Fastest RC Jet Car (Runway Testing)
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- Опубликовано: 21 сен 2024
- Here's what happened when I took my jet Car to a runway! For 16 free meals with HelloFresh across 7 boxes AND 3 free gifts, use code PROJECTAIR16at bit.ly/3PYcllR
This is part 3 of this mini series.
Go and subscribe to Mike Stallone's channel here! He makes some great speed running videos / mikestallone
Special thanks as well to the following for their help and advice during this series:
- Kevin Talbot / kevintalbottv
- Scorched Parts / @scorchedparts8013
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DISCLAIMER: This video is purely for entertainment value. Personal use of video content is at your own risk. Recreations of experiments, activities and projects are the sole legal responsibility of the person(s) involved in replicating them. I can not be liable for any information or misinformation, wrongful use, damage to personal property, death or any circumstances that result from replication of any projects seen. Be safe!
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Happy to help man! Really appreciate the shoutout. 🔥 This is such a cool project and I can’t wait to see where this goes! My unique build also went through some growing pains but every time out was a learning opportunity and now we’re at 185MPH! Keep going and always happy to help 🏎
thx for spoiling
@@KjekkasAron how in the world could what I said be taken as a spoiler? Unless you’re talking about my car 😂
just kidding man haha love ur vids btw
@@KjekkasAron 😂 you got me! You rock thanks so much
Sup, Kev
wooo! I made it into the vid!! thanks for the mention! was a pleasure to meet you. a few of us were using gyros, we have the futaba one. if it wobbles you can turn down the gain, but it looks like it might be picking up vibrations. i find the 3m double sided grey vba tape the best. cheers!
hi kev
Dang I thought kev would comment here I saw him dang what a crossover!!!
I new i saw kev on the footage
KEV! awesome to see you with this guy too!
Doh! 😖 wish I the car survived to get another run so I could have tried that trick with the tape and turned down the gains! The pleasure was all mine, man! Hope to see you at another event! 👍
That gyro would have been massively freaked out by the vibration. On RC helis, the gyros (flybarless units) are installed on an anti-vibration pad to help alleviate the effects, but the vibrations from rotary flight look like nothing compared the vibes you would get from running on rough tarmac. Looking at that, I'm not surprised the other guys didn't use gyros.
Yea, at those speeds the vibrations must be making the gyro think it has gone off center and then it tries to correct the movement that it's causing itself. The only way to fix that would be to record data from accelerometers and create gyro software with the right compensations.
Some of them used gyros!
Having a longer smoothing interval on the raw gyro data might help a lot with reducing vibration-induced oscillations. Only downside is the gyro becomes less responsive to sudden jerks, but I think for a speed car this wouldn't matter too much, since being smooth on the steering should help with stability at speed.
Raz Shifrin has used gyros on every one of his cars and he's one of the fastest in the speed running scene. To be fair, he uses Futaba gyros which are the best in the game (at least for cars anyways but I think they do alright in the flight world as well if I'm not totally mistaken). He has it turned waaaay down so as to not cause violent oscillations which only get worse the faster you go. Now, I know he said no one else there was using them so I don't want to rule out the possibility that Raz decided to change his setup based on the conditions on the ground but, at the same time, I'd be more than a little surprised if he did. As the old adage goes, don't fix what ain't broken. I could be wrong of course. This is just my initial take after having watched Raz for a few years and his approach to the use of available technologies in his vehicles.
@@JJayzX Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😁❤️
The fact no one else was using a turbine shows how interesting and unique it is. Don't let this series die. Keep it up!
RC car speedrun community seems like a fun bunch… thanks for putting them in the spotlight!!
You’re probably right about the slop in steering causing your oscillations. Might be worth adding some stabilized rudder surfaces and leave the main steering unstabilized
An aero-stabilized short-wheelbase RC car? Hang on, this isn't rctestflight!
@@bob2859 Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😁❤️
I LOVE how you always showcase your “mistakes,” and reframe them as learning experiences; especially with your infectious positive attitude about how much you’ve learned. This is such a great example to show my young niece and nephew; well actually for anyone for that matter! Thanks for sharing this fascinating video with us!!!
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😁❤️
Damn man, I'm 36 years old and have had an engineering mindset my entire life despite not going to school for it. To see someone your age making a jet powered RC car, then crashing, and having such a positive attitude about it, fills me with a lot of confidence about future generations. Keep developing your passion, by the time your my age your GOING to engineer something truly epic, and I can't wait to see it. Subscribed!
Failed in creating a 100mph car but succeeded in gaining valuable information on how to get to a 100mph car SAFELY and RELIABLY. Not to mention tips and contacts from the event who have the same pursuit. That's a win for any engineer and glad you think the same way!
