Just wondering if anyone has a simple rule of thumb on how loose or tight one might tighten the trucks on freight cars.
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Originally Posted by mike g.:
Just wondering if anyone has a simple rule of thumb on how loose or tight one might tighten the trucks on freight cars.
Maybe it's just me but, I have always tightened one truck so that it barely turns freely, while the opposite truck I leave a bit looser.
Tight enough so the cars don't rock and loose enough so the trucks easily swivel on curves. Also if negotiating rough trackage so the wheels don't lift with rigid frame trucks.
....... and I have also used the technique Hot Water just described.
Originally Posted by Hot Water:
Originally Posted by mike g.:
Just wondering if anyone has a simple rule of thumb on how loose or tight one might tighten the trucks on freight cars.
Maybe it's just me but, I have always tightened one truck so that it barely turns freely, while the opposite truck I leave a bit looser.
Yup. That's the ticket.
I use Hot Water's technique if the trucks aren't equalized -- basically equalize the car. Works pretty well so far. By the way, that's a good thing to do even with hi-rail trucks.
Im guessing it affects how much the car stays on the tracks? I'm changing some out and don't want to have to fight cars derailing.
The idea of tightening one truck so it just turns freely and leaving the other able to rock creates a three point suspension on the car. Often people put a spring on the looser truck that still allows it to rock, but not flop.
That way the car can adjust to rough track. The rigid truck is short enough to follow the bumps and the floating one means the other end can also adjust to dips and sways that the first end makes.
The best thing is to have equalized trucks and allow them both to be tightened. However, a lot of trucks don't equalize or at least not enough with the weight of the car. Atlas are a good example. The trucks are sprung and theoritically equalize. But the springs are very stiff not allowing the side frames to move, and the structure of the two-part bolster further restricts any movement within the truck. Essentially they behave like fully rigid trucks.
Athearn trucks and Weaver trucks are nicely equalized in my experience. Athearn are sprung to accomplish equalization. Weaver trucks have side frames that rotate slightly on the bolster on each side to accomplish it. Both work very well that way.
Great advice thanks guys!
"The trucks are sprung and theoritically equalize. But the springs are very stiff not allowing the side frames to move, and the structure of the two-part bolster further restricts any movement within the truck."
I've also found sprung trucks that are sprung too tight against an un-even bolster surface so they tweak into a three wheel on the rail configuration..DaveB
