In this video, I build my own Drag Reduction System (DRS) for my RC car. DRS is commonly used in formula 1 where it works great. But can DRS work on a small Traxxas RC Car?
man this sort of stuff could change the landscape of competitive RC racing. how cool would it be to see an openly engineered RC world championship? custom bodies, chassis, aerofoils etc.
Great to see you back, would love an indepth video on thermals at some point, similar to your first (or early) video. I notice Arrma are fitting heatsinks and fans to some of their range out of the box these days.
I love this channel. I'm not this smart, so I have to get by on my willingness to break my cars and just lean into being the idiot I am. If I was smart like this guy, I would probably be attempting similar AWESOME stuff like this. Great video! I hope you get a million subs soon.
That's awesome. You sacrificed the RC car for science. I can't believe how quickly the car generated enough downforce to lift the front end like that. How fast do you think you were going? I think it's a lot harder to regulate aero downforce at the RC car scale. After watching your video, I ran my RC car thru some CFD simulations and my car will launch into the air like that with ~4 degrees of pitch change, and I have a giant opening behind the front wing for air flow not a flat floor. 4 degrees of pitch is huge for a full size car but for an RC car this is just a small bump around 20mm. I don't know if you found this but multi-element wings tend to be less pitch sensitive, which probably made your situation worse because as the car tilted the rear wing was still making a good portion of it's downforce.
I was probably going 60 mph so not even close to top speed. And yeah the multielement rear wing is running the equivalent of a really high angle of attack that would stall a normal wing. It would fully obstruct the flow to the wing before you could actually make it a neutral angle of attack. Short wheel bases are a killer.
Curious that you saw such impressive results with a simple scaling without taking into consideration the Reynolds number effect that downscaling would impart. Perhaps it was somewhat offset by the inclusion of the 3rd wing. Fascinating video of the wing flexing under aerodynamic load! Seems that a variable front downforce device would prove to be very valuable.
These wing elements were actually designed in a CFD based program for multielement wings at the proper scale, so there was no Reynolds number scaling required. The elements are a modified NACA 9415 to improve manufacturability and performance at this scale. I definitely need to fix the front downforce in a better way.
Easy workaround for the flipping... Set the actuator to the "no downforce" position by default, then have it go "full downforce" if either brakes or steering is inputted. Either that or the even simpler route Set the actuator to "full downforce" at all times except when the throttle is pressed have it set to "no downforce"
Good ideas. I think when I do my next active aero build I will do a really sophisticated system that tries to balance front and rear aero loads using load cells.
@@EngineeringAfterHours You can even try using a gyro to actuate a quirky all directional aero wing. I think its called the "centripetal wing" or something... look up videos on it its pretty cool. Zenvo TSR-S’s Centripetal Wing. You can start off simple by hooking it to the steering then stepping it up after proof of concept with a gyro. Given how much downforce the test one made it should have a MASSIVE effect!
But anyway, to be on topic to the video, have you explored unsprung aero? That should quickly solve your squatting problem, plus it lets you run softer suspension all around for better mechanical grip at low speeds. Also, RIP GT car body and aero. Thanks for the video on DRS.
Really cool!... another great video. I've often wondered if a front splitter with this tech, attatched to a gyro would keep the front from lifiting if set right..?? Would create more downforce if car was constantly trying to lift up but if normaly level and just fighting the odd bump, maybe it would be good.... also if working with the back one, so had extra downfoce all around for coners and none for the staights... just a thought but I'm no expert.. independant sides would be another step so could add downforce to the inside through corners..
Nice. Have you considered to try something similar to the active aero like the Pagani Huayra BC with both front and rear aero flaps that also help turning.
Absolutely. I asked chatGPT to write me a code that will take input from a load cell and adjust the servo accordingly. That also allows me to keep aero balanced front to rear.
On such a small light weight vehicle, wouldnt simply adding ballast weight result in the same traction advantage but without the added aero drag or a wing?
I've done the ground effects before, I may revisit that. I would really like to play with something like an aircraft catapult for an rc car to get killer acceleration.
I knew I needed the rotation of the drs elements would be less than total servo angle. I also had a smaller level arm for the elements than the servo horn. So that mean 1 degree of servo movements made over 1 degree of wing movement, and I needed less than 45 degrees total. From there, I just changed the servo end points on the remote to limit how far it could travel.
Thanks 🙌,Actually i am trying to do in my project is when my car's acceleration is more than 50% of total, the drs will activate, and when brakes are applied, instantly the flap would close. Just trying to figure out how do i implement this using a servo.Can you give me some tips ?
