ORIGINAL: piddlefoot

No offence to the creator, you have been very imaginative, but l see many flaws, the first being with its name, revolutionary, theres nothing revolutionary about it, the revo has more wheel displacement by a country mile, a top of the line rock crawler can pivot the entire front/rear end, so its out classed for rockcrawling, it is bulky, and has many parts alligned in a way that any damage would mess up the whole works, it lacks flex, if its rebuilt in plastic for flex, it becomes all mushy having to many joints.
Its heavy in comparison to most RC cars trucks or buggies, and has far to many parts, joints, and the steering is extreemly vulnerable, that vertical shaft that is also a CV like joint, is going to get dirt in it and will also bend under very small impacts.
All the extra steering components will mean more steering slop faster.
It looks like it lacks caster adjust, that front end should be castored like a HPI baja.

And whats the point of having a collapsable double arm system that can move less overall distance than a revo and around about the same distance as a current 1/8th buggy ?
Had you targeted traxxas's revo [1/10th scale ] design and made one better, you would probably become pretty rich.

To be frank, it looks like a NASA design. Slow and cumbersome.

Nothing personal, but l think you need to keep an open mind if your planning to invest alot of money into this project, l would re-design the whole thing to have as few parts as possible.
And l personally believe a better system will look more sexy than the revo system, just as the revo system was more sexy than the old tower set up when it was released.
Its neat, [ revo ] looks wikid and works better than the tower set up, that is what you should be aiming to beat for it to truelly be ''revolutionary''.

Check out some formula one cars for inspiration, they have had some incredible systems over the years.

ORIGINAL: flacksaw

The reason it's revolutionary is simple...it's the first suspension ever developed where the wheel does not move in an arc

ORIGINAL: flacksaw

OK, hope you don't mind if I continue to develop it though....

The reason it's revolutionary is simple...it's the first suspension ever developed where the wheel does not move in an arc, it moves in a perfect plane. If you're unable to see why that's a big deal then I suggest you study up on suspensions. I was just sharing my invention for your interest. I've had some pretty experienced and knowledgeable people tell me that this is the ''holy grail'' of suspension designs. It really does approach the theoretical ideal for the first time. I'm sure of all those things and obviously, yes a lot of things need to be ironed out obviously but the VXI uses standard links and bushings just like any other suspension. You'll have to forgive me for disregarding the nay-sayers but I plan to develop and push this design until it's been put into production.

ORIGINAL: flacksaw
And lastly, the Provisional expired Feb 27th, we filed the official patent the day prior. If anybody wants to try to steal my invention they will get the pants sued off of them, I promise you.

ORIGINAL: flacksaw

Live axles? Really? You don't think they operate on an arc? That only happens when BOTH wheels encounter the same bump at the same time. Otherwise that ''dependent'' setup has horrible characteristics all around, you name it and it's bad. That goes for rock-crawling too where independent suspensions have always had better ground clearance than live-axles but haven't had the wheel-travel (aka ''articulation''), until now that is. The VXI gives you all that wheel-travel AND no track change. Really, go ahead and fully articulate your live-axle, measure the ''track width'' at rest, then measure it when articulated. It'll wind up being 1/3 to 1/4 what it is at rest.

ORIGINAL: Krawlin

If you are after the kind of travel you can get from a solid axle in a crawler, that's cool and all, but it will be unlikely to ever be superior to a solid axle for rock crawling.

There are several reasons why a solid axle is preferred for rock crawling, all of them reason's why independent suspension can't match the performance of a solid axle on the rocks.

A solid axle's ground clearance never changes, ever. If you have tires that are 6 inches tall, the center line from wheel to wheel is 3 inches above the ground. If your tires stay close to 6 inches in diameter at all times, the distance between the center line of the tires to the ground is still going to remain at close to 3 inches no matter what either tire does. Subtract a little bit for the diameter of the axle tubes and diff pumpkin, but you still get that ground clearance no matter what, at all times, no matter what either wheel does. If 1 tire goes up on a rock, your ground clearance is still the same, the diff pumpkin does not get any higher or lower from the tire's center, it stays exactly the same.

Here is the #1 reason why independent suspension does not work well for crawling and is much better for go-fast performance. With independent suspension, each wheel/tire can travel up or down independently of the other (obviously). Now let's use a Maxx suspension as an example here, since they have a diff pumpkin in between two bulkheads. As a Maxx approaches a rock in the path of 1 of its tires, assuming it is setup in the following manner, the diff pumpkin is above the center line of the tires, which from a ground clearance only standpoint, is great. But then 1 of the Maxx's tires reaches the rock, and that tire travels up the rock, peaks at the top, and travels down the rock, and the following rear tire does the same thing. Now what happens as the tire of an independent suspension vehicle travels over an object? Several things.
1. The truck slightly pitches as the springs on the suspension arms of that wheel compress as the wheel/tire travel up onto the object.
2. The tire that was once below the diff pumpkin rose up above the diff pumpkin, putting the center line of the wheels at different heights.
3. The tire then drops back down from the object as the truck continues forward and the wheels' center lines are once again even and below the diff pumpkin.
But here is the kicker... If you pause the truck's movement right as the tire was on the very peak of the object, then remove the object, and keeping the suspension of that particular wheel compressed, you place that tire back onto the ground, the center clearance is instantly extremely low as the diff pumpkin is now very close to the ground and the truck most likely pitched at a steep angle. Why? Because that particular wheel was allowed to move separately from the other, thus moving it's center line much higher than the other. Since the diff pumpkin follows for only a very short distance, you literally lower your center clearance instantly because the diff pumpkin can not stay between the center line of the wheels. In order to maintain the same ground clearance throughout a suspension stroke, the diff pumpkin must follow, and the only way to achieve this is via a solid axle where either wheel cannot deviate from the center line of the other. Which is why a solid axle will pretty much always be superior to independent suspension when it comes to rock crawling.