Gyro in a car will reach an oscillation speed due to the servo max slew speed.
You can reduce the problem by mounting the gyro on the upright so it turns with servo (or doesn’t turn with the car in a slide.
What you need to do is use a flight controller like ardurover to have gps pid position control for the whole length of the runway and onboard data logging.
I second the flight controller idea. A flight controller would allow a lot more adjustment. I'd also add pitot air speed indicator and a quadrature encoder on at least one wheel to be better speed data.
Edit: The flight controller should have either a flash chip or a SD card for black box data. Lots of great information can be logged using programs like ArduRover.
@@ddegn
Didn’t think of using a Speedo.
The gps and accelerometers are pretty good.
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😁❤️
@@alunesh12345 Stop making Christians look like crazy people. Are you really Muslim trying to make Christians look bad?
Whatever you believe, stop spamming. It's EVIL.
@@alunesh12345
Why believe when you can know
Just rebuild the steering with all metal, high precision parts so it has no slop. Put rudders on the fins and have the gyros operate those instead of the steering. Experiment with speed dependent actuation %. The faster it goes, the less correction to prevent applying so much steering input it makes the car turn too much. Another thing to look into is detecting oscillation caused by the gyro. In that case it should return the rudders to neutral and hold them until wobble stops. If two rudder servos are used, they could be both turned to maximum outwards to act as air brakes.
One more thing, mount the engine with a little bit of upward tilt at the rear to push the rear end down. Having it parallel to the chassis is going to make it rock forward, putting more force on the front wheels. That will put more drag on the front, less on the rear, leading to amplifying the effects of steering and wanting to spin around - resisted only by the big fins.
One of the best series yet!
Edit:
I would love to see a mini Bloodhound build with the jet engine, as this would be realistic to the actual Bloodhound. (Because you mentioned redesigning the chassis to incorporate the engine)
It is. But I’d love to see the space shuttle return
Couldn’t agree more.
Don't forget his rocket plane program, pretty cool content too and he has a rocket that hit 700km/h
@@maxlobry4508 True. I enjoy the RC cars more, but the rocket series is one of the best on RUclips.
Or, given his penchant for classic design, something from the golden age of British speed record cars.
The issue with the gyro is that the steering sensitivity increases with speed. Meaning at low speeds the gyro gain is correct but at higher speeds the total output gain (steering + gyro gain) has increased causing the oscillations. I would not recommend a simple gyro for this. Maybe a flight controller with GPS to dynamically change the gain correctly for the speed?
I agree, gyro's require tuning, and you are operating it in 2 distinct scenarios, so you either need to tune it for high speed, or both, def not ONLY tuned for low speed (the way you have it now). The front suspension could be replaced and/or upgraded... I don't think the platform is stable enough for high speed passes without one, or both. I would also like to see some larger/stiffer/lighter gussets on your wing, it appears to be VERY helpful.
Quad flight controllers used to have all sorts of problems with vibrations inducing signals into the gyros. It was solved with speeding up the sampling and pid-loop and with advanced filters.
I doubt that gyro has what it takes.
@@ulwur Back in the day, before advance filtering, PID controllers had TPA, which essentially softened the gain as throttle increases. I think for simple controllers (such as this car in the video) could probably work by using a programmable gyro. There are some RC car gyros that can be tuned via RC link, which allows you to mix the throttle channel with the gain.
@@kwaaaa That seems ideal. I got into building quads 6ish years ago, and I have only heard of someone using throttle P.I.D. attenuation once... it doesn't seem to be necessary on drones. This car, however, seems like an ideal candidate.
@@MrFadjule at low speed the assistance of gyros is probably not needed. So just tune it for high speed would fix it.
My first thought was the servo. For those kind of speeds you probably want something heavy duty and pretty rigid, that may be part of what caused the gyro to get confused.
Yes. In the RC heli world they match servos to the gyro and their respective capabilities are known both ways. Makes wag much less of a problem.
If the servo response rate is too slow it won’t work with a gyro it has to be fast and strong!
That’s possible but I’m sure the oscillation is initiated by the input noise from the road. Without any sort of tuning there’s absolutely no way that the gyro will be able to work properly on a bumpy tarmac at 100 mph even if the servo was a good match. People will spend dozens of hours of testing to tune a gyro for a purpose like this because of the extreme conditions.
