Quote Originally Posted by Husky1 View Post
i am using 15mm tbi motion linear rails on the gantry. I have changed my setup 6 months ago, moved leadscrew too high above the linear rails. I am always pushing my machine to the limits of the spindle (3000mm/min, 2mm wall, 15mm deep, 10mm endmill). I think this was the cause to wear them. I didnt have any issue before the change.

I am changing gantry rails now with 25mm, and putting leadscrew between the linear rails. Considering buying 6.6kw hsk63 spindle.
TBI are decent enough linear rails and I still wouldn't expect them to wear out like this, also those cutting parameters while at the limit of the spindle shouldn't be anywhere near affecting the linear rails.
If the machine cannot handle 2.2Kw or 3Kw spindle then it certainly won't handle a 6.6Kw HSK63 spindle and just fitting larger rails may not be enough. I would look carefully at the machine to see if can find any other cause for the rails wearing out in that manner because I'm pretty sure it's not just because you have moved the ball-screw position. That large spindle will quickly find any weak areas and you could be back to square one chasing issues.