@harshdoshi4800 I would use an arduino to take the pwm signal and convert it for your needs. So basically from neutral to half throttle, it tells the servo to stay put, from 50% throttle to 100%, scale to full open, and on the braking side...just use throttle as normal.
Unfortunately the ride height was about as low as it can be and still be drivable. Any lower and it catches on every little bump and seam in the road. This just shows how dangerous underbody aero can be on cars with such a short wheel base. The pitch change over a small bump is multiple degrees. Whereas with long wheelbase cars, it's negligible.
>24fps >Filming a small, fast moving object **pukes** Please at least use 30. I can give you camera settings to make any frame rate for any type of shot on most cameras look amazing. The main thing you gotta do is ignore the 180-degree rule and instead select a shutter speed in the 1/40th to 1/60th of a second range, and set shutter priority mode if you use auto exposure. You may need to buy an ND filter in order to shoot outdoors in bright situations after locking down your shutter speed like this, in which case, if you only want to spend money on ONE, get an ND16 filter, but if you buy TWO get an ND8 and an ND32. Also, avoid decimal framerates (23.976/.98, 29.97, 59.94) and instead use full frame rates, or at least never get them mixed up in post without properly re-encoding decimal to full. Lastly, avoid non-intra-frame codecs and instead use only all-intra-frame codecs such as ProRes or if you use a Sony camera XAVC S-I not plain S or X. They preserve motion accuracy better AND edit faster/easier on your PC.
man this sort of stuff could change the landscape of competitive RC racing. how cool would it be to see an openly engineered RC world championship? custom bodies, chassis, aerofoils etc.
I would love to see that. It would also make it pretty easy to double as an autonomous racing challenge.
Should have asked Mark Webber to guest star as your test driver
Hahaha...I missed this one the other day and am glad I just saw it. True fans of the sport are much appreciated!
Great to see you back, would love an indepth video on thermals at some point, similar to your first (or early) video. I notice Arrma are fitting heatsinks and fans to some of their range out of the box these days.
Arrma beats traxxas on the thermal analysis side for sure. I'll try to think of a way to work some thermal stuff in.
That's pretty awesome
I love this channel. I'm not this smart, so I have to get by on my willingness to break my cars and just lean into being the idiot I am. If I was smart like this guy, I would probably be attempting similar AWESOME stuff like this. Great video! I hope you get a million subs soon.
Thanks for the kind words! I prefer to think of it as being "specialized" more so than smart.
@@EngineeringAfterHours it's awesome stuff!
That's awesome. You sacrificed the RC car for science. I can't believe how quickly the car generated enough downforce to lift the front end like that. How fast do you think you were going?
I think it's a lot harder to regulate aero downforce at the RC car scale. After watching your video, I ran my RC car thru some CFD simulations and my car will launch into the air like that with ~4 degrees of pitch change, and I have a giant opening behind the front wing for air flow not a flat floor. 4 degrees of pitch is huge for a full size car but for an RC car this is just a small bump around 20mm.
I don't know if you found this but multi-element wings tend to be less pitch sensitive, which probably made your situation worse because as the car tilted the rear wing was still making a good portion of it's downforce.
I was probably going 60 mph so not even close to top speed.
And yeah the multielement rear wing is running the equivalent of a really high angle of attack that would stall a normal wing. It would fully obstruct the flow to the wing before you could actually make it a neutral angle of attack.
Short wheel bases are a killer.
And just when I thought RUclips betrayed me.
You came to my rescue.
You should have way more subs for this level on content
Thank you! Someday I will figure youtube out...in the meantime...if you have tips please feel free to share.
Curious that you saw such impressive results with a simple scaling without taking into consideration the Reynolds number effect that downscaling would impart. Perhaps it was somewhat offset by the inclusion of the 3rd wing. Fascinating video of the wing flexing under aerodynamic load! Seems that a variable front downforce device would prove to be very valuable.
These wing elements were actually designed in a CFD based program for multielement wings at the proper scale, so there was no Reynolds number scaling required.
The elements are a modified NACA 9415 to improve manufacturability and performance at this scale.
I definitely need to fix the front downforce in a better way.
I'm so glad you're back!
Thanks! Hoping for some fun projects this year.
Easy workaround for the flipping...
Set the actuator to the "no downforce" position by default, then have it go "full downforce" if either brakes or steering is inputted.
Either that or the even simpler route
Set the actuator to "full downforce" at all times except when the throttle is pressed have it set to "no downforce"
Good ideas. I think when I do my next active aero build I will do a really sophisticated system that tries to balance front and rear aero loads using load cells.
@@EngineeringAfterHours You can even try using a gyro to actuate a quirky all directional aero wing.