@@Chevsilverado yes I agree my stream liner uses 2 gyros one 3 channel for the aero and a gy401 for steering, shock absorbing mounts are critical but if too soft the problem will come back just like a slow servo,I e had some bad crashes tuning gyros in and even planes it’s not much different if u have snapped a prop mid air it usually doesn’t end well lol also just as critical to the gyro as servo speed is it’s location on the chassis it greatly effects its response! Having said that most of my speed runs are on very bumpy outback Australian roads so my cars are usually tuned on rough surfaces my best pass was only 218kmh but was done on rough loose surface roads and only managed a bit over a full second of full throttle but
it’s better than the xo1 on same surface only could do 150kmh before taking flight
Two suggestions: ditch the spektrum radio and go for something more modern like Crossfire or ELRS. If you want to use some active stabilization, go for something that provides you with logs so you can analyze the behavior dynamically.
ELRS ftw :) crossfire at 50hz is too slow for that kind of speed :P
ELRS with a flight controller to load the data and filter sensor input.
Great video as always. I really like you reflecting on changes, looking for errors and being able to find them, even when they're your own.
When going on with this project, I would strongly suggest looking into landspeed record cars and their setup. All of them are low-drag, low-downforce configurations.
Especially with no wheels being driven, a rear wing makes not much sense for downforce, however the vertical stabilizer is often used in LSR cars.
The rear wing will effectively lever up your front wheels, making the car instable at speed. A front wing to counter this or even a unified "central" wing (think aircraft aerofoil upside down) might make sense, with a small vertical stabilizer at the rear.
As I said, enjoy your content and the experimenting you are doing. Have fun!
Development is never a failure. The information you gleaned from this is invaluable.
Piece of advice, don't take aerodynamics advice from people who are not experts. Trust your own testing and then make any Nessasary changes. Good luck.
I'd invest more into the suspension. An inwards toe angle makes the car want to go in a straight line, where an outwards toe angle makes the steering more responsible but the whole car way more unstable. Positive caster also helps with stability. Camber can be used to reduce the patch area.
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)🥳❤️😁❤️
@@alunesh12345 Barakaka Allah feek.
Now while the sons of Israel were in the wilderness, they found a man gathering wood on the sabbath day. Those who found him gathering wood brought him to Moses and Aaron and to all the congregation; and they put him in custody because it had not been declared what should be done to him.read more.
Then the Lord said to Moses, “The man shall surely be put to death; all the congregation shall stone him with stones outside the camp.” So all the congregation brought him outside the camp and stoned him to death with stones, just as the Lord had commanded Moses.
Numbers 15:32-36
After watching a few times just something I'd like to add. Thrust angle from the jet is quite important. Jet cars for drag racing and landspeed actually slightly angle the jet downwards. Which seems counter intuitive but that's where your downforce comes in the trick here is balancing your downforce and thrust angle.
Your experiment did NOT FAIL at all. What it did was teach you a lesson and how to overcome it. I say that's a win win. I can't wait to see the new car!! You got this!!!
perhaps some kind of steering damper. it's something motorcycles also use at high speed to prevent a "death wobble" (kinda what your car is doing)
I think making a custom purpose built car is the way to go. Incorporate the engine into the chassis and really stiffen it up. Make some suspension components where you can control the wheel geometry (adding a bit of caster into the front steering wheels will help greatly at high speed). Beef up the steering servo as well for rigidity and crash resistance. Even make a new new body shell out of fibreglass or carbon fibre to cover the chassis and engine as one piece. Don't really need to worry about too much weight as you're after top speed instead of top acceleration (though heaps of weight would make steering difficult). Fantastic vid as always 🙂
It's so cool seeing Kev, Raz, and Project Air all interacting!
i like how the replay feature lets you see that you are not the only one that skipped the sponsored ad
Spektrum radios are great but have some of the shortest ranges of radio systems I have used.
For this job maybe you could look at some other radio systems used for long range drone flying or something like that.
Kevin uses the "Dumbo" RC radio, it might be better for this type of project.
Nice work. That guy saying it was the fins was talking rubbish.
gyro's are programed to work at acceleration around g (10 m/s), it gives different outputs at higher accelerations. you can use accelerometer for correcting gyro's output.
I don't think this is correct.
Accelerometers are used to correct a gyro's sense of "up" in a flight controller. Gyros drift over time but the type used in the video don't need this sort of correction since it's only tracking a single axis of rotation.
This is truly how educational content should be presented - highly valuable and greatly enjayable.
Here's some suggestions which hopefully may help before it's next run.
Cut out the body around the engine so you can lift it on and off easily.
Turn down the steering 'dual rate' on the transmitter to about 60%, it'll make it less 'twitchy'.
If you run the gyro make sure the gain isn't too high, you only want the gyro to assist, not totally control.
