Hello I am building a Prusa i3 rework for my brother. I printed the parts in my core XY printer. I used the parts listed here: [www.thingiverse.com]
Everything fit perfectly in y axis but I have a problem with X carriage, motor holder and idler.

The carriage moves smoothly 1/3 middle part of the rods but it has friction as it get close to motor holder and idler. The rods are getting closer at the end.
The holes for rods should be 1.5mm more apart as far as i can see. I am not sure if the problem is rods or printed parts.

It can work with this i think. But is there a way to correct this ?

1.5mm is way too much difference.
When I was looking for replacement parts for my Sintron Prusa, I tried the rework parts and they didn't fit either. It's a shame they didn't correct it since 2013....
I then printed the Sintron parts ( also available on thingi )

Thank you. Will those parts will be in alignment with z motor holders? Should i change them as well?

Strange, looking at the linked stl's, the hole spacing looks to be fine on the X carriage parts.
Maybe worth taking one end off(idler end) and just check your rods are not bent.

I also took a look at the stl's. The two X ends align fine.

So the issue is elsewhere...

Any of the following...
bent rods
skipping Z steps while printing
Bed with thermal expansion issues

roll your smooth rods on a milled flat surface like a table saw top - do they roll without gaps?

I checked the holes and found the problem. The x carriage bearing beds are nearly 1.5mm more apart than the holes in the x motor and idler.
I searched thingeverse and found an alternative x carriage. The designer put two alternatives. The first one worked for me. Now x axis moves
perfectly smooth.
I used this one:

[www.thingiverse.com]

Thanks for your help.