Fluffy, an oversized proof of concept

[Attika]

Hello there,

it's been a while....

I wasn't entirely inactiv in the last couple of years, but I had a technical difficulty to make videos. Without videos there's no point to post anything, so there it is,a big chunk of can't do attitude...

However it has changed. The subject of this topic is on an exhibition now and I was forced to overcome my lazyness and make that camera roll again.

To the subject:

 

How did I get this low?

I've bought 2 sets of this Audis back in the day as I've found it being a good value for money as a partpack. As a sideproduct I had enough of the curvey panels to get physical on an old idea, the barrel like structure you see on the thumbnail above.

Luckily my past granted me an unlimited supply on connectors.

As long as it existed only in my head, I was quite sure it is too flimsy and fragile to bare any load, let alone to coop with the centrifugal force that comes with the rolling motion. While rolling around the empty barrel on my desk I figured I could use a somewhat symmetric structure to apply an inward tension on the barrel and that's gonna keep it from falling apart. The fact that the barrel made out of 16 panels made it kinda obvious what symmetry should I use. I put my bet on a 4 spoke solution. The barrel would give a 15.5x15.5 stud square to work with, so I've used a 15x15 structure to reach that inward tension. It is well within the reversible flex of abs, yet enough to keep the circle from pulling apart The next challenge was the attachment of the wheelhub. There is an interlocking frame that holds the sprocket wheel in the center of it....

 And so to prove the concept, I had to build a whole chassis around it.

For those of you who can benefit from a studio file, here it is: https://drive.google.com/file/d/1uX-avOl3x6DPfGcx_IF1nKzRtAwWqvu6/view?usp=sharing

As a sidenote, the io model is a simplified version when it comes to the chaos I've built in the mid section of the frame to avoid the twisting of it. Also I took advantage on the natural flex of the connector body which could not be replicated in the rigid studio enviroment. But I can assure you, no parts were harmed.  

Some of the data:

It is about 70 cm long and 50ish wide, has the ready to run mass of 2.7kg. Uses 4 buwizz motors to drive, a PU L motor to steer and 2 buwizz 3units to get the sparks. Originally I've built it using the slow outputs but on the 2nd testrun I had to try the fast outputs on the motors and it took it like a champ. Although it altered the driveshaft geometry slightly, it had next to no effect on the practical usage. I can't emphasise enough that this car is only a tool to prove the concept of the wheel here.

To keep the buwizz units from shuting down, the max output is reduced to 92 percent.  This setup gave me fun to play dinamics and a very generous 10 minute + runtime. Way more on both than what I've expected at the begining.

The chassis I suppose speeks for itself, nothing out of the ordinary. The lower wishbones have a wider base towards the chassis to deal with the frontal forces. No drivetrain -no loss of efficiency on gears.

One thing to mention to fellow builders:

I had so much room to work with inside the wheel, when I was building the front suspension, I couldn't stop smiling how effortless to do a "proper job". Meaning caster, camber, and ackermann geometry...

Nothing else really comes into my mind, but I'm sitting on this for a half a year now,so I might just be numb about otherwise important details. I'm happy to answer your further questions.

Thanks for your attention and feel free to give a honest feedback. My psychiatrist prepared me for situations like this. 

 

PS: If you find the panels on the wheels looking suspicious, that's the tape I applied on them to save them from the scratches (as much as possible).

 

 

 

 

[Shiva]

Hah! Nice!

[Aurorasaurus]

I love it! Those custom wheels are amazing, do you know their diameter? It's good to see you back making videos, I hope it continues!

[2GodBDGlory]

That's a pretty fun model! The tubular bodywork is pretty cool-looking too

[dr_spock]

It's so fluffy.  Nice work. 

[Jurss]

You reinvented the wheel.

[Attika]

10 hours ago, Shiva said:

Hah! Nice!

Hah! Thx! 

 

8 hours ago, Aurorasaurus said:

I love it! Those custom wheels are amazing, do you know their diameter?

Sure. I remember measuring some 18 cm (the model is on the AMTS show, away from me) , but the studio model info says 20.3. Being abarrel shape can explain this x-file I suppose.

 

8 hours ago, Aurorasaurus said:

 I hope it continues!

Then there are two of  us now...

 

55 minutes ago, Jurss said:

You reinvented the wheel.

I was trying to avoid claiming anything like this, as it felt so obvious after the idea appeared, I was sure it is already out there somewhere. I still hold this belief..

 

6 hours ago, dr_spock said:

It's so fluffy.  Nice work. 

Thanks Sir. 

[m00se]

I like these kinds of builds that show a lot of "out of the box" thinking. Very original work.

[Lipko]

I saw it ín real life. It's brutal, yet running very smoothly and gently. Like some Boston Dynamics stuff. My mind was blown.

[NoEXIST]

It's really nice to see you're back! And this thing is wild! I love the curves and how it performs. It drives very nicely knowing that there are just 2 bw3 units and 4 motors!

[Carsten Svendsen]

I just LOVE the framework. There's just something beautiful about the old school way of doing framework. And the wheels are cool too, though, the main part of this build. 

[aeh5040]

This is brilliant! Elephant simplicity, and at the same time it's clear how much thought has gone in to it.

Do you happen to have some static pictures of the wheels? The internal structure is not obvious to me.

[Attika]

On 3/23/2024 at 12:34 PM, m00se said:

I like these kinds of builds that show a lot of "out of the box" thinking. Very original work.

