anti-squat and parallel links

[setecastronomy]

Ok, I read lods of stuff about 4 link suspension and I learnt about the Instant center and normal line. I have a doubt on a specific setup and I ask for help. Consider the case of parallel links: the IC is at infinite in the same direction of the links. In my crawler with half droop my links are horizontal at ride height, so the IC is at infinite distance from the front of the vehicle. Tracing a line from the contact point of the back tires to the IC I obtain a horizontal line which coincides with the ground itself. In fact the IC is on a line parallel to the ground at a very great distance, so it can be seen from the contact point with an angle which goes to zero.
So the normal line intersect the vertical line from the front axle at zero height and the anti-squat should be 0 %. This is what the theory says as far as I know. Unfortunately I can assure you that this setup is quite good and I cannot believe it is a 0 % anti-squat because my crawler doesn't squat at all. Where is the mistake ? Perhaps am I using so hard springs my suspensions cannot move ?

Thanks
Filippo

 

[setecastronomy]

Is it clear what I asked ?
If it is not express your doubts. I cannot believe nobody knows what happens when links are parallel.

Bye
Filippo

 

[ADDICT]

The upper links being non-trangulated is what i run personally. Very great set up imo. Front and rear. Anytime you can get the upper links closer to the lower links you will have a advantage. Less tourqe steer and the articulation is perfect. Try posting some pics you might get a little more input, good luck"thumbsup"

 

[4RnrRick]

Parrellel link setups are really impossible to tweak and tune... I would suggest a more traditional converging link setup like a double triangulated link setup that you can calculate the instant center and roll axis of the link geometry simply and with minor variations too (2) link mounts, can totally change the geometery.

BTW and AS value of 100% theoretically means the suspension with be neutral, it will not raise or squat on take off on FLAT ground.

I'd suggest reading up here for info on 1:1 rock crawling link suspensions. Links taken from Pirate4x4.com Toyota FAQ.




Link suspension info
The ultimate listing of the most important link suspension posts.......

THE GOD OF SUSPENSION...[for those of you who don't know]
http://www.pirate4x4.com/forum/showthread.php?t=7503

LINK SUPSENSIONS FOR DUMMIES?
http://www.pirate4x4.com/forum/showthread.php?t=168577

New Version of my 4-link Analyzer & Request for Help
http://www.pirate4x4.com/forum/showt...hreadid=204893

ExcelCAD - Awesome Link design Program
http://www.gregblanchette.com/pages/1/index.htm

 

[setecastronomy]

So I made lots of intenet searches during my working time (my boss is quite irritated about that) and I found some pople say that having parallel links (on the side view) is not good because the anti-squat is very low or near zero. It can be seen in the following picture where the rear links have a small angle with the ground and the anti-squat is near zero and tends to zero if the links are both parallel to the ground.

Unfortunately for this theory I ahve a setup which is almost identical but I cannot notice the rig to squat. Perhaps there is a mistake somewhere in my reasoning.

Bye
Filippo

 

[Robbob]

I dont know if you have seen this thread but theres a lot of useful/helpful discussions on link positions.


http://www.rccrawler.com/forum/showthread.php?t=54791&highlight=antisquat