Now as far as a performance aspect goes, for go-fast kind of stuff, this setup is also undesirable.

Independent suspension is designed to have camber changes throughout the suspension stroke. It's what keeps the tire's contact patch in contact with the ground instead of moving the contact patch onto the sidewall, which is extremely undesirable and results in poor handling and many times a loss of control. Eliminating camber change throughout the suspension stroke completely defeats the purpose of independent suspension, basically making it worse for rock crawling than typical independent suspension. (Now as you know, a solid axle does not perform well, especially in the front of a vehicle, at high speeds in rough terrain and even on flat terrain. There are a few reasons for this, one of them being that the axle will not allow the wheels to deviate from the center lines of each other, resulting in excessive body roll and a considerable loss in traction because of the body roll ((lots of weight transfer from high amounts of body roll means loss of lots of traction)), and the other reason being the high amount of un-sprung weight which creates several poor handling characteristics. ) Allowing the camber change in independent suspension allows each wheel to maintain a much better contact patch, thus maintain traction. Another desirable thing about typical independent suspension is that throughout the stroke other variables besides camber can change and those variables can be tuned to change at certain points and certain amounts during the suspension stroke. Bump-steer (also known as a toe angle change throughout the suspension stroke), while often cursed as being a problem, is often times a very useful tuning variable and can greatly affect handling in corners. The change in track width is not something to worry about unless you have a suspension setup that allows for ridiculous amounts of travel and has massive changes in track width throughout the arc, and such a suspension would provide very poor performance in the first place. And scrubbing speed from track width changes would most likely be minimal and negligible at the most. You don't seem F1 cars running a suspension like this because track width changes throughout the suspension stroke do not scrub enough speed to even be noticed, and even in RC I feel this also holds true, it's so minimal that it probably would be hard to even record data of the amount of speed that gets scrubbed. Ackerman on the other hand does have a great effect on how much speed is scrubbed from a vehicle in a corner, as the inside and outside wheel travel through different paths, but as the suspension compresses, Ackerman changes, which is considered bump steer, which can be tuned and very useful.


To be honest, I think your setup is completely useless for almost all vehicles unless they don't do anything but go in straight lines (as in drag cars). And until it can be made MUCH smaller, the weight gain would do more harm to a drag car than it could gain from this suspension, and a majority of drag cars (top fuel, funny cars, etc.) don't have much of a front suspension at all really.

Kind of useless to argue about it anyway also, even though I just typed a huge post. It's obvious that this really has no benefits over typical independent suspension setups except for use in drag cars. There is a reason why an old design sticks around for a very very long time and even continues to perform better and better based off that old design... Because it's tried, its trued, and its been proven over and over again. When you consider the performance of an RC car compared to real cars, its simply amazing that they can do scale speeds of 350+ MPH (real life speed of 35 MPH) and take tight corners at scale speeds upwards of 150+ MPH (real life speed of 15 MPH). While the real life speeds may seem slow, for an RC to have that kind of performance really is pretty damn amazing when you sit back and think about it for a while. As the old saying goes, "If it ain't broke, don't fix it". In this case, that is 100% true. Do something revolutionary with a typical independent suspension setup to make it handle even better than the RC's of today, then we can talk about truly benefiting the hobby.

ORIGINAL: flacksaw

Oh, I read it alright, we just disagree I guess. You're stuck in the old-school ''nothing new is better'' and ''I hate change'' frame of mind. Change is inevitable, progress is inevitable and the VXI represents both change and progress.

Live-axles are the worst. The only advantages live axles have is that they're simple and cheap. The VXI will be winning rock-crawling and rock-racing events within 10 years, I promise you. Only then will the live-axle zealots like you be made to believe. I know where you're coming from and I've seen it plenty already but I don't think like you do, obviously. Fortunately your opinions are not going to stop me or the VXI from going forward and changing suspension design forever.

I could give you the laundry list of horrible characteristics inherent in a live-axle but you wouldn't believe me anyway, so why bother? Now, off to your ''I hate progress and change'' convention.

ORIGINAL: flacksaw
Live axles? Really? You don't think they operate on an arc? That only happens when BOTH wheels encounter the same bump at the same time. Otherwise that ''dependent'' setup has horrible characteristics all around, you name it and it's bad. That goes for rock-crawling too where independent suspensions have always had better ground clearance than live-axles but haven't had the wheel-travel (aka ''articulation''), until now that is. The VXI gives you all that wheel-travel AND no track change. Really, go ahead and fully articulate your live-axle, measure the ''track width'' at rest, then measure it when articulated. It'll wind up being 1/3 to 1/4 what it is at rest.