Add a separate failsafe or kill switch for the engine so you can kill it remotely if possible using an aux channel.
Swap the receiver out for an aeroplane receiver as it will give you more range.
Hope that helps :)
Agreed. The engine shouldn't need to be removed to access the fuel tank. I'm sure he'll make these changes. It looks like he was rushed this time.
Is it possible to output a log file of the gyro data? Looks like the gyro is both causing instability, and correcting for it, keeping it going straight. So maybe some sort of resonance or delay with the servo, or linkages?
Hmm. You can fix the sloppy steering by deleting the servo saver and replacing any worn-out or loose rod ends. The gyro is fighting hard to compensate for the sloppy steering mechanism and you do indeed get that wobble at higher speeds, resulting in oscillation ( might not hurt to turn down the gain to lessen that side-effect ). I would also recommend some foam or 3D printed side skirts for the chassis to stop the sides of the shell from flopping around in the wind and getting sucked into the wheels as you were warned about at the track.
Also, Kevin Talbot is clueless and thinks brute force and clickbait titles will make him have the fastest r/c car in the world; I wouldn't take too much advice from the likes of him.
Kevin is fun to watch, but he better at bashing. Giving cars the great send-off into the sky!
@@pauljs75 true, though I think that's what bothers me and a lot of others; he buys brand new cars and trucks and smashes them to pieces instantly in the name of 'content'. Something about that rubs me up the wrong way, I just don't find deliberate destruction amusing, vs genuine bashing and having fun that _might_ result in relatively minor damage.
another good compensation is slight camber in on both so the tires are pushing in.... on my 120mph rustler i found this to work very effectly. sure tires will wear faster but it is better then destroying parts
I enjoy Mr. Kevin’s you approach to solving problems,,..admittedly, I as well as most others in this hobby can’t afford to engage in such expensive endeavors like these, I appreciate that both of these chaps have the means to indulge us.
Speedrunning RC's is no joke... gyro's are amazing tech if set up properly. another trick we speedrunners use is turning down the dual rate of your controller so any steering inputs are dulled out a bit more. (you can also do this with negative exponential values). Dont get your head down. I got out of the game after a nasty crash that totalled my ride but the thrill of watching your build go by can't be beat. Good luck out there!
Need to mount the jet very low and as far forward as you dare - Use some duct work for intake and exhaust. You could use a venturi effect for the jet thrust to create some downforce by sucking some air out from under the car. If the centre of drag/lift is behind the centre of mass it shouldn't go out of control so badly, and at speed it will become even more stable.
Jet engine for suction? That's a easy way to ingest as much debris as possible.
Was looking for a comment like this. The amount of thrust is just too much for a car that light, it completely dominates any aero the car has.
Pulling the car forward with a front mounted engine seems like an obvious (and not particularly pleasing to look at) solution.
the c/g is off where it is.. it needs to be 50/50 or 70/30 its better for a jet engine to drag on the ground then push in my opinion...
I love how the Genius's in the trade are so supportive and un-biased towards further ingenuity. What a great Hobby... If only Government could be as transparent as this with their invisible budget to explore exotic tech
The reason for some of the issues is due to your braking i believe, if i remember correctly you are braking with the back wheels.
Full-size cars brake predominantly on the front wheels for a reason. When you are braking with the back wheels you are essentially moving the center of stability forwards, past the center of gravity. You see this effect when you are driving on ice and use the handbrake. rotating wheels have higher lateral grip than spinning/sliding wheels.
The wing helps to counteract this, keeping the center of stability behind the center of mass until you lose enough speed, at which point you lose control. This might also be why it stopped wobbling when the motor gave full gas again, just to crash.
A relevant example with wheels and grip that may be worth mentioning, when you are braking and accelerating you are essentially borrowing lateral grip.
When a FWD car accelerates too hard in a corner they crash front first
When a RWD car accelerates too hard in a corner they crash ass first.
the same holds true with front brake vs handbrake.
The fact that the center of thrust is above the wheels is probably also adding to this, by putting more pressure on the front wheels during acceleration. Cars which use a normal motor which spins the wheels have a center of thrust that is both at ground level, and is in the same direction as the ground itself.
Yes to me it also looks like the wings actually was the reason for it not to perform worse in the wobble period 🤓
Sorry to write this, but you are wrong. You can have a blown up tire on the front wheels of your car and control it safely to the stand. But a blown up tire on the rear wheels will spin you out of control. The back wheels is what is stabilizing your motion. The front wheels are for steering the car. The same goes for braking. If you brake only on the front, you move the braking point in front of the center of mass, making the car instable. If you brake on the rear, you move the braking point behind the center of mass.
