Whats about making a 19 LDU (or whatever is the correct length) primitive with rounded end on one side and another scalable 1 LDU long primitive without ends?
Combining just 2 of the prims with rounding end will result in a 2L axle and the use of the scalable prim in the middle will give us the opportunity to create all other lengths of axles.
With the short one we can also model other parts like short axle pins, bricks with axle etc.
Maybe we can even do an even short version with rounded end, which can be used for the 2L notched axle and in the 19 LDU long prim.
BTW what will happen, if we create the rounded end prim in die \48 folder and another one without rounding in the prim folder? (Yes, it's a misuse of the \48 folder, but this will result in faster rendering, when "48-substitution" is not activated.
Combining just 2 of the prims with rounding end will result in a 2L axle and the use of the scalable prim in the middle will give us the opportunity to create all other lengths of axles.
With the short one we can also model other parts like short axle pins, bricks with axle etc.
Maybe we can even do an even short version with rounded end, which can be used for the 2L notched axle and in the 19 LDU long prim.
BTW what will happen, if we create the rounded end prim in die \48 folder and another one without rounding in the prim folder? (Yes, it's a misuse of the \48 folder, but this will result in faster rendering, when "48-substitution" is not activated.