I think its called the "centripetal wing" or something... look up videos on it its pretty cool. Zenvo TSR-S’s Centripetal Wing.
You can start off simple by hooking it to the steering then stepping it up after proof of concept with a gyro.
Given how much downforce the test one made it should have a MASSIVE effect!
But anyway, to be on topic to the video, have you explored unsprung aero? That should quickly solve your squatting problem, plus it lets you run softer suspension all around for better mechanical grip at low speeds. Also, RIP GT car body and aero. Thanks for the video on DRS.
Really cool!... another great video. I've often wondered if a front splitter with this tech, attatched to a gyro would keep the front from lifiting if set right..?? Would create more downforce if car was constantly trying to lift up but if normaly level and just fighting the odd bump, maybe it would be good.... also if working with the back one, so had extra downfoce all around for coners and none for the staights... just a thought but I'm no expert.. independant sides would be another step so could add downforce to the inside through corners..
Very cool.
i already did this to my vendetta it works!
But was your vendetta "self flipping"? Lol
@@EngineeringAfterHours no, but it squats a lot!
Getting it do toggle automatically between high and low speeds would be neat.
Nice
You're inspiring me
Nice. Have you considered to try something similar to the active aero like the Pagani Huayra BC with both front and rear aero flaps that also help turning.
I have not but I'll watch some info on it to learn what it's doing!
Even looks like a CRL
Time to get more cunning. Dynamically adjust the spoiler angle so that it maintains a constant squat on the rear suspension regardless of speed.
Absolutely. I asked chatGPT to write me a code that will take input from a load cell and adjust the servo accordingly. That also allows me to keep aero balanced front to rear.
Incorporate F-Duct, too, please in your car(s)
On such a small light weight vehicle, wouldnt simply adding ballast weight result in the same traction advantage but without the added aero drag or a wing?
No, weight only helps to balance things. Once a car is weight balanced, adding weight only hurts.
You have plans for underside down force or an rc delta-wing clone ?
I've done the ground effects before, I may revisit that. I would really like to play with something like an aircraft catapult for an rc car to get killer acceleration.
Just because something is small doesn't mean its not gonna function !
Definitely. I've been surprised at how well these wings can work at RC scales.
Did anyone mention rake? Or shock limiters?
0:19 so, you made a mercedes?
Edit: oh, you already said it in the video
Haha...great catch!
How did you determine the angle of rotation of the servo?
I knew I needed the rotation of the drs elements would be less than total servo angle. I also had a smaller level arm for the elements than the servo horn. So that mean 1 degree of servo movements made over 1 degree of wing movement, and I needed less than 45 degrees total. From there, I just changed the servo end points on the remote to limit how far it could travel.
Thanks 🙌,Actually i am trying to do in my project is when my car's acceleration is more than 50% of total, the drs will activate, and when brakes are applied, instantly the flap would close.
Just trying to figure out how do i implement this using a servo.Can you give me some tips ?
@harshdoshi4800 I would use an arduino to take the pwm signal and convert it for your needs. So basically from neutral to half throttle, it tells the servo to stay put, from 50% throttle to 100%, scale to full open, and on the braking side...just use throttle as normal.
@@EngineeringAfterHours Thanks a lot man🙌🙌
@@harshdoshi4800 no problem and good luck! Chat gpt can help a ton with programming the arduino if you didn't already know.
I feel like if the whole car had a lower ride height you wouldnt have that flipping issue.
Unfortunately the ride height was about as low as it can be and still be drivable. Any lower and it catches on every little bump and seam in the road.
This just shows how dangerous underbody aero can be on cars with such a short wheel base. The pitch change over a small bump is multiple degrees. Whereas with long wheelbase cars, it's negligible.
>24fps
>Filming a small, fast moving object
**pukes**
Please at least use 30. I can give you camera settings to make any frame rate for any type of shot on most cameras look amazing. The main thing you gotta do is ignore the 180-degree rule and instead select a shutter speed in the 1/40th to 1/60th of a second range, and set shutter priority mode if you use auto exposure. You may need to buy an ND filter in order to shoot outdoors in bright situations after locking down your shutter speed like this, in which case, if you only want to spend money on ONE, get an ND16 filter, but if you buy TWO get an ND8 and an ND32.
Also, avoid decimal framerates (23.976/.98, 29.97, 59.94) and instead use full frame rates, or at least never get them mixed up in post without properly re-encoding decimal to full. Lastly, avoid non-intra-frame codecs and instead use only all-intra-frame codecs such as ProRes or if you use a Sony camera XAVC S-I not plain S or X. They preserve motion accuracy better AND edit faster/easier on your PC.
what shutter speed would you recommend for 30, 50 or 60fps?