The pitch of the car towards the front while braking (forced by the suspension) moves the center of mass also to the front and makes it necessary to have bigger brakes on the front than on the back.
@@Craftlngo Part of that is exactly what i'm describing. The back wheels is what stabilizes the motion, when you brake to the point where the wheels start to slide you lose lateral traction. This is why braking only on the rear wheels causes you to lose control.
Braking to the point of sliding is analoguos to the tire blowing up, just to a smaller amount.
Braking the back wheels to the point of sliding moves the center of stability forwards by an immense amount. This is what i described at the end with the braking on ice.
I am sorry if that was unclear.
Something i also have to say is that the center of mass is always the same, What changes when you brake is not the center of mass, but the direction of "acceleration".
All things experience 9.8 m/s/s, ie a 1-60 accelaration of about 3 seconds constantly, That is gravity.
When you brake you add an additional force - deacceleration. That force if it equals 1g(9.8 m/s/s) moves the direction of acceleration 45°, putting the center of pressure on the wheels forwards, which makes the traction act as if the center of mass is moved forwards.
@@Ganbalf ah ok, English is not my native language. Quite likely that I didn't understood a part correctly.
Two things need attention immediately before you move forward. 1st. Spectrum radios are prone to interference from high power wifi telemetry. We proved this at Flite Fest when people fly near the pump out in the field. When it pulses its data (and this is not bias for radio types) spectrum radios tend to fail safe if within the direct path of that pulse. I assume an airport uses similar devices for various things they need to track. Look into that or swap radios or receivers for better.
Second: Gyros are SUPER sensitive. Vibrations will drive them bonkers specially if it hits a resonant frequency. IF you intend to use one then you need to look into some kind of soft mounting to isolate the gyro from any part of the body. Bumps and bouncing usually won't effect them to much if the gain is set properly. A resonance however will totally bork the system and may as you saw induce a drift or totally lock what ever it is controlling. (This is actually what I think happened on this particular run but the radio stuff needs to be checked in any and all cases)
I have a theory. If you are pushing it with thrust from the rear of the car it's less stable. My theory is that you move the engine to the front and give it just the right angle to keep it slightly pushing down similar to the current setup but slightly more and sorta have the chassis be following along. This would increase the downforce and imo increase stability. The large upright wings would still be needed. Very neat project you have. Lots of luck to you
Robert Goddard, is that you???
This car wasn't a failure. This was the beginning of success. Think about much you just learned from this experience. To call it a failure it's an understatement.
Really interesting attempts and development iterations. Being into liquid rocket hobbies my first glance at your construction made me wonder why you haven't slush plates in your fuel tank? The fuel might start oscillation wildly at an unpredictable speed because of this. Might just be one of several reasons in combination. It would be easy to eliminate this, just by filing the tank half way up with a few large metal spiral chips from a lathe or from drilling.
Yeah that was a thought that crossed my mind too.
Colin, COLIN! Yeah your lads at it again, yeah the Jet thing, yeah I don't know but it's on fire pal.
You've demonstrated one law that affects many hobbies. Others in the hobby will be quick to tell you what you're doing wrong, with little, to no evidence to back it up. Following their advice blindly would have seet you back. Every hobby has these people.
The best scientists show their mistakes and failures. You are awsome!
Why don't you position the jet engine even lower and make scoop for air intake.
That’s a good idea
@7:00 yes - that is exactly what I was thinking you need. If you can get that engine down low into the body it will be a game changer. Take a look at how a jet dragster or top fuel dragster is set up to go 300+ miles an hour in a quarter mile.
So amazing to see. You have influenced the way I do my projects now
I’m not an engineer, so I’m sorry if I’m dumb for even suggesting this, but if you wanted the covered wheels with it having no chance of it rubbing against… maybe try putting two runners (would be part of the frame) along either side of the vehicle, similar to modern go-karts, attach the cover on top of that? Just a thought, might have other unforeseen consequences though. Either way, love this! First jet-powered RC I’ve ever seen. And it’s beautiful
Loved this project. Would love to see you push forward with this 👍🏻🍻
Really enjoyed everyone else at the runway being 100% confident and 100% wrong in telling you how to do your job
Any unwanted vibration or oscillation is bad. They have a point. Literally everyone else has extremely rigid vertical stabilizers for a reason. Obviously what is a known good formula is going almost twice as fast with far less drama.
Amazing work. I would add dividers in the fuel tank to stop the fuel sloshing around, and lower the engine as much as possible by cutting out some of the moulded shell and 3D printing a aero housing.
