On the lowrider, the design of the wheel trucks have the bearings offset from each other. By that, I mean that the contact point of the near and far bearing are not perpendicular to the direction of travel. The combination of the front and back trucks counteract this twisting force so it isn’t a problem.
The question is, is there an advantage to this from a mechanical or alignment point of view, or is it practical so that the axel bolts do not interfere with each other? I’m using this concept in a different project, and currently have the bearings aligned with each other.
In the image above, the rail goes along the black line. The perpendicular line from the rail to the top bearing goes along the top blue line, and similar for the bottom bearing. The left and right bearing aren’t in alignment with each other.
The image above is my truck design for that sewing machine track. The bearings are in alignment with each other. The question is, is there any advantage to having it offset like in the LR or in alignment like mine.
The V1 bearings are arranged tangentially to the outside edge of the rail, and by definition they are aligned with the linearity of travel. They are linear assemblies, not rotational bearing assemblies.
The fact that the two included RS bearings are offset along the direction of travel has no impact on this.
Yeah, the benefit is in the packaging.
There isn’t any twisting force from bearing linear motion (as you stated in the original post.)
Not from the linear motion, but from the weight of the machine. One set of bearings (2 608s) in this configuration by themselves don’t have a balance point on the rail - the single truck will twist out of alignment. Two sets connected by a rigid plate will balance. But apply enough weight with some flex in the plate or trucks and the system will twist a bit. Since there is some give in the plastic, this built-in torque could have some sort of benefit (or consequence) to maintain connection or alignment.
I’m sure I’m over-thinking the design, but it’s akin to the way railroad wheels are designed. There’s always a challenge to construct strictly linear rails, so designs might exist that use geometry to adapt to imperfections.
