Electric active rollcentres
 

Would this be classed as active suspension in the brca rulebook ?
Would it be beneficial on track?
Cheers

Schumacher used to have SACS on the front of the 'blade', so unless things have changed, it should be ok (as long as it isn't externally adjustable).

Sounds cool!

Good to see Rebels workshop is open for business again ! :thumbsup:

Sorry I should have explained further:)
Roll centres that move (powered) when car is steering, then alter for the straight .

serpent did this for thier on road cars http://www.serpent.com/news/13127/US...LS-system.html

not sure if it would work for off road

If it is changing the suspension points then, i think, it would be classed as 'active'

Cheers guys
Isn't active suspension classed as reacting it's self ,to change on track

That's cool Mark
I didn't know of this serpent kit
That's the system I've been campaigning for years lol
It's actually a system called camber compensation designed and <patented> by Dax sports cars lol
Should work very well in offroad low grip conditions, do you think?

I think the rule that people are chatting about is this

So, unless you are using sensors to control damping or suspension geometry and it is a passive system, like SACS on the Fireblade, then ok, the rule was brought in after the 1991 Basildon worlds, with LRP's system which used a gyro and rpm sensors to control wheelspin and steering angle of the servo.

Cheers DCM
So no sensors, no extra servo = legal
Perfect , should be very simple
Many thanks

The way I read it, as long as it is passive, and can not be controlled externally or 'programmed'.

Cheers Steve
By that do you meen, once on track cannot be altered?
Thanks for you help on this mate:thumbsup:

Well, you can adjust all your suspension off the track, on the track you can't.

Going by those pics. I dont think it`ll be effective. From what i can see is if the outside wheel raises up it then pushes down on the inside wheel. Which in turn will lean the car even more to the outside of the corner. In my opinion not what you want..That is unless i`m missing something i wont be doing anything like it on mine.

in the damp/wet it gave amazing grip (i had a version for my xray from Arena rc)
yup dax and there are some vids on youtube of it working on rc

metal, not quite, it does not push the chassis, imagine your wheels are on the flat suface, pic up the front on car and roll to left and right, the wheels will both remain upright with your 1 degree on them, its does not effect shocks/springs (though set up can be changed) simply camber links, it worked so well in the damp with ic as it car max contact patch on any chassis roll.
if you put the car on a flat surface and pushe the chassis up and down its as any conventional suspension, where the wheels do what they do without, its only on chassis roll and on one wheel deflection, in ic on road you remove any roll bars too of it numbs the effect!

these may help

http://youtu.be/5qtu--vh5wc

http://youtu.be/DYjfUyddUkQ

http://youtu.be/VYDuSdeKn-8

It doesn't push down at all. There is a link attached to each wishbone, but they aren't connected to each other in any way. As the outer suspension compresses when cornering the link pushes the pivot arm the opposite upper link is attached to, which pushes the upper link outwards causing the inner wheel to stay upright as the chassis rolls, or even lean into the corner. At the same time as the inner wishbone drops due to chassis roll it will pull the upper link of the outside wheel inwards, increasing the camber of the outside wheel. It keeps both tyres flatter to the track surface compared with a normal setup.
It means you can run longer/straighter upper links for more traction, but when cornering the links pull both wheels into the corner for more grip.

Useful on road with a fairly constant ride height, but would lead to some very odd handling off road as each time a wheel hits a bump it will push the top of the opposite wheel outwards leading to rapidly changing camber angles.

The receiver should only be used to supply power for the third channel, usually this is for your transponder. If your system can work off a battery without being connected to any of the radio gear then it would be legal.

the tekin rc10 mid motor car had this

Cheers Dave
I've never seen that car before
Very interesting

The Tekin chassis was also the first race buggy mid motor conversion as well - over 20 years ago. It shows just about everything was tried years ago.

