Results 61 to 80 of 92
03-20-2017, 08:28 PM #61
03-20-2017, 08:55 PM #62
Pete F liked this post
03-20-2017, 09:16 PM #63
Here you have a guy who asks what is admittedly a stupid question. But at least he is asking it, so he can learn, just like you did. There's plenty who don't know jack, but they sure know it loudly.....
Instead of jumping his case, you can spend the same amount of time giving him good info instead of what he is assuming. Then at least ONE engineer would know some real-world stuff.......
03-20-2017, 09:42 PM #64
03-20-2017, 09:56 PM #65
Having backed into the profession, starting without benefit of advanced schooling, I started by making things others told me to make, graduated to making things I thought up and eventually to having other people make things I wanted. One of the greatest frustrations, especially dealing with engineers above my status and pay grade, was "designers" who hadn't the slightest notion about how things were made. Eventually I achieved status and pay parity, so I didn't have to take orders from them but still had to deal with them.
Now someone comes along wanting to learn about basic processes and most of you waste your efforts sniping at his semantics. So he could buy a better gauge block than he can make. Why would one of the best engineers I know make a violin, including the special tools to cut the purfling groove, etc. when he could certainly afford to buy a better one? Maybe because he wanted to. What other justification does he need?
pcm81, Simply ignore Pete F's posts. I try to avoid reading them but when I do, my dominant emotion is gratitude to whatever deity pulls the strings in our universe that I don't have to live in his head.
03-20-2017, 10:13 PM #66
Somebody pointed out that I recently asked about how to increase my insert life when working 4140 HT, as I wasn't getting the correct life from the inserts on my particular noodle. Before asking that question I hit the search function and quite spent some time getting off my ass and trying to learn for myself instead of just just sitting back and waiting for somebody to spoon fed me. It was only after I'd exhausted the search possibilities and tried many thing myself that I hit the post button and reached out for help.
Believe it or not I'm generally not a grumpy person, but I have zero tolerance for laziness. Bludgers who want to sit back on their lazy ass and expect somebody else to do the work for them, while they spew out excuses why I should feel sorry for them.
Nobody is having a go at anyone for trying to learn. What many here, and not just myself, are saying is to think for yourself before posting and wasting people's time. Particularly when I would place a reasonable large bet that no "gauge block", or anything else, will actually emerge from this exercise, and it's nothing more than just wasting people's time. Tyre kickers we call them down here.
03-20-2017, 10:17 PM #67
03-20-2017, 10:26 PM #68
03-20-2017, 10:27 PM #69
03-20-2017, 10:44 PM #70
While my original question has already been answered by several kind and wise members of this forum, I feel compelled to also express my appreciation for the comical value this thread has generated as the result of members bashing and defending my intelligence and ignorance.
03-20-2017, 10:50 PM #71
Take a deep breath. pcm81 has something like 67 posts. Give him a break. Learning by working in a machine shop is, we can all agree, a superior thing to do. Take me, for example. From my earliest youth I wanted to be a physicist. I spent all my time as a kid taking apart old radios and tvs and trying to build things. I almost cut a finger off trying to machine a glass cylinder to make a Van de Graff generator. When I got to college, I majored in physics, and took all sorts of math, theory, and engineering classes. Thankfully, UCSB at that time had a mandatory shop class for all physics majors, in which you went to the student shop and a kindly and very knowledgeable machinist named Gerry Leaper tried to keep all your body parts attached while showing you how to use machine tools to build experimental tools.
My entire career has been hugely shaped by Gerry, and the other machinists who realized I had a deep desire to learn their craft, and respected them for being in it. They took me under their wing and taught me processes, techniques, and ways of thinking about things which were enormously helpful in not only getting through grad school, but in my career at IBM Research. There, instead of DOING physics myself, I found myself designing and building tools for DOING research. Some of this involved optics, lasers, electronics, and so on, but a lot of it was working with the model shop to do projects where runout of spindles in the microinch region was mandatory, where motions of 0.1 micron had to be controlled and held all the time, and so on. I could NEVER have had a CHANCE to succeed at this without the cultural understanding and skills i learned in the Physics department shop.
