pete wrote:At an average .045" wall thickness Harold that's a work holding problem right there without the going out of round issue.
Indeed! You have to be creative. The part was driven by light pressure, held with a live center pressing a center plate. The plate fit the existing bore.
I learned, right off, that the part would not be stable until it was fully machined, and being a rolled and welded tube, that was a bit of a chore. Multiple passes of light depth were taken, with coolant running continually, to keep the part cool. The first time I got it right, it went out of round in polishing, so I reverted to flood polishing. A real mess, but highly effective. I'm proud to say the tube turned out beautifully.
I can see where a lot of experience had to be used to get working parts at the end.
I learned, long ago, that you must have a big box of tricks from which to pick, and having extensive experience in difficult work is a definite asset. When I ran my commercial shop, I was well known for tackling difficult work, which I attribute to the good work ethic instilled in me by my savior, Jay Dobson. A finer man I've never known.
Garys analogy about what makes a real craftsman is a great one and something I need to remember. On any job I've worked at the people who really enjoyed what they were doing were almost always the best by a noticable difference.
Absolutely! You can generally tell when a guy has "the gift". He works differently from others, and takes great pride in what he does. I worked with one such individual- a guy from South America. He was heads and shoulders better than all other lathe men I've ever known. If you messed with his machine (like changing the compound from 30° to 29°), you heard from him, and it wasn't polite.
You can often tell who has made parts simply by looking at them. When they are nice and uniform, good finishes, consistent sizing, you know they've come from one who is concerned about details and takes great pride in what they do. However, in today's CNC world, unfortunately, that is no longer the case. The dolt who has little interest in quality can turn out work equal to that of the guy who cares, because the machine doesn't know the difference between one who does, and one who doesn't. Both of them push the same button.
If your not producing commercial parts where that time is money problem shows up, then sometimes striving for more accuracy than what's really needed can be part of the hobby as well.
I've had that discussion with several people over the years. I truly believe that if one trains to work precisely, it takes VERY little more time to do so once the skill is developed. Payback comes from being able to deal with tight tolerance work with ease, to say nothing of being able to handle parts for second or third operations without concern. In today's society, where the bottom line is all important, that philosophy is no longer valued, however. The last job I held, I was told by one of the owners that he'd rather see me crash through a job, quality be damned, so that if they couldn't sell the parts, there'd be enough time left to make them again. I do not share that philosophy, and would be ashamed to have anyone think I did.
For myself it's an interesting (but frustrating at times) side hobby like Ron mentions. Trying for that unobtainable perfection sure doesn't do the ego any good either.
Probably not, especially in the learning curve, but that's exactly what I went through in my training. I got so demoralized that I couldn't do anything right, but, slowly, ever so slowly, things got better. They will for you, too, although keep in mind, I did this 8 hours daily, 40 hours/week.
But continual practicing for when it might or will be needed certainly isn't wasted effort imo. If your always used to .001"- .005" being good enough then trying to machine a light press fit bearing bore to a few 10ths is going to be real tough. A good guess about what depth of cut your machine should take after all that practicing sure helps.
I've tried to install that in those who read my ravings. Some get the idea that they'll never be called upon to do any close work, yet fitting a bearing is quite demanding. A snug slip fit is just as demanding of skill as a press fit, and you don't achieve that level of proficiency unless you practice. You can't learn these things by reading a book---they have to come from your hands and mind. Just like playing a musical instrument. Practice, practice, practice. And eventually things make sense.