Indeed,it was hard to find a fitting box for trasporting it to and from the exhibition... 

On 3/23/2024 at 7:53 PM, Lipko said:

I saw it ín real life. It's brutal, yet running very smoothly and gently. Like some Boston Dynamics stuff. My mind was blown.

Heart warming worrds from a living legend... I am humbled. 

 

14 hours ago, NoEXIST said:

It's really nice to see you're back! And this thing is wild! I love the curves and how it performs. It drives very nicely knowing that there are just 2 bw3 units and 4 motors!

 

12 hours ago, Carsten Svendsen said:

I just LOVE the framework. There's just something beautiful about the old school way of doing framework. And the wheels are cool too, though, the main part of this build. 

10 hours ago, aeh5040 said:

This is brilliant! Elephant simplicity,

Elephant?  If that was the autocorrect, it really knows it's ways

10 hours ago, aeh5040 said:

Do you happen to have some static pictures of the wheels? The internal structure is not obvious to me.

it is all black on the real one, so I made a rainbow render, hope it helps.

Edited March 25 by Attika
Found my bricksafe account

[Aurorasaurus]

2 hours ago, Attika said:

it is all black on the real one, so I made a rainbow render, hope it helps.

You're a madman, and I love it. 11x15 frames inside the wheels is just ridiculous. Did your wheels ever come off?

[aeh5040]

4 hours ago, Attika said:

Elephant?  If that was the autocorrect, it really knows it's ways

it is all black on the real one, so I made a rainbow render, hope it helps.

Oops 

Many thanks for the render! I find it interesting that this is enough to hold it together...

Edited March 25 by aeh5040

[damian_kane_iv]

Very impressive indeed! Did you ever consider adding those small rubber axle connectors or pins/pegs to increase traction on the wheels?

[Attika]

7 hours ago, Aurorasaurus said:

You're a madman, and I love it.

I'm busted. 

7 hours ago, Aurorasaurus said:

 Did your wheels ever come off?

Yep, long time ago, but Fluffy never had this problem. The only care it requires is on the side of the body. A connector slips out every now and then. If you watch the video,  on some footage its visible. Once you see it, you can't unsee it.  It has a cumulative 2-2.5 hours in it, so in lego therms I can call that a long range test period. One thing is sure, it doesn't like snow. Took it out this winter and in 5 second shoved all the snow on the top of the buwizz units.

6 hours ago, aeh5040 said:

Oops 

 I find it interesting that this is enough to hold it together...

So did I....  The only way to "break" the wheels if I hit a curb, wall, or anything biggy with high speed. Hence there is no off road footage (Imean rocks and bigger obsticles), the grassland is its real home. A golf course would be paradise.

3 hours ago, damian_kane_iv said:

Very impressive indeed! Did you ever consider adding those small rubber axle connectors or pins/pegs to increase traction on the wheels?

Yes. And decided not to do. As you see on the video, on grass it has pretty good traction, but I'm sure due to the size and speed, if there was any more traction, all the sideway forces would come down to the wheelhub. This way it can slip those lateral forces out and no bricks get harmed.

[gyenesvi]

Not sure what all the fluff talk is about, it's no big deal, I've just seen something like this during the weekend running around like a puppy  

But seriously, crazy idea and great engineering, well done! And keep them coming :)

[N1K0L4]

Good idea, I especially like the body with it's organic shape. Great job with that! Have you had other versions of that wheel before this one?

Also, I'm Nikola from last year's BuWizz camp. It was nice meeting you there and I hope I'll see you this year too.

Anyways, I wanted to say something. If size really matters, how did I then manage to not be near last place in the offroad competition ob BuWizz camp with my Mini Tracked Vehicle ( https://rebrickable.com/mocs/MOC-165686/N1K0L4/mini-tracked-vehicle/ )? I was at least 3 times smaller then everyone!

Have a great day ;)

Edited April 7 by N1K0L4

[Attika]

On 3/25/2024 at 8:13 PM, gyenesvi said:

Not sure what all the fluff talk is about, it's no big deal, I've just seen something like this during the weekend running around like a puppy  

But seriously, crazy idea and great engineering, well done! And keep them coming :)

 

12 hours ago, N1K0L4 said:

Good idea, I especially like the body with it's organic shape. Great job with that! Have you had other versions of that wheel before this one?

Hi Nikola, This is the only version of the wheel. I've built it, it did work, so there wasn't an urge to further optimise it. 

12 hours ago, N1K0L4 said:

If size really matters, how did I then manage to not be near last place in the offroad competition ob BuWizz camp with my Mini Tracked Vehicle ( https://rebrickable.com/mocs/MOC-165686/N1K0L4/mini-tracked-vehicle/ )? I was at least 3 times smaller then everyone!

Strange question. There is 3 different type of answers to that comes into my mind:

1 Smartypants type: The bigger the wheel, the larger obsticle it can clear. 

2 Arrogant type: Cos u r a genius and we aren't... 

3 statistical typeThe last places were for people like me, who melted the axles b4 get through the finish line. 

And answering your deleted question: It is nearly 3 kg of abs with substantial speed. I feel like the current setup is very near to he limit where the material and connections still can handle the physics of it. More motors, more buwizzes make it heavier and probably faster, increasing the momentum. And I'm sure that is the point where parts start to break.