little dangerous but why not just use some large springs. Attach some nylon straps to the springs then have the nylon straps get pulled around the drive shaft.

Thank's everyone who helped with the projekt

damn good stuff! I used to have these plastic lanes you could connect up and then you would put these pullback cars into it and let it rip. played those to death with my brothers back then

Much respect to you David and Aaron 😂

Thank you Aaron and David for helping enable (and putting up with) Joel's shenanigans. XD

Maybe try bungie cords? They're designed for high tensile strength and durability.

why not use a spring like the one in a tape measure, and maybe have a way to hand tension it? Though that kinda defeats the purpose, it does let you get more tension.

Thank you David, thank you Aaron

Swapping out the torsion spring with oversized clock springs may help with both speed and distance

Thank you Aaron and David.

you needed to use a COILED LEAF SPRING!!!! (and use a quadbike cuz its lighter)