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GooneyBird

Scale details, sure; but what about scale movement?

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There are a lot of amazing scale builds here, and on the internet. In static photos, sometimes these cannot be distinguished from the real thing with their amazing realism and attention to detail. But as soon as they start moving the illusion is broken. They're clearly too light for what they are, bouncing up and down far too eagerly with every tiny bump. In slow-motion video (Heyoo Mateo!) this isn't too bad, but once you start seeing them in real-life, the lack of body movement compared to the suspension travel is jarring and pulls you out of the illusion of looking at a real car. Even scale semi-trucks, which are fairly heavy for their size, have the issue of suspension that's too hard, and a little underdampened.  

Enter technology! With an Arduino, micro-servos and a LOT of 3D-printing, you can have a car that moves like the real thing. Especially if the 1:1 car weighs something like 2500kg. 

 Also, I spy TT01 steering knuckles and DT02/03 front wheels with custom hubcaps. Tamiya pride!

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Times like this I wish there were a 'love' button.

That is amazing! B)

Do you have more info on it?

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I was talking about this in bigrig terms at a local truck meet at the weekend.  A few years back someone was sharing videos of an air-suspended truck cab that moved around on servos over rough terrain.  It looked pretty clever, but IMO was way over-exaggerated and looked a bit silly.  Apparently now there are kits available that you can install yourself.

My friend was considering making one, and we both came up with the same idea at the same time: drift gyro!  With a tuneable gyro (specifically with a tuneable delay) and some reversing servo mixers, you could make a cab lean or bounce in response to chassis movement.  In fact you could make it continue to bounce by mounting the gyro on the moving cab.  I'm sure you could get some really interesting feeback if you had it tuned right.  Just yesterday I was setting up a new servo for my WT01 build and I hooked it up to a GT5 receiver.  I centred the servo, at which point it started glitching - wobbling back and forth and not finding a centre point.  I thought it was yet another duff receiver / servo / brownout problem, but then I realised what it was:

GT5 receivers have built-in gyros.  Last time I use the receiver I'd switched the gyro on via the Tx, and had forgotten to switch it off again.  The receiver and servo were lying loose on the workbench, connected by standard servo cables.  When the servo rotated, the shaft went one way and the loose body (neatly obeying Newton's laws) went the other.  This pulled on the lead, which pulled the Rx.  The gyro activated and told the servo to go the other way, which had the opposite action and pushed the Rx the other way, thus reversing the gyro's output.  I expect it would have happily twitched back and forth until the battery ran out or the servo overheated.

If you had sensors to read the surface of the road in front of the tyres - as well as the forces acting on the chassis - you could build in fully reactive suspension movement and body roll that emulates 1:1 response.  Of course the chassis must still respond to the forces acting on it in 1:10 scale too - I don't think you could build a racing car that would rock and roll like a 1:1 and still stick to the racetrack properly because the 'reactive' suspension movements would be out of sync with the forces acting.  I'm no suspension expert or newtonian physicist but that's my gut feeling.  Case in point in the video - that car drifts surprisingly well, but there are moments when it seems to suddenly break free which probably coincides with the servos moving the heavy chassis and unloading the tyres.  At no point does the vid show the car responding to a physical push down on the body - my gut is that the suspension is rigid, which means it won't work at all on a rough surface.  But I may be entirely wrong - if there are dampers to soak up and stop the initial shock, the inertia transferred into the chassis will trigger the bounce.

The other thing to remember in terms of 1:10 suspension response is the world is 10 times bigger.  What looks like a tiny ripple in a carpet racetrack is a speedbump to a 1:10 touring car.  But because they're so much lighter they can withstand an impact that would push the struts through the bonnet of a 1:1 car.  The laws of physics are the same no matter what size you are (provided you're above atomic scale) but they don't necessarily translate to the same response - hence why we can do things with 1:10 cars that you could never do with 1:1, but also why they never look quite right when scaled up.  Videoing at a high frame rate is the best trade-off because you're allowing the suspension to work at the scale and rate it needs to work at but rendering it to the viewer at the rate they are accustomed to.

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You want "realistic action" go play with Large Scale aka 1/4 or 1/5th scale...! 

