This would work well until the chrome started wearing as aluminum is a very soft metal and bearings are very hard it would start scoring very at minimum I would use tool steel
aluminium is a horrible choice for a cnc machines linear guide shafts, unless you are planing to never mill hard materials like, wood, plastic and metals.
printing the linear bearing is also a bad idea, tolerance need to be tight and you want it to slide smoothly without the “stick and slip” effect else your servo or stepper motor has to waste extra torque just on movement alone.
the second option makes more sense, and get a good quality shaft which is suited for the job.
yeah I figured I fucked up with choosing aluminium… it was just to easy to obtain. In my case, CNC will not be milling stuff, it’s more of a pen plotter really. I’ll attach a pan to it, it will draw on a paper, that’s all. I wonder when aluminium will wear off though, how long will it take.
Yeah my bad… going with aluminium was stupid. I’ll get steel ones, they are just harder to get, I did not want to use amazon for that, as it was very expensive for some reason. How long will it take till aluminium wars off btw?
It is good design, for a sleeve-type bearing setup, for the bearing to be softer than the slide/rail/shaft. This way, the bearing wears out before the shaft. This would be the case for either of your options, but I presume option number two would lend itself to a quick swap of a sleeve should the bearing wear out. So, I think option #2 is good.
Also, as for material, aluminum isn’t necessarily bad if it is appropriately sized for the intended use. You do not want to run ball bearings against aluminum, no, but for a sleeve type bearing application, plated aluminum is fine. Chrome is good, anodize would also be good. The plating protects against oxidization and provides a hard surface to resist abrasive wear.
