Aluminum router build - Could use some input

[Tumblebeer]

I've actually started building now. I won't really have time to maintain a buildlog here, but I am posting some status updates with pictures on my site/blog.
Currently got the main structure done, need to get the motors on there and a lot of fine tuning.

www.tumblebeer.com

The rails aren't binding, but it's not super smooth. Got any tips on how to alleviate that?

[routercnc]

The rails aren't binding, but it's not super smooth. Got any tips on how to alleviate that?

If the bearings are used they may need a strip-down and clean, followed by a re-grease - have a search in this site on how to do it and avoid loosing the balls!

But if they are new (which I think they are) they may need some grease.

More likely however is misalignment - how did you align everything? That wooden table does not look flat!
Which axis is not running smoothly X, Y, or Z? Most builders go to great lengths to get this alignment as good as possible including epoxy leveling prior to rail fitting (X axis, sometimes Y axis as well). Some builders use a DTI from a known flat reference surface, or a DTI from one rail to try and align the opposite rail.

Basically you have to remember that these types of rails are designed to be used by a professional machine tool design company and set up using machined datums etc. Have a search for the Hiwin fitment guide (either here, or on their website) to understand the lengths they expect the machine tool company to go to. You need to spend time on the alignment as best you can to get these running smoothly. As a start you can loosen one of the pairs of rails, run it back and forth, slowly tightening the rail bolts again. If this doesn't help then you may have a twist problem on the mounting surface. You may be able to help this with shims but I think you are better off getting the surface machined or epoxy levelled.

But do persevere with it because once set up accurately these units help give you a really high performance machine.

Well done on the actual build. I wouldn't have made all the design choices you went for (unconventional Z axis!), but I will say that you've made a good job of turning it into something real and that in the end you have ended up with a pretty capable machine.