Or better still go 1:1 and drive in it yourself! :) 

 

For a compete 900degree swerve away from realistic... try HyperRealistic bordering on Surrealism from our good fella Danny Huynh:

 

 

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I absolutely love Danny Huynh.  This is exactly what I wanted to do when I got back into RC 15 years ago, but a distinct lack of talent, determination and perseverance led to the somewhat underwhelming showroom that I currently own.  Still, we must thank Mr Huynh for showing us what is possible and for pushing the envelope, so that we may be towed along in its wake :)

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9 hours ago, GooneyBird said:

Enter technology! With an Arduino, micro-servos and a LOT of 3D-printing, you can have a car that moves like the real thing. Especially if the 1:1 car weighs something like 2500kg. 

 Also, I spy TT01 steering knuckles and DT02/03 front wheels with custom hubcaps. Tamiya pride!

That

 

 

 

 

 

is very impressive

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This is why I like XR311. 

Well before ESC, let alone Ardruino, Tamiya had made suspensions supple.  With torsion bars!  

 

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Thanks for posting ‘Danny Huynh’ , I happen to stubble across one of creations on YouTube a couple of years ago by chance on holiday but could never find it again until now, and it’s been driving me nuts!!! 👍🏻

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4 hours ago, Re-Bugged said:

Thanks for posting ‘Danny Huynh’ , I happen to stubble across one of creations on YouTube a couple of years ago by chance on holiday but could never find it again until now, and it’s been driving me nuts!!! 👍🏻

He's possibly more well known as "dPhotographer", he does some great camera work too.

i have a love/hate with Danny :P love his work but many yrs ago I let him buy my limited edition golden TA05VDF still mint in box when I shipped it out. He also bought a limited edition golden TB03VDS. 

If you watch many of his earlier models you might notice golden alloy parts :o:wacko::blink: and whenever I spot that I shed a tear... :(:(:(

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I have always had this problem with the Toyota hilux/ bruiser etc chassis vehicle's they all look amazing from stock build and in the old tamiya videos when they are bouncing down the sand dunes in slow motion and they go to another level when the scale guys get there hands on them:wub:...........until you see them move:wacko:!, my first bruiser I was bursting with excitement on its arrival and building the beast! I took ages to complete it so it would look as amazing as i could get it then the big day arrived its first fully built run and that's when it all kinda unfolded as it bounced around the garden like something off the magic roundabout (for those who remember that?) So it was a case of absolutely stunning looking truck but let's just put it on the shelf and look at it from now on:unsure: and when people ask to look at it just show them on the display stand how it can change gear and go from 2wd-4wd!

images.jpeg-1.jpg

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When the TA01 touring cars first began to show up, what drew me to them (in photos, at least) was that they leaned in turns and generally appeared to body roll more like a real, road-going car. I'll never be an on-road guy, but it at least grabbed my interest vs. the previous pan cars which all darted quickly to and fro somewhat unnaturally like an F1 car.

@moffman summed my feelings up perfectly. Scale dynamics (or lack thereof) is one component that keeps me away from scale crawling. In scale crawling, the vehicles move slowly, giving your eye plenty of time to take in all the scale details. Their movements wreak the illusion for me. The steering moves far more rapidly and effortlessly than a fullsize. Perhaps its being electrically powered (vs internal combustion) and/or the light weight that effects their movement and throttle response. When encountering tougher obstacles, they tend to pause (as motor power is gradually increased in an attempt to clear the obstacle) and then suddenly, quickly (and jerkily) hop over the offending impedance. The weight ratio and torque curve differences between scale and 1:1 change the whole timing and dynamics of the situation. 

As discussed in previous topics,  RC is in a tough spot, realistically. They move far faster than scale speed in cases outside of crawling, yet at scale speed, most would consider them boring. This is why I'm drawn the buggies and monster trucks. Everything is bigger and more exaggerated. Even at the incredibly rapid scale speeds they're moving at, the bigger tires, shocks, suspension movements, etc. can all be picked up by our eyes leading to a dynamic, visually exciting experience for me at least. I could never get into slot cars as they're simply too fast for me to take in.  Just my 2 cents.  

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The bruier is pretty darn accurate, the tire are a little exagerted but everything esle is pretty scale.

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