Luthier CNC

[bluesking]

Well Fred's kit is the real deal so you don't need to worry about it being fake Hiwin linear rails and bearings, the fake stuff doesn't move as smoothly as genuine Hiwin dose, Hiwin is usually quieter as well.

Don't forget to clean them and give a few drops of oil, once everything is setup and running great you can start using Lithium 2 lubricating grease, this lasts longer.

Thanks Lee. I had a go at aligning everything tonight. Definitely improved. Shimming made a difference but still something a little sticky at the extremes. I then tried relaxing all the various attachment points for the ballscrew but this didn't make much difference. In the end I relaxed all of the big 12mm screws holding the 3 main extrusions. This made a significant difference but if I tighten them all up as tight as I can there is still some binding. In the end I tightened them quite gently and this reduced the binding at the extremes to very low levels and the overall frame still seems very rigid. I'm still concerned its not exactly perfect!

I don't really understand what you mean by moving the mechanism with one finger. Certainly pushing the gantry, it doesn't move, there is enough friction to stop any linear force from being converted to rotational motion. For the vast majority of the travel I can just about turn the pulley with one finger - is this what I should be looking for?

I do have a dial calliper and stand but very few places to attach it and not really enough skill to use it. I think I'm going to have to just move on and hope - without any experience it is hard to know if I'm facing real problems or just being picky!