@1:48 What you don't have is not just independent suspension, it's roll articulation. A conventional beam axle suspension is not independent, but it does articulate in roll. I'm surprised that you didn't mention that the same thing (swingarm, no roll articulation despite two wheels on the axle) is still found on quads, and they all used to be that way.
Hi Matt, Have you considered the effects of the caster jacking on the completely warp bound design you have there? I think the system would be improved a lot by introducing some warp freedom somewhere in the design. Rear bay chassis looks like a likely candidate. I don't think it would be possible to go too soft at all, but you would want most/all of the roll resistance at the front, which I suspect is the heavy end also. Another option might be to get your steering trail with an offset spindle rather than caster.
Hey Matt - is it annoying when doing orders for Send Cut Send with like a 100 little parts? I've only put one order through them for 10 of one item (EV battery cooling plates) and found that it was MUCH cheaper when ordered in multiples and each part had to be it's own file, so I'm curious if you had to upload like 100 individual files or if there is a way to package it all together and export from Fusion 360 or whatever you use. Thanks! It's coming along great!! :)
actually Matt a video with you talking about shaving your junk would be hilarious cause you'd build some overly complicated and highly sketchy scrotum scalper, then segway into the dood trimmer sponsor seamlessly. id watch that. lol
Land speed racers seem unconcerned by weight, so they won't use aluminum. According to Matt's earlier video, the rules are quite specific and likely don't allow aluminum. Hard alloys can save weight (which they don't care much about), but they are also more brittle; mild steel is safer.
Safety is over-rated and all, but did you do any analysis of braking forces? And consider the (low) possibility of front swingarm pivot failure? Would suck for the car to steer left or right due the pivot location flexing under braking forces at the end of the track. Or worse, a fatigue failure occur at one of the bearing mounts.
There won't be brakes on the front, only the rear. I also waaay oversized the rod ends. even with the stress riser of the threads, it would take an enormous force to break them.
@@SuperfastMatt I was more curious about the bolting location on the chassis for the rod ends and the stress that area will see. Anyway, if there's no brakes on the front it's (probably) all gravy! All hail the algorithm!
I think some of the pace of the work comes from the confidence to make a decision and proceed with it, and the willingness to rework the parts of the project which don't work as desired the first time.
Well. It all makes sense to me, you're the guy who's an engineer, oh wait..........I have cussed engineers for years......eh you're cool. I'll trust you....... At ECTA Blytheville Arkansas there is a dip in the surface. In my slow Neon on coilovers it is extremely noticable. I think suspension isnt a bad idea.
Ha! "Engineering is the applied science of laziness" is honestly how I've often explained things. (laziness for the engineer, not for anyone around them, before mechanics comment)
Best automotive channel for nerds on RU-vid! “Engineers make the world a better place by making it easier to be lazy” Great quote (engineer here) but I know a lot of technicians and mechanics that would say the opposite!
Engineers make it easier to be lazy* Unless you're German educated. Then it's "How complicated can we make it and how many special tools can we create to complete a simple task?"
@@TheRealWTFGarage i can answer that with a joke: how many Germans do you need to change a lightbulb? One. They are efficient and don't understand fun.
@@TheRealWTFGarage I worked at a Volkswagen dealership, there were special tools for EVERYTHING. some really good, but need to lock out a cam gear with a round cylinder shaped thing? you could go to the special tool cabinet and hope there was a free set, or just use a drill bit of the correct size. guess what anybody but the interns did :P
We need to petition RU-vid to bring back the 5-star ratings instead of "all we have is this thumbs up thing", for videos just like this. That was the most entertaining synopsis of suspension theory packed into six hundred seconds. Thumbs up for 5-star! Thumbs down for thumbs up only! #AllHailTheAlgorithm !
Thank you for not talking about your junk or the greatest new fishing app you’ve “found” and “actually play!!”. Makes me cringe everytime I see it. Love the clean crisp content. Short and sweet and everything you need.
Love the video but the thing I love most is that your explanation of suspension movement at 2:58 used an image of what looks like a classic mini which actually has a system that is not dissimilar to that of a bikes swinging arm but with only one side supported and rubber cones in place of springs. A fascinating design that was created to fit in a tiny little car.
Two things, isn’t several 3d objects put together to make a 4d object just a clock?? And two, tab and slot details are great, if you have trouble with the corners fully seating, add dogbone radius to your slot. Save yourself the headache of maybe needing to get a file out Having fun watching. Good luck!
Getting back to the lazyness comment, dogbones take ages to do in CAD but it doesn't take long with a file on the part* :) *Assuming you're making a 1 or 2 off of course...
he was talking about purely spatial dimensions, which string theory says there are at least 10 of, calling time a dimension is to help our feeble human minds that aren't experiencing near-light speed try and understand the idea of space and time being interconnected/interchangeable. also dimension as in another 3 dimensional universe in multiverse theory exists and is completely unrelated
The steering linkage, with the U-joint to isolate the steering from suspension movement, is clever. But tying the two side together at both the handlebar and the axle seems more "over-constrained" than "redundant".
Laughs in heavy aircraft mechanic trying to blindly reach a nut through a 5" diameter hole, overhead and backwards because that's the only way to get your arm to bend the right direction, while standing on a ladder.
Lol, at every corner the Engineer turns there will be Tradesmen who don’t understand: - Project time constraints - Project budget constraints - General competing design requirements - The requirements set by external stake holders that the Engineer has no control over but must meet - Etc etc
You should do a video on the modelling software you use and a few tips to get a noob started. Am I being selfish - hmmm clearly I am selfish AND overthink too - dang
How did you determine your caster angle? What angle did you decide to run? I like more than most vehicles come with, especially American vehicles. But I’m not going 200 mph. Thanks.