PCM81 is not trolling. It seems to me that although his job may not be doing fabrication work himself, he has realized that UNDERSTANDING it will help him communicate with those that do, will help him earn their trust and respect, and will be a win for not only himself, but also his company and the people he works with.
How often have I heard people on this site (and in all the shops I have ever been in!) bemoaning the ignorance and stupidity of engineers who know only theory. I have on multiple occasions had machinists beg me to get involved with a project where a "theoretical" engineer who had no idea of tolerances, materials, machining practices, and so on was asking for things that although marginally possible, were just plain STUPID!!! In many cases I was able to help inject a bit of real world into the process because I was seen as a peer by the engineer (and they like coffee and donuts), and because I could speak not only his language, but also the language of a CNC machine at full throttle. Everyone won. Me, because I got to do something useful and interesting, the engineer, because his drawings got built and WORKED, and the machinists, who stopped eating Maalox like candy.
So before we start pouring poop all over people who want to learn and are willing ask naive questions and to make chips and get dirty to do so just because some of use are better at machining than they are, take a deep breath and look at the big picture. Now is not the time in our country to be divisive. There is far too much of that going around all over. Lets try, instead, to be a little more kind, to think before we let our frustrations (and I sure have a lot myself)cause us to say unnecessary mean things on a forum. Maybe make a point by telling a story. I am sure all of us here have a bunch! Make some helpful suggestions, and if they are rejected, really- it is the rejector that loses. I learn a LOT listening advice being given to others. So even if a specific piece of advice is not acted upon by a specific person, many others are listening and it may be of value to them. What we say in a post may be read by hundreds or even thousands of people.
So now lets all go out and sing KumBaya and have a beer, ok???
All the best in these turbulent and unsettling times,
03-20-2017, 10:50 PM #72
Revising the Question
For the sake of REDUCED argument.. may we suppose that the real question might have been:
Does modern, computer ASSISTED machine-tool technology largely obviate the need for hand-scraping?
The best of modern machinery has pushed repeatably achievable tolerances down to the point where any BETTER accomplishments are limited by thermal expansion and contraction of the materials being worked.
We surpass even those when we need to mass-produce heads and platters for rotating memory "hard disk drives" on an astonishing scale, and further yet when we polish a semiconductor wafer to manufacture integrated circuits economically in greater numbers, yet. Clean rooms. Temperature control. Vibration isolation. No longer GOOD enough. Go and build better!
Not limited to the labs, either. "Lapping" to insanely precise levels goes on in muddy ditches the world around as tiny portable machines polish the ends of several optical fibres at each go to permit near-as-dammit "lossless" splicing for long underground conduit runs,
"Hand scraping" lives-on partly because a highly skilled craftsman can ship or even hand-carry all the tools and references he needs TO a machine-tool that would be far more costly to transport to where machines were available to correct even PART OF what the craftsman can correct on-site. Often, he can complete that correction before the machine could even be pulled from service, dis-assembled, and prepped for shipment.
Even then, it needs the assistance of his sort of craft to complete the fit-up once back on-site and being re-assembled.
Machining, grinding, lapping, and hand-scraping are not entirely and always mutually exclusive processes.
Quite often two if not all are used in concert, most especially where precision repair is at work.
For brand-new goods, ANY process that can be reduced or eliminated is 'in the plan'.
Ergo where volume and economics so justify, hand scraping or any other 'hand' work will be minimized, if not eliminated outright. That is done by use of the most appropriate machinery capable of utilizing processes than substitute their tirelessness and even inbuilt metrology for ANYTHING dependent on frail humans who are scarce resources - and who can get tired even more often and easily than fired.
When that is not good enough, we re-design the sumbich to not NEED whatever it was as was costing too much.
Solid-state memory hasn't yet replaced 'hard drives' for storage, but it - or its own several replacements - assuredly WILL do in the fullness of time.
Learning is the goal?
First find out how any given item IS CURRENTLY made, how it WAS PREVIOUSLY made, then see if there is still room to improve on that progression by enough to justify the cost OF said improvement.
Improving the surface finish of disposable Bic lighter bodies is probably not a winner.
