YOUR 3D Printed Airless Basketball Might Not Bounce 

It's actually impressive how much energy that white TPU can dissipate

Speaking as a librarian, I must say that Andrew's answer is deeply unsatisfying. Basically, all he said was "the different balls performed differently because they're different." I would have much preferred someone pointing out that the reason the TPU ball didn't bounce is because its more flexible material returned to the original shape fairly slowly, and so did not provide enough force to push the ball back up. Whilst the more rigid PLA returns to the original shape fairly quickly and thus pushes back against the floor hard enough to bounce. Well, up until the point that the energy involved exceeded the PLA part's structural strength and it just failed. (That last issue being why you don't make a real sword out of stainless steel.) This video did a good job of showing us all *what* happened, but failed to really get into the *why* it happened. On a side note, since no-one else has mentioned it, have you seen Slant3D's video about a 3d printed American football? They make the point that in the real world, if you're trying to transition to a new method of manufacture, you need to maintain user-experience expectations and so at least at first a 3d printed sportsball needs to not just *act* like the air-filled rubber ball but also *handle* and *feel* the same to the player.

It would be interesting to see more experiments. ABS, CF-nylon, PETG, and some of the more exotic materials that are available to the consumer printing community. Maybe some of the different resins (if there is a consumer resin printer big enough to do a full basketball)

Joel made a dead blow ball

😂🤣 wall slam might have been my favorite

I printed my ball in Flexable PLA. It bounces somewhere between a real basketball and a deflated basket ball.

What you want is a TPU with higher dynamic hardness (note not shore hardness, that’s indentation type hardness - we want rebound type) Rebound type or dynamic hardness is effectively a rough measure of a spring constant (realistically its the coefficient of resistution you derive from this testing data too like Andrew mentioned) Reason PLA bounces is because of this, but because its not not flexible enough to handle the loads (the UTS between layers is much lower than the typical UTS for PLA) PLA’s got quite a good young’s modulus, it’s a bit stronger than we typically associate it being But because of it being a ball, as it deforms as it compresses to rebound, the deformation effectively goes in every direction meaning it doesnt matter how you oreitnate it before bouncing (it’s also why they designed it like this for the material theyused, really good stress distribution, except you need the right properties for it to work properly) Am working on my university’s EV racecar project atm and I’ve been doing lot of materials research than I normally would for fun trying to address parasitic in a flanged insanely low friction bushing has been pretty cool (Iglidur Z was the material we’re using, it’s got effectrively the same friction coefficient as teflon but much better structural properties - though evenentually realised that low friction coeficcient has lead to slippage of the conical fastener that also was deforming the flange and have together caused the issue - now just gotta figure out how to fix it)

This was a really fun video to watch. Both as someone who 3D prints for a living, and who does STEAM workshops. The reason the TPU doesn't bounce as much is the same reason a mattress in a gym doesn't let you bounce much when you fall on it. The material properties absorbs the impact, dispersing the energy upwards as the impact progresses. It folds in on itself. So most of the energy is gone. Stiffness stores the energy for the bounce back. reason the PLA could bounce, sortoff. But the downside is stress fractures caused by storing all that energy in an unforgiving material. Just basic impact science. I also posted this on Uncle Jessies video

That was an excellent transition to Uncle Jessy. And of course we want to see the 3d printed baseball in a bating cage, just make sure to wear eye protection.

It would be interesting to see it printed in nylon. Or you could ask your friends at PCB Way to sls print you one …pretty it’s the way the original was made

This is a cool showcase of the different material properties. Love it!

I just finished printing an airless tennis ball as I saw this this morning. I used Flashforge Flexible PLA and it came out great. It bounces higher and for longer than an actual tennis ball. Just a PSA if you use this stuff, make sure you dry your filament first. It looks awful if you don't. Even fresh out of the bag, it didn't print great, at least not the small details of the hexagons on the ball. Dried it, and it works much better.

what a cool print!. keep up the nice content joel :)

Always love your excitement never change

Great video as always. Thank you 😊

Joel printed a 3d basketball And threw it on the ground! He's not gonna be a part of your system!

have you tried using two different types of filament in a dual nozzle 3d printer, use a flexible material and a rigid material. would that be possible or not

My adidas shoes are 3d printed soles with a lattice kinda similar but meant to be squishy for comfort. They have a sweet video with Adam savage explaining the material science behind it

It’s such a coincidence because just 5 minutes after this video was posted on this topic, Uncle Jessy posted a video on the exact same topic😂

You probably need to tension each of the "plates" by bending them. That could force some energy into the system/ball, so when it impacts a surface, it REALLY wants to push back, as opposed to dissipating the energy.

What software do you use to design it in order to print I really want to know.

Loved this format! Hoping Flexible PLA works well on these.