Raz shifrin knocking out the wing competition „Its rubbish, you have to get rid of it” 😂 love it
Yup someone is falling into the deep rabbit hole of RC speed runs :), great vid and awesome seeing Kevin in there as well.
I’m not an engineer but here’s my unsolicited $.02 anyways.
It would add some drag but I would recommend pointing the front of those massive fins inwards so if the tail goes to the right the left fin will be more streamlined and the right side will cause more drag pushing the tail back to the left. In a weird way this would act like dihedral in a wing and be positively stable both statically and dynamically. Also ditch the gyro though I would have tried it too just like you.
Great vid BTW
Great series! I think it would be really useful if you installed some fpv gear on the car so you could more easily steer it and get oscillations under control faster
100% the Gyro gain causing that 'oscillation'. I'm not sure how much you can turn it down on them ones. If you are going to continue to use one, have a look at the Onisiki 3 Axis one. Super precise and easily adjustable gain from your Tx. Look forward to seeing this hit triple figures. (Edit: watched till the end...yes, agree, slop and gyro) :)
Hi, I think I have a really easy improvement with large benefit: The oscillation is dramatically worsened by your fuel tank. Look at a tanker for example. They have ridges inside of the tank to stop the fuel from flapping arround too much
You're bringing the heat at the event up, and I can totally see how you could have made that error with the radio. Heat is no joke - I've had heatstroke exactly once, while I was a camp counselor, and I never want to experience that again.
Stay hydrated, homies! Seriously, though, hot weather can be a killer, especially if you're not used to it.
It was a pleasure meeting you buddyx
From an engineer with 20+yrs of experience, awesome video & engineering content!! 😎👌
Also, as a speedrunner, when it comes to gyros, I prefer to keep them off. The problem that I have experienced with gyros is that if a wheel looses contact with the road while the gyro auto correct... Well, it's going to over shoot your car in the wrong direction.
A tip that I'm not sure you have implemented yet is to switch the diff fluid in the front & rear diffs to 1mill, that will help keep your car in a straight line.
Just some thoughts, good luck 🤞 🍀 👍
Your experiment was no failure . You learned from it , knowledge is invaluable
ProjectAir: *jet car idea* Also ProjectAir: *Alright now who’s house are we selling?*
I guess some pesky rules might forbid the use of autonomous steering using mmWave/microwave beacons aimed along the track in a sort of nanoscale ILS guidance system? Do you have datalogging on the servo and gyro? Is there any sign of the gyro outputs maxing out? Can you map the gyro gain and PID control loop parameters to vary with speed? How about using explosafe cellular filler inside the tank to reduce sloshing? Compliant/damped mountings to reduce high-frequency vibration noise from the track surface? Kalman filters to manage measurement noise? Viscous damping and maybe spring preload of the steering mechanism to take out any backlash at the neutral position of the servo? Looks like a huge amount of fun to be had. Great seeing the evolution of this project.
These gyros get weird when there is a lot of vibration, many have the ability to be toned down with a potentiometer on the radio but I'd just not use it. The wing seems to be giving you plenty of stability at speed. Maybe turn the rates way down so the steering is very mild. Also I'd get a surface radio, it should be easier to drive with a wheel rather than sticks. Raz knows how to build a damn fine car and his perfect pass servo is epic but he comes off as a pompous know-it-all calling everything garbage and whatnot. He was doing it to Kevin in his last video too.
I was just think that this would be a perfect place for Kevin to take his "Project worlds fastest car" and there he is!
Someday I'd like to see a hobbyist build a simple laser guiding system that you could just place at the end of the track so the car would home automatically to it. Steering a high speed RC car is just a recipe for disaster. The gyro is a good idea though!
Sorry for the late comment. Enjoying watching this jet car go. I caught it at the end of the video. Loss of signal and the fail-safe problem. That problem starts with the DX6e. The e models don't have the diversity antenna system. The single antenna has good range to the sides of the transmitter, but if you point the antenna towards your car, plane, whatever, you are effectivity putting it in the cone of silence. I happen to like and use Spektrum for flying. Just not the e model transmitters. I've seen planes lost because of antenna being pointed towards the bird at half the distances I fly out to with only a dozen dropped frames on my DX18. I'd bury that 6e in a shallow grave at midnight and upgrade to a full DX6, 8 or better before attempting another speed run. Good luck and keep the vids coming.
I appreciate you adding the error search at the end. Not as entertaining, but immensly insightfull
Absolutely correct. I play simple Rockets 2 and it's fun testing and engineering crafts of any kind in the sandbox, designer , and test and play in a physics world. Try simple Rockets 2. It's definitely up your alley
Easley the best solo RUclipsr of RC Planes
As soon as I saw you were at Rossa I knew Kevin Talbot might appear in it somewhere.
