I have a shaft and I was thinking it would be cool to make a custom fixture for it where it sits upright on its end and would be really easy to set up. I was thinking of making a snug fit that the end outer diameter fits into and include something that aligns with the shaft key way. The fixture would be bolted down to the fixture plate. My question is, since this would only be a snug fit (couple thou clearance or so), is that bad practice or should it really be held in place with a vice to really clamp it down? Picture below to see what I mean. In grey would be the shaft and in red the fixture with the keyway align. If this is a dumb design in general let me know haha. Also the shaft is decently heavy so I doubt it would be moving around.
as long as the artifact doesn't move, you'll be good. imho this fixture limits what you can check. i'd rather have both ends exposed so for shafts i tend to lay then down on the side and make sure it's balanced and enough surface area exposed so i can measure as much meat on the shaft as i can.
Yea I thought about the fact I would be losing part of the shaft esp since there is a runout that gets checked there, but I figured since its nearly 2 inches losing 1/4 of an inch wouldn't be a big deal. Only reason I wanted to stand upright is to fit more shafts onto the cmm and just knock out like 6 shafts at a time, hence the custom fixture idea.
Since runout is a surface to axis check then having lots of exposed surface is a good thing. Might want to check with engineering if the 1/4" on the end is more important than than the rest of the shaft.
Having said that a CMM often isn't the best choice for a runout check. You're very limited in data density unless you can scan or have lots of time to kill or have high tolerances.