I literally LOL'd at the math class reference. **Shudder** Man, that was a part of engineering school that my subconscious had suppressed to protect me.
One interesting tidbit about motorcycle steering is that motorcycles counter-steer. I find when I get on a jet skii I typically turn the wrong direction on accident a few times before my body remembers that not all handlebars are backwards. Please dont do that in this at 150 mph 😅
The one thing jumps out at me with your steering mechanism if employed as designed, could result in "Super Fast Impaled Matt" should anything unpredictable happen.
If you’ve ever looked really closely at a Porsche 911, everything is very well engineered - in isolation. But together the idea is as bad as it’s possible to get. The engine is hanging out of its A$$$. The gearbox is over the axle, okay, then they have to add lead weights to the front bumper for when the fuel tank (which is in front of the driver and passengers) is not full…! Porsche did make great cars once. The 928 and 944 were excellent - because they were well designed AND well engineered. It’s not an easy trick. Using bike design suspension is a good way to go with this project. What engine are you using? I’ve missed a few meetings.
Be a little (or a lot) careful with the first few drives. Motorcycles and bicycles counter steer but cars steer. You might find yourself drifting in the opposite direction of where you intend when you first drive it. I had this happen in college when I rode one of those big adult trikes. Handlebars felt bicycle like and I would drift into parked cars until I realized what was going on. You may find that handlebars make your first attempts be to control it like a motorcycle.
I have found front suspension geometry to be the most difficult aspect of DIY building. It’s easy enough to understand the basics. But the actual engineering becomes exponentially more complex requiring precision i am not capable of. Good solution. I am worried about your handlebars. It’s significantly more difficult to modulate 2-wheel front steering with your setup. This push-pull will not feel at all like a motorcycle because there is no intuitive feeling you have when turning/leaning both machine and body. Think small old crummy quad-cycle, at speed. But I’m sure you have thought of all this and have accounted for my misplaced concerns. I can’t wait for a test run!
Don’t use that type 2 bolt flange bearing for the steering. That stamped sheet metal type are…. Not amazing. I’d use a traditional cast housing type using spherical inserts. Cheers 🤙
Yeah, obnoxious sponsors made be unsubscribe from a lot of youtube channels over the past 6 month. Which made this one pop up for me I guess, since I no longer see their content. The paid promotion stuff on youtube videos has really gotten out of hand, especially with the number of VPN services that pretend that surfing the internet is unsafe if you do not use one. (while the contrary is true, depending on the service used)
"I'm splitting the difference between suspension and no suspension. I'm basically building a jeep." It's funny because it's true. Watch out for death wobble.
Good luck with the streamliner! not an easy thing to go over 200mph. You can get semi-independent wheel motion if you tune the torsional flex of the swing arms. Makes the design a lot trickier though as they're a spring and you can't just throw steel at the problem. Afik, it's a good idea to have some suspension so you can damp tire bounce. Oh and chain can twist 10-20 degrees without issue, I think sprint cars often do this. I'd recommend a plastic chain guide on both sprockets to grantee that the chain engages properly. (dirt bikes have a chain guide at the rear sprocket to do this)
That makes sense, but to keep the torsional deflection (vehicle roll motion) from being undamped, it would need left and right dampers (shock absorbers) mounted as far outboard as possible.
@@brianb-p6586 spot on with relocating the dampers. There will be cross coupling between bounce and torsion so it will have some damping. Might be enough to rotate the connection to the swing arm 45 degrees so torsion pushes on the front shock and pulls on the rear or vice versa.
"This isn't the best suspension, but I can't really fit a differential and a four link in the back of this thing" you can fit anything into anything with enough force
Be interested how it feels steering when you complete it. Being a motorcycle rider for many years (like I think you are) jumping on the old original jetski opened my eyes into counter steering to turn corners and even keep it going straight. Took about 30mins to get the hang of things and stand up then I jumped on my bike to ride home and wobbled off down the road
The tabs are my biggest improvement in engineering ever, it is so much easier to get someone to weld it up as it is just like a puzzel. It fits a lot of ways like a puzzle but is only right one way.
My favorite engineering quote “ anybody can build a bridge that doesn’t fall down. Only an engineer can build a bridge that just barely doesn’t fall down”. Or something to that effect…
Really cool project but please think about changing the rod ends on the swing arm to spherical bearings (mounted in some kind of bracket) Rod ends work well with axial forces (I.e pushrods), but bending loads can cause them to fatigue and break. Especially in this kind of set up with stiff suspension
They are so massively oversized, it would take an act of God to break them. Especially considering the vehicle will probably never see more than a few dozen minutes of actual track time in its life.
Serious question Matt; (by the way I LOVE your channel and humor) some land speed record cars have a vertical stabilizer. Due to the nature of airfoils, they providing increasing lift (and or opposing drag) at increasing angles. With my arbitrary understanding, these angles seem to me like in a car you are in big trouble already, likely well beyond recovery, once the fin starts really doing something noticable? Could you elaborate on this?
It's already working when the car is still straight, it's just that the forces are balanced out. As soon as any deviation is made in yaw, the forces unbalance in a way that will simultaneously attempt to correct the car's yaw.
Matt, I'm sure you already have a video on this, but what CAD program do you use? I graduate in a few months and am trying to determine if there's a good free option versus buying Solidworks or another commercial-grade piece of software.