Also heard Raz Shifrin giving some design pointers as he makes some insane speed cars.
Now I just have to wait to see their videos of the event and Kev showing us your car in his video.
I suggest using an ardurover based flight controller for gyro. I'd also recommend using a capacitor to keep the power to the imus nice and clean. You could even use an arduplane setup and use rudder/elevator for control
I also think something like a flight controller is the way to go.
I use gryo's on gas turbine powered RC jets which routinely fly in the 250mph speed range. What I can share with you is that whilst a gyro can greatly improve stability, at a given speed, the effect you seek at one end of the performance envelope is actually very different at the other end of the envelope. Typically, the faster you go the less gyro gain you require. Using a level of gyro gain which gives you good stability at low speed, running the same gain at at high speed will almost certainly cause oscillation. On an RC jet we like to have a decent amount of gain at low speed as it helps with stability and counteracts any side wind effects when approaching to land (extremely beneficial when landing your £10K toy), however that same gain level can become problematic at high speed, as control inputs become more sensitive the faster you go, hence less gain is required. So how do we address this in RC jets? The gyro gain is adjusted in accordance with speed (the faster you go, the lower the gain required) and this is facilitated by data obtained by a GPS unit, or a pitot tube. The pitot generally being more accurate. In the absence of an ability to detect speed telemetry then just set a low gain setting to optimise high speed handling. It's almost always better to have too low gain than too high. No gain tends to equate to gyro off. I noticed a gain channel on your gyro, so you could run that into another channel on your receiver and put the gain setting on either a switch or a knob. If you assign to a three-way switch you can effectively disable the gyro at zero at one end of the switch. Just a suggestion.
Something to note on your radio and gyro test with motor and ESC on your bench. It looks like you were getting some interference from somewhere. If that is from the motor and ESC then that may not be a factor when you're running your turbine, since they are not present. However the turbine can indeed generate interference, or even the fuel pump, when running at speed. Consider using a turbine oil which contains an antistatic additive, as this can help with the build up of EMI caused by static. It's more common in some turbines than others. Jetcat sell their own turbine oil which contains an antistatic additive and you can get it in the UK and it's not much more expensive than regular turbine oil. Give Dave Wilshere at Motors and Rotors a call, he stocks it.
On a different note, I'm a bit surprised that the organisers did not insist on a radio fail safe check before any run was attempted. Whilst it's not reasonable for an organiser to be responsible for the general safety of your car (though it was nice to see the community helping you with the body work, hats off to them) it is totally within the gift of the organiser to insist on scrutineering the failsafe function of your radio. This is something I see done at RC jet events all the time. At the start of the day we go through scrutineering before our first flight and demo the turbine going to idle during a failsafe event. When you pass this check they put a coloured sticker on your plane and you're good for the rest of the day. It's just a sensible safety precaution and it's actually really good to reinforce your own confidence in the safety of your setup. I know some people are going to say that RC cars and RC planes are different beasts with different risks, but failed lipo batteries or a short in your electrics can start a fire reasonably well without the need of any fuel. Given that a radio link at ground level is much more temperamental than a radio link to an object in air, a failsafe check is particularly important as failsafe event is far more likely.
I've been in the RC hobby and flying jets for almost 20 years, and I am thoroughly enjoying your channel. I particularly enjoy how your break stuff down into the different steps on your journey and it makes for great viewing. Please continue with this project as I'd really like to see you get a gas turbine powered car somewhere near it's real potential. I truly believe you're on the right track with the incremental improvements you're bringing to the project and I'm really looking forward to another instalment. Please don't stop now ;-)
I'm now a confirmed subscriber to ProjectAir !!!
I wouldn't discount Raz's advice too early, he has a track record for knowing his shit when it comes to speed runs. The gyro could simply have been reacting to forces applied to your wing, if your wing is getting disturbed at high speed your gyro will try to combat that. Just taking the gyro off doesn't prove anything, as the faster you go the more your wing needs to deal with, this is the reason Raz's wings are made from carbon fiber and shaped like they are, so they are super stable at 190+ mph. Just be cautious in thinking that it's only the Gyro at fault here. With all that said, love the build and your channel is great!
You could add an fpv camera to get a drivers pov, instead of turning around everytime the car passes and hoping you go off track (plus the help of the gyro). You can also go even further than you used to because you can see everything in front of you. The only problem being cost.
More of this project please, it’s awesome!!!!!
