oau, i forgot this thread

in production time is money and a reamer will save time every time
all these are frequent aspects :
... tool costs, especially non-standard sizes
... tool delivery time
... setup time ( alignment, tir check, etc )
... adjusting cutting specs
... holes that are too big /too small, even if the reamer dimension is ok
... almost no chips at all, on a machine that is capable of delivering chips

what about improving all these aspects ?

That would be my first go to tool for a hole solution...…...alternatives go down the more time and less accuracy ladder.
please, what alternatives exist, and why are those with less accuracy ?

Reaming after drilling also is not an answer as the reamer will just follow the drilled hole and that can be out of position
the reamer is not always following the hole; each setup is a balance between elastic & plastic deformation

for a reamer to follow the hole, then the elastic component has to be dominant, alowing the tool to 'move' inside the hole, and shift back to it's original position, when it is out of the hole

for a reamer to not follow the hole, the plastic component has to be dominant; this can be achieved, for example, with a rigid spindle + short overhang tool with long flutes

each machine, in time, increases it's elastic behavior, thus is losing rigidity; for a process that delivers tight tolerances, then this effect has to be postponed as long as possible


what can be done ? analyze the frequency of the holes, and dimensions
... get a set of after-drilling tools ( they look like a reamer, but with less flutes, and they are more rigid then a drill; the trick behind such tools is that they don't copy the hole, and can straigthen-up a tilted hole, delivered by a long drill )
... get an attachement ( eccentric boring or grinding attachment, honning attachements )
... put that attachement on a ' normal ' machine, and leave it there : voila, this is a low-cost specialized machine, that never runs roughing operations, spindle is not under frequent tool changes, etc; like this, the machine keeps it's accuracy for a looooong time
... get a specialized machine

i don't say that a reamer is bad; i say that controlling costs and analyzing downtime requires patience and time, and seeing such alternatives in action may help / kindly