thank you! 
brilliant moments, for those who don’t watch far enough in.
5 Likes
Awesome video. I simulated the 3 links in CAD and also found the axle path to be a straight line, unless the linkages were made so short that the axle actually rotates as the truck turns which produces that S shape travel but only slightly
2 Likes
That article is hilariously ignorant. I hope he gets on a board with 3-links and puts the pieces together for himself.
I briefly attempted to model it up in cad, but I’m not good at the whole motion study thing yet and have on more than one occasion designed a truck in Cad expecting it to perform one way only to find my model I was basing my assumptions on in cad was Incorrect!
It would be easier to explore in cad, to do whatever experiments virtually by changing a few parameters.
But even then I would still have wanted to run this physical experiment to verify what I saw in CAD lines up with what I see in real life. Because you’ve got to do reality checks. I mean, in my video at least three times I suggest something is happening one way only to prove myself wrong seconds later.
I really should give a exploring this in CAD another shot, but I’m actually just not quite sure how to approach it.
3 Likes
Yeah its amazing how trucks are so simple in principle yet in reality they can be so complicated because changing the shape of a bushing seat by 1mm can have a noticeable impact on handling.
The way I modelled it was just by creating a bunch of sketch lines as separate components and adding joint relations between the points at the ends of the lines to recreate the trucks and then I was able to just drag the components around and it would all move properly. And then I’d adjust the dimensions of the lines to see how moving the position of the radius rods and mounting points and stuff changed the axle movement.
But I pretty quickly concluded it moves like a normal truck so I’m super keen to try these trucks because people speak so highly of them that I wonder if something else is going on that makes them better, besides the precision and effective baseplate angles
4 Likes
I see. Detaching one of the links would allow the axle to twist, messing up the axle travel.
What if you attach it differently. Like this (yellow) instead of the usual way (green)?
I mean connecting the spherical joint is directly to the axle instead of going thru a collar. Axle twist may no longer be an issue even if only one of the links is attached. (I dunno what I’m talking)
2 Likes
maybe im tripping, but wouldnt it be unable to move at all if connected like that?
this is closer to how changing(d)angles modeled it. which of course is… impossible. 
3 Likes
I’m saying that once you have linkages like that on both sides it’s gonna be 0 dof, no?
1 Like
You’re right it will move but also the whole axle can spin which is no good for motor mounts
1 Like
would it move with both the linkages on? ill model this later and have a look but for some reason it dosnt seem like it would be able to move really at all with both sides connected. hm maybe im just stupid…
3 Likes
if you do both sides like the yellow. then you have what changing angles modeled. and I don’t think it will move.
1 Like
Make two finger guns, place folded knuckles against edge of table, pick up a pen and try moving the pen around. it can’t be fixed in the middle.
In this illustration, right turn and left turns will have changing steer ratios on a curve that do not parallel right to left.
Meaning, ratio increases in left turn as rod angle increases and decreases in a right as angle decreases.
R to L turn angles without a parallel plane that changes steering curve and ratio as angle is reduced or increased.
5 Likes
IMO, its actually pretty cool idea to have a truck with asymmetric turning progression.
Certainly heelside/toeside turns aren’t anatomically the same.
I’d try it for sure if it was an easy modification.
4 Likes
Asymmetric boards in general are underrated IMHO.
Do you think we will see the 3 link designs trickle down to consumer boards? Too complicated?
2 Likes
One of the features we played with is the ability to change heelside and toeside rebound and preload. Not what you are talking about but helpful dialing in heelside turns.
@fujio001 my door is open.
2 Likes
Damn, thats interesting.
My toeside has always been dominant and can easily apply more leverage.
My initial thought is it’d be as easy as putting my healside link at a ateeper angle… how naive 
.
Following thoughts has it much mire complex than that.
Being a spherical joint it would take a split duro bushing on the equator of the joint to pull off asym rebound. Channels would be much easier to test on
4 Likes