help to compensate for changes in the rack

I'm having problems with my houter, the rack I used doesn't have very good cymetry, in some points it measures smaller than it should and in other places it gets bigger, things 2 mm apart, mark all the points where this happens, I wanted to know if Is there any way to change the scale in real time of the machine, or something similar, like when it is in a coordinate where, let's say, the average is getting larger, you can compensate this downwards, to reach the exact measurements at which it should be, no. I wish I had to buy a rack new, would there be any way to compensate for these points on the rack?

Could mapping of the rack be possible as some do for ballscrews\leadscrews ?

Unfortunately I’m not really up on the implementation.

A few days ago I read in the manual this should be possible, You once do some measurements and create a table, and then you enter that table in LinuxCNC's setup. "lead screw compensation" (ball screw, or rack & pinion, or whatever is all the same for the software) is apparently a special case, you do not need customized kinematics because it's built into each axis.

I'm planning on experimenting with this. My idea is to add a glass scale temporarily along each of the ball spindles, and have a microcontroller measure the position at set intervals. Partly to check accuracy of cheap chinese spindles, and if LinuxCNC can add some correction, that's even better.

But I do wonder about your big deviantions. 2mm is a lot. I suspect your machine has mechanical issues.

Could you point me in some direction? or some topic that did this, I searched but didn't find anything

I've thought of everything, I haven't found any problem other than the rack, the engines aren't, I measured the entire structure with a dial indicator, nothing seat, I've recalculated the scales several times, everything is fine, the only idea is that the rack It came with a different space, as it is unique 
 
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