If you are installing a pin and there is run out then the joint becomes an oval instead of a round.
Now match a shaft to that oval joint.
OK ... so you sand it to match and as long as the shaft dont wear and screw on a bit further or if you never need to face either side then I guess it will do.
I try and get the pin as close to dead center as I possibly can and that usually requires shimming or adjusting the tru-set part of the chuck.
Willee
Yeah very familiar with what You are saying, so I'm with You on that, and kind of why I was asking, the cues I refer too don't have major issues with egging, looking down the barrel of the shaft face also looks perfectly centered, and can't feel no egging when the shaft is spinning. sure I hand match them cause I don't use carbide mandrels yet, but the amount of difference doesn't seem to even add up to what I would think. If the shafts were not finished turned off the butt for example, but say they were turned between centers all the way to final, then It still seems to come in under the amount the indicator showed. Such a small amount that the finish alone could make up the difference without thinning the finish cote out too much on one side. It doesn't seem to be enough to even hardly register once the faces seat either. a little bit of work on the high end of those #'s, but yeah the lower the less. That's sort of the point of My question, most cues I see, the good bad and ugly, don't come near that close, although there are a few exceptions that do, and for good reason (the makers did flawless work) but even then I would say the comparison is real close. When I shim with crate paper to get under .001, yes that is especially true as one would expect, but even the others that I mentioned before don't seem too much different.
Matching those shafts I would compare to a ferrule job, that is so close, that no file is needed to knock any high side down, and a quick, lite, hit with 600-800 is enough to perfectly blend with no need to go any coarser. Could almost be buffed out depending on how you go about It. I could hardly consider that too far off when I see so many other cues that don't come close to that even after finish. Same issues you mention is what I see in those.
Anyway I'm not trying to argue the fact of what should be acceptable, so hope that's not the way it sounds, I'm with anyone 100% when It comes to "the closer to dead nuts the better", and I strive to go as low as I can go with what I have like anyone else, but that's been trial and error over the years, started out at around .005 on my first, and worked my way down to under .001 that's as low as My manual indicator reads with out hitting zero, and seems to be close enough for me. I'm really just more interested in an honest number of what people think is acceptable, not what they hope to get someday (that's a given we all want to bottom out dead on), but what they have to live with even after their best attempts to shim or what ever It takes to get lower. Sometimes, I'm confused at the numbers I hear, and wonder which are just muscle flexing and which are for real. I think if people were honest we would see a variety of numbers, some will be lower yes, but some will be higher, maybe somewhere in the middle could be considered acceptable ground.
Again basing the number off of a sp or cue that costs well under $500 like what was mentioned in the thread as that's what got me thinking about It. Not saying someone should not put their all into every cue, just that for someone starting out, what's acceptable for them may be in the .002 range. Realistically I see a lathe like this being used for those purposes, even someone starting out building a few sp's, or maybe even as a repair lathe for someone that already has a lathe to install pins, and other stuff. My comparison is to similar lathes though not this particular one. Multi purpose.
This is the way I see It for someone starting out, .004 or higher probably not gonna be happy .003 not perfect but can make It work (like you said depends on what you can live with, but that's a bit to live with), same goes for .002 but with better results and a bit easier to swallow, under .001 real easy to live with, and should be happy if getting those #'s early into the game or on the lighter more affordable equipment or even some metal lathes for that matter.
Took a lot of work, but I did get one down to .0005 before setting a pin, and was very happy with that, I can't imagine needing better, although that would be nice. when I hear people that seem upset, over trying to achieve better then that, I wonder if It's even possible to hit dead nuts, once You get down so low, doesn't the irregularities in some of the materials account for some of that? My point is It doesn't seem to matter what repeatability we get with a ground bar to indicate off of, can't that be different when we indicate off of a joint, and can't the type of material account for some of those minute numbers? I mean .0002 that's freaking insane in my world:grin:
it gets Me in the ballpark though, and when It comes to how close the shaft matches, and how straight the pin seems to go in, I guess at least I know where I stand from what I read with It. I do need to upgrade to something better though. It's possible the numbers I quoted could be lower on a better indicator, as I'm only going on what I read on the one I use.