A couple more tips for improving handling,heavier silicone oil or smaller valves in the shock’s and more spring rate on the rear will do more than fuel line,also you need Less front traction! You want to go straight so put grip on the back and as much as you can! and a set of Harder compound tyres on the front, if using foam you can shape the front tyre’s so it acts like extreme negative camber ie not cylindrical but conical profile the added benefit is the narrow point of tyre touching the road is easier to compress and will absorb more bumps and more aerodynamic! Hope this helps!
Awesome project. However, this is not a car but a plane without wings 😉
For the sake of aerodynamics, why not leave the "windscreen" on the body clear and position the camera inside? It's unlikely to make a huge difference, but more balanced airflow might help with stability
Very interesting. Gyros can be finicky & sometimes very counterproductive. I use them on all my speed cars, but learned to keep them dialed down. At first I thought I “needed” all the help I could get & turned the gyro all the way up. Couldn’t figure out why the car was all over the road.
I keep an eye out for your videos & always enjoy them. It was great to see Kevin on this video & I think I heard Raz in the background also. Best of luck going forward. JOE M
"all my speed cars"
Where are the videos?
It's always fun to see other people's projects. Don't worry about production quality just shoot some video and upload it to RUclips. Just don't shoot in vertical format.
@@ddegn Thanks so much for your reply. You are a very talented young man. I am just an old man that loves building fast RC cars…certainly not the best at it. I do the best I can & I get a lot of joy in the hobby that would otherwise be missing from my life. Keep up the great work. You are always a pleasure to watch.
So Many People Giving Advice...
INCORRECTLY. Here is some,
REAL SIMPLE & CORRECT ADVICE.
THEE CAR... is not the problem !
If you're concerned about failsafing, ditch the Spektrum gear and convert over to ExpressLRS.. You won't failsafe with it.
Perhaps a more advanced flight controller might be able to help as a substitute for the gyro as well. Just some food for thought.
Awesome project mate, love it 😊
Just wanted to throw in that it sounds normal that the gyro freaks out when you do a dry run with the wheels off the ground - like that steering has no effect on the orientation of the car, so the feedback loop is broken. It's like when you take the props of a quadcopter, it'll just try to throttle up like crazy to try and get control over it's orientation unsuccessfully.
If you left the gyro at factory settings, it was likely set to 50, 75 or even 100% depending on the model.
I use a maximum of 19% gyro gain if I'm driving 40mph+
Most gyros are way too sensitive at anything above 25%
The Spektrum AVC gyro has less speed wobble, but the AVC also effects the throttle input, which you don't want, so avoid AVC receivers.
love that you included kev
2:37 The good old percussive maintenance!
You should really set the gyro gain to a nob on the transmitter so that you can adjust the gain on the fly. You also need to make sure the gyro is completely isolated from everything other than the chassis with a good double-sided gel tape. Even wires touching the gyro can cause oscillation. It might have not been the cause of the crash but I would prevent it from becoming the cause in the next run with the car as speeds increase. I use that same sky RC gyro on my speedrun car. I have had it to 168 mph with no issues. It just needs to be set up and installed correctly. Hope you have better luck next time. In the last video, I actually mentioned hooking up with Kevin Talbot. Glad you just happened to meet him. I love that crazy guy, lol.
I love that regardless of size the jet still sounds like a proper big a$$ jet.
@ 11:47 but then, you ran out of radio range and your car wiped out, again. Brilliant!
as a recomendation I suggest that you try to make the car larger and removing the rear wing, also it would be great if you made the vertical wings thicker as they are more aerodynamic if you give them shape than a simple flat wing
Yes i do the same with electrical projects, start at low power. And if it works, turn up the power till it breaks down. Good way to learn the limitations
Respect to you for making that actually really good looking Tofu/Greenbean meal lol
Found ya from Kevin’s video. This car is awesome. You’ll pick up the pieces and run again. Great video
Gyro gain and non isolated plus steering slop. Bin it off the steering and add it to the vertical stabilisers with rudders. Also use a quad flight controller with inactive so you can data log. They are cheap enough and you can use car or boat profiles. Also, spectrum and loss of signal, who’d of thought it.
I'm so sorry that happened! Can't wait for the return of the car.
Yessss! Amazing build
I think your center of drag is too far back for your center of gravity also. Great content brother. You're the man
I think this idea has huge potential
Yeah as an Aussie I can't help think ... was it really hot ! Seriously LOL... good vid young fella
RIP jet car :( It lived a long and glorious life. Can't wait to see whatever is next...
No disaster there, great learning project, you did say you were running to its limit and now you know allot more.. very interesting
Was so strange to suddenly see Kevin lol. Never would've expected you two to meet