Increasing the life of ZF, Getrag, Allison, or similar automatic transmission clutches by even five or ten 'assured' percent almost certainly would be a winner.
No shortage of technology. No shortage of challenges.
Drive on, soggy humans!
That 98% water you are dragging around is only on short-term loan.
Do SOMETHING useful with it while it is still your turn in the barrel.
03-20-2017, 11:18 PM #73
Nicely said, Monarchist!!
03-20-2017, 11:21 PM #74
03-20-2017, 11:57 PM #75
Does modern, computer ASSISTED machine-tool technology largely obviate the need for hand-scraping?
03-20-2017, 11:59 PM #76
I think the OP's original question is about the same as "what's more accurate: drilling a hole, milling a slot, or broaching a keyway?"
They are all as accurate as you make them but each have their own application. As technology has improved in each process, operations get re-thought and there will be parts that were once ground (for example) that are now milled to produce the required accuracy and surface finnish. Dosn't mean grinding is becoming obsolete. Scraping isn't as common as it once was but IMO it has nothing to do with accuracy and everything to do with economics.
Builders today have to build machines that move faster than scraped ways should move, and they need to hit a price point where linear ways are shimmed into place instead of scraping castings into tolerance. When you get into heavier cutting machines with higher tolerances on how everything fits together, you still see scraping.... because it's cheaper than building those same components on a massive high high accuracy mill or grinder.
Everyone wants the highest quality their dollar can buy. That means that machinists and machine tool builders alike need to hit the tolerance, high or low, as economically as possible, regardless of how dated or cutting-edge the process is.
03-21-2017, 12:25 AM #77
But weigh this, if you will:
"Eventually" we started getting traction and a bit of mileage out of the exercise he started, however clumsily.
We've found even hard-core 'manual machinists' and right fair 'scraper hands' in agreement as to some of the major changes in an industry we have varying degrees and flavours of interest in.
Took a while. Wasn't a quiet process.
Still came back on-point, finally - and way to Hell and gone more usefully than whether the US Prez is sane, rides side-saddle, or eats a brown-bag lunch.
I can deal with that advantage, and the tilt back to our 'craft' - warts and all.
We ain't EVER going to agree for long on ANY of the politico-socio bullshit, and should not even try, nor worry about that, lest we fail at sharing what we DO have in common.
Mangling matter to our whim, our will, or to those of a paying customer.
03-21-2017, 12:27 AM #78
03-21-2017, 12:37 AM #79
The OP has a problem.....
He does not DO the work, so it's harder to understand. Worse yet, apparently he is an engineer, but a project administrator and not a designer, so he's even farther from the shop. He's on track to be the clueless "pointy-haired boss" if he does not learn some things. For folks who DO make parts, it's not an issue,
Most folks here own or work in a commercial shop. Some of us are "part timers", like myself. (I spent a dozen years acting (in addition to my regular job) as the "captive model shop" for two different employers, using my own equipment. made jigs, fixtures, one off or small run prototype parts for show samples, new products, etc). Probably there are some pure home shop people. I know there are retired folks who worked in shops for decades and have a home shop now.
It's harder to see how a person could NOT know the stuff if you have made parts, used the equipment, and generally had at least some experience. Even a "home shop only" person knows more than someone who has never cranked the handles. But it's kinda hard to put yourself in that position and "get" what they don't know.
I don't know the posting history of the OP. And I don't care. I only answered because it seemed he was getting nothing but bashed for asking. It's kinda silly because it takes just as much effort to write a bash post as a helpful one.
Why even bother? If you want to see a post get buried, just don't answer it, and it will drop off the page just as if it were closed.
03-21-2017, 01:11 AM #80
Dunno for sure, but wart virus and cancers - or at least carcinogens - are somewhat linked, going by frequent progression triggered off HPV & such.
Only a few years ago they found something in Turmeric to kick prostate cancer right off the game-board.
Not sure where that research has gone since, verified or rejected, but I had lots of Turmeric to-hand, so.. R&D time.
And nooo it weren't near my former joy-stick/dip-stick, now coolant drain-hose, either!