Spindle for Spool ROller

Line it up and keep both of the spool rollers straight and you should be good.
Print at .16 and it should be tap to fit. It's snug, but shouldn't be overly tight. It clears the parts on the spool roller nicely and it rotates smooth.

I found it easiest to mount one spool roller, tap this on and then fit the other roller. There's enough room on the remaining original spool holder to fit a stop mechanism if you need one.

If you want to adjust the size, you can find it here:
https://www.tinkercad.com/things/3FWm1dT6bRK