Need Help!- G08 look ahead

[philnsam]

we are buying a Tsugamii horizontal with a Fanuc 18i control and I'm
looking into options to be turned on. I am looking for the difference between
G08 look ahead and G05 hsm. To me they both do about the same. I have
G05 on a Makino S56 vertical mill and my understanding is it looks ahead in the program and then adjusts the feed during any contouring as needed to
make a smooth transmission between comands.

[psychomill]

G8 and G5 are not the same.... The general purpose is the similar but the capabilities are far different from each other. G5 also has more than one version depending on the option chosen and software/hardware being used by the machine.

G8 is a good general lookahead that can advance your feedrate ability and can improve accuracy do to the look ahead function. It's also the most nimble lookahead commands that doesn't have very many restrictions on how it's used, when to use it in code, and has many codes that can run like cutter comp, rotation, etc, etc.

G5 has a far greater lookahead and but has more restrictions for when to activate and what other commands can be active. It's designed around micro segment programming. Newer versions of G5 have improved this by allowing more commands to be valid and also allowing for better precision control by way of adjusting "sensitivity" so to speak which can be commanded in the program. (EX: G5 in roughing: set for speed. G5 in finishing: set for precision).

There's some better docs out there that gets into this with better detail. I'll post the links if I find them. IMO.... get the G5 option (need to figure out which G5 is being offered and decide which you want). G8 should be standard on Tsugami I would think? With G5 option, you should have both that and G8 as well....