So what material was the Wilson ball printed with? It seems like it was not TPU.

Thank you Joel!!! Thank you for that video!!! I really needed something like thai

I'm wondering could it be possible to use TPU on the outside venues pla or ptg on the inside just a idea

4:27 that sound is crispy 👌🏼

Love hearing from Mr. Mayhall. If anyone ever wants to geek out and has the opportunity to talk with him about the science of Gloop, I highly recommend it. Dude is so smart and awesome to talk with. Keep up the collaboration Joel. ✋🏽

A great way to thank Andrew would be to order some 3D Gloop today!

This was fun. Thanks for having me over to check out the new space! Excited for things to come. 😊

Those things are better than airbags!!!! There's gotta be a use for something that dissipates that much energy!!!

I have been wondering if it would be possible to print this in multi-material, with something like a PETG lattice core, with a TPU external wall or two to prevent breaking. Might be a good XL print to use those toolheads!

I wonder if you could print the infill in a rigid material then print the exterior perimeters in a flexible material and combine the properties of both.

I bought some Atraxia Art flexible PLA and printed an airless baseball that bounces really good and is flexible yet firm, If you use the Flexible PLA, It might just work.

1:08 your face experiencing an eclipse

Hi Joel! I just relised that PCBWay also offers a 3D printing service. Since they sponsored this video, You could have asked them for a ball printed from nylon using SLS method. That would have definitely bounce, and perhaps even wouldn't crack? Printing it in MSLA printer using some tough resin might provide some success too. ;-)

Hear me out: dual extruder so you print a super PLA+ ball nesting perfectly inside of a TPU ball. Maybe the two filaments will offset one another's weaknesses so you get the perfect ball.

Joel! How did you do the Timelapse with the XL? Love the video!

I recently read something that said they used a TPC type filament. I managed to grab a role from matter hackers before they discontinued it, unfortunately it is 3mm in thickness so I will have to wait to test it until I can assemble a new hotend.

Also which Polyflex shore hardness did you use?

Hey Joel! If You want it to bounce - print from PEBA material. It has probably the best energy return value out of all flexible filaments. But its expensive :( Good thing is - its freaking impossible to break that material :D

What about shell make in pla and interior in tpu ... Or do like 2 mm one then 2mm second and do it in alternate way.

can you make one using the Bambu printer or a multiple filament where the interior is something hard and strong like Abs and the outer a rubber material?

Originally commented this on Uncle Jessy's video, now it ended up here 🤷: A few years ago I was looking into getting a dual color printer, and the best one for my budget had one extruder, but 2 PTFE tubes/filament going into the one extruder. Kinda like the AMS but different and way older. So my theory, through lots of g code editing, is to acquire a machine like this, for example, the Geeetech a20m (if it still exists), and with these printers, you can actually combine filaments to make different colors. Ex. white+black at same flow speed=grey. This is usually used for gradients from one color to another in prints, it might not work on a whole print. SO... You use PLA or possibly PETG for the first filament, and some 85a or 95a (prob. 95) TPU for the second filament. If the settings are correct, now (theoretically) you have a custom PLA TPU mix, that can be customized to whatever hardness you want through changing what filament is used more. This is 100% a theory, i have never owned a printer like this, plus they are probably hard to find. Just an idea.

watched Uncle Jessy's video right before yours. His had more luck bouncing, yours had more science, both had a great use of 3d Gloop! Awesome!

Do you think Armadillo 75D tpu would perform better because it is stiffer?

I think that PLA ball could work better with a better means of distributing the load stress, similar to that 'supernatural' infill pattern RMIT University came up with for titanium recently. Perhaps internal struts across the circumference of the ball in a star pattern? Kinda like the spokes of bicycle wheels but in a ball shape rather than a cylinder.

I want to see so many types of sports balls tried. There is a 3D printed football design!

Great video Mr Telling! Try one more with the almost indestructible Ataraxia flexible PLA. Thanks

Wilson over here inventing the $2500 wiffle basketball.

id say you need a filament thats not flexible per say but strong rigid material that can bend enough but instantly form back under its own tensile strength to bounce it back like a real ball does (the air in a normal ball makes it try to go back to shape because of air displacement)

Just out of curiosity. Why not flexible pla?

What if the interior of the ball had a sparse honeycomb lattice so it could evenly transfer that energy so the force isn't traveling along the circumference? Its impossible to injection mold, but not hard to 3d print.

I would love to see the batting cage tests :) .

I would try esun PLA ST. Has an amazing elongation compared to normal PLA so it should perform well

I printed one and im glad it going splat wasnt just my result haha. I actually would love to get a collection of different materials and see how they print and compare the results

Perhaps a higher durometer flexible is needed. When you boil it down a basketball, volleyball, etc is basically an air spring.

