Why does nobody talk about how much backlash matters on older HAAS mills?

I was reading through a service bulletin from 2018 the other day and it mentioned that a HAAS VF-2 from the early 2000s can have up to 0.005" of backlash in the X axis just from normal wear. That's basically a whole tolerance band on a lot of the parts I run. I always thought it was just a tiny thing but now I'm wondering how many jobs I've messed up over the years without knowing. Has anyone else checked their backlash recently and found something surprising?

3 comments

3 Comments

dylanwilliams1mo ago

Funny how small stuff usually adds up way bigger than anyone expects.

ryanburns1mo ago

Yeah @dylanwilliams, I once found 0.007" on my VF-3 and it RUINED a whole batch of parts before I caught it.

ruby_lane1mo ago

Thought I was fine too, until I did a ballbar test on my 2005 VF-2SS and found 0.004" in the Y axis that I'd been chasing on some close tolerance work for months. Realized all those little .002" oversize bores I was blaming on tool deflection or material shift were actually just the machine lying to me the whole time.