Are all classical guitar tuning strips the same size?

Luminous

Or is it a minefield....

octatonic

There are a couple of different sizes.
I'm not a classical guitar guy but I've replaced a few which had a 35mm spacing between the rollers.
That is what you need to establish most of all.

Have a look here for a diagram of the typical spacing.

http://www.stewmac.com/Hardware_and_Parts/Tuning_Machines/Classical_Guitar_Tuning_Machines/Schaller_Classical_Guitar_Machines.html

Luminous

Thanks boss

AliGorie

yeah 35mm is pretty much the standard (if your guitar IS 'standard')
here 34.9 - near enough.
also be were - the string roller dimensions particularly the diameter - on this example 9’86mm - to big and u’ll have to ream out the hole to small and there u'll ‘play’= tuning stability probs.

FelineGuitars

on smaller sizes you need to use individual tuners like the Schertler
http://www.stewmac.com/Hardware_and_Parts/Tuning_Machines/Classical_Guitar_Tuning_Machines/Schertler_Classical_Guitar_Tuning_Keys.html