As cool as the concept of an airless basketball may be, I do have a lot of questions about how it would perform, even if it could survive the stress of repeated impacts without the support of pressurized air. What would the air dynamics be like? Wouln't that amount of surface area trap a lot more dirt, deadskin, and sweat, especially on the inside where it would affect its performance even more?

Whatever you do DO NOT ask Andrew about TPU Gloop. He gets mad at you if you ask too many times 😭

was asking myself this two days ago, not even a joke lol I remembered seeing that super expensive one that bounces normally and wondered if I could find a TPU that would work.

This is the most aggressive I've ever seen Joel... Good times. Once I started seeing people printing in PLA and PETG, I became concerned. Those will bounce... until they break. Which means you get multi-day, 1kg single use... and then it's done. So if showing off, use whatever you want. But someone is going to want to try to bounce it... and then the problems arise. ABS is probably in the same boat, CF-anything is gonna make it MORE brittle (and cost a pretty penny). Nylons I have the least experience with so how well it does... would love to see a video of it. TPU is a much better choice for most people, but obviously it's too soft. Or is it? This issue is a product of our own creation. People went "if I want something solid, PLA/PETG/ABS. If I want something not solid, TPU/TPE". and for TPU/TPE, they wanted softer and softer. I haven't tried it yet, but I plan to try NinjaTek Armadillo which is 75D vs. the 90-95A that most TPU is. I have printed with it before and know it basically is indestructible BUT still bends and flexes and have thrown models at the ground and they bound back. So hoping for the best.

Joel nice looking prints. maybe infill with pla + and walls with tpu

its strange how all of this leading 3D printing channels didn't even try several types of TPU materials. its like they are paid to deliberatly do that to promote that origina Wilson Airless Basketball

I'm curious on why you didn't use different material for supports?

3D printed baseball testing would be amazing

What if you print the outer perimeter with tpu and the infill with pla+? You can do it with the Prusa XL

Wonder how well a variable flexibility filament, printed at a low temp would work.

Joel... use the xl's magic. Print a PLA ball coated in TPU. Combine materials.

Ha, so nice you put BASEketball scene in there 😅

from what I understand about elasticity, there might be a material that is really bouncy, under the right conditions. or in other words: you need to make an airless basketball out of 3d-printed steel.

2:00 When you order your $2500 airless basketball from Wish

Much like the basketball, I'm stuck bouncing back and forth between Uncle Jessie's video and Joel's video.

Would love to see one of these pronted out of polypropylene, much tougher than PLA and much stiffer than TPU

How about TPU 98A? OR carbon filled TPU? Would probably be best printed with powder SLS either way.

How about PETG ? its not as brittle as PLA...

what if you did a 2-in-1 PLA + TPU? has anyone ever tried mixing the two?

can you share OrcaSlicer profile config files for TPU?

I saw 3D printed balls the other day under some guy's truck. They were bouncing just fine.

So the big question is does a filament exist that can mimic the material used by Wilson.

Well those balls would make good dodge balls now

There are different hardness levels of TPU. I wonder if more or less firm would help.

Looks like Luke Skywalker got to that white PLA ball.

missed opportunity to show off PLA supports for TPU on the Prusa XL

i thought you were gonna try PETG, it was my first choice as a mix between PLA and Flex. Maybe Nylon would be even better.

Probably need to print it in PETG to keep it together,.

I think this stream holds the highest count for the amounts of times 'Balls' are mentioned. 😊

You may not be able to dribble with that ball, but you can drool! LOL High-5!

new crash protection material

Wow look ma I was on a Joel show! High five 🖐️

i think u should try chinchilia or TPE

Well at least we know it's great for shock absorption!

So FDM is just a bad match for this. My guess is that they used SLS. Material wise you want a nylon. That is going to give the right ratio of ductility to hardness. Lastly, the structure is wrong you need a second layer to act similar to the bladder inside the ball to give the structure the right characteristics Basically give it more bounce.

Try it with PP. Did a tennis ball & the bounce was great.

Rubbery things aren't actually that bouncy. Steel ball bearings are actually very bouncy. It's not about using squishy material, but material with low internal dissipation, which are actually ususally very stiff. Something stiff like the PLA, but more durable, like a nylon or CF-nylon would probably be ideal. SLS nylon would probably be ideal, and may be what the real ball is made of.

What about one of the FPLA Flexible PLA filaments??

I think the TPU balls could spontaneously form black holes.

Why haven't you tried PETG?

What impressed me! The first ball was not destroyed

Can you combine PLA and TPU in one ball?

Batting Cage 🤘🤘

cool video but it felt incomplete. It was basically "this is why it does not work in TPU or PLA." and not "Lets see how close we can get." I would have liked to see a video also covering "let's see what other filaments would perform better" and "What kind of properties from a filament do we need that might not exist"?