How has anyone checked the "trueness" of an Algn shaft with the integrated bearing stop collar for trueness. Without the collar I would simply roll the shaft on glass.
Not sure how to check for subtle bend with the collared main shaft.
Two pieces of glass, run the collar down the space between. If the underlying surface is uneven you may get a gap between the glass and shaft at some point, but as long as there is no wobble to the gap it's all good.