The Tekin system is different to the Serpent one. The Tekin has both upper links attached to a single sliding mount so as the suspension moves straight up and down it has no effect on the upper links, while the Serpent design will move the wheels in and out. The Tekin design has less effect when wheels go over bumps, but will still pull the wheels upright when cornering.

invented this around about the same time as Dax.
A little different as you can see. with the use of a Watts linkage.

http://i471.photobucket.com/albums/r...IMG_0884-1.jpg

http://i471.photobucket.com/albums/r...8/IMG_0885.jpg

http://i471.photobucket.com/albums/r...8/IMG_0886.jpg

INcorrect, as i have posted when the chassis goes up and down the wheels do NOT alter thier angles (providing both arms are moving)

http://www.youtube.com/watch?v=h73MC40VPsU

http://www.youtube.com/watch?v=11xXhxjZQeA


hard to explain but when you have seen/used it in action its simple

..which is different to a standard suspension setup where the wheels will lean in due to the fixed upper link attachment. The Tekin system replicates a normal suspension under straight compression. The Serpent system moves both upper link attachment points outwards as the suspension rises which if it is adjusted right can keep the wheels vertical, but it isn't the same as what happens on a normal suspension.

I would like to see you demonstrate the Serpent system keeping the wheels vertical over the sort of wheel travel a buggy has, not just the rather short travel of a nitro on road chassis.

Can I also point out that the first video link you posted demonstrates the chassis in roll, but never actually moved the chassis vertically to back up your argument. :p

I spotted one here tonight.

This is the Dax system
http://www.daxcars.co.uk/start.htm

And the way a Wheel leans in is due to a compromise for corner grip on linkages
My other vids do show up and down

A Different Approach
 

Heres my system fitted on to a Losi 22. The rear shock tower pivots in the center and is driven by the servo which is on a Y lead with the steering. As the steering turns right the left shock is compressed and the right shock is lifted , and vise versa for steering left, taking out the chassis roll. It works very well, it may not conform to brca rules but at club racing it does'nt matter

That's pretty cool, I'd love to see that concept in action!

Interesting execution of that idea. How does it deal with heavy offset landings?

Also, would it conform to BRCA rules if it didn't use a dedicated servo (ie. if somehow driven by steering servo), or is it simply a case of powered as opposed to mechanical not being allowed?

dont we rely on chassis roll to load the outer front wheel for steering?

looks like its ok in the rules. (the variable camber ones)
As far as 'is it any good on track' goes, I be interested to know.
It has obvious advantages for on road.
For off road i guess the biggest thing would be having more suspension travel on the outside cornering wheels because the lack of roll. Wether its an advantage overall I have no idea. Would be interesting to hear what the experts have to say.

The impression I got when I made my little prototype 20 years ago was that it would be very difficult to make ajustments. Every little change has so many effects. Just figuring out what the roll centers are doing boggeles the mind.

think im right in saying the serpent one does not rely on roll centres as the wheel is allways at the set camber and tyre is flat on the track

Interesting, I've been thinking of doing something like this for a month or so now... Great to see it actually works then!

Just wondering though, what happens if you make the system such that it rolls into a corner (like a motorcycle) instead of just staying level? :confused:

surely it would be better to move a mass inside the car such as the battery towards the inside of the corner to stop it lifting than to alter the suspension at one end of the car only. it worked on an old rc10, so surely it would work on a modern car given enough space inside the car to allow a pivoting tray to be fitted

The real effect
 

The real effect of the serpent and tekin designs is a live real axle. Exactly the same movements. Only benefit is you could build a set up somewhere half way. Might be better for on road but off road a system that lets the car roll in the corners for grip, then stabilizes the car on the straight might work better?

If I read it right, and only to confirm with those above, as long as the system is passive (ie not controlled by remote connection or force) then it is ok to use. Passive in motor sport generaly meens something acting on something else by meens of a natural force...not mechanicaly driven or forced by motor or similar acting unit.

The LRP unit back at the worlds all them years ago was a classic 'non-Passive' unit. As mentioned the giro and ESC along with a sensor on the front wheel (i believe it was the front) was used to see if the car was tailing out or spinning the wheels up. It then reduced RPM to steady the car. You can imagine the uproar it caused, though I dont believe it won the event (it may have been banned during the event if i recall).

So, in short yep the push rod system as seen on that serpent car would be legal, as would other push rod systems being passive.

Really neat and good idea :thumbsup: , but BRCA illegal :thumbdown:

Top work though, it looks bloody good

just out of curiosity, if you were to do away with the servo and just had the shock tower pivoting would that not have a similar natural effect, might be the cider:thumbsup: talking but just a thought :confused: