Couple of points;
The Igus site has a lot of stuff to calculate loading, spacing and alignment. I asked similar questions of Igus tech and got these answers amongst others;
Whatever rail you choose you will need much wider spacing on the bearings on each slide. These rails are not as forgiving as ball slides when it comes to racking miss-alignment.
Single rails should do the X fine from a purely load capacity perspective. Single rails mean you have to mount each bearing individually with the accuracy required.
Double rails would make the cost higher and require much more precise alignment. between rails. A benefit of a double rail each side is that the double rail comes with a mounting plate with the bearings already mounted on the carrage so taking care of some of the precision and probably giving a more ridgid gantry.
These (igus W) bearings have significantly different load capacities in different load directions. Might want to consider that, for example the Y axis might be better with the rails on different planes.
Andrew  |