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chief
02-13-2003, 05:46 PM
My intention is not to belittle anyone and I have had as many problems and question as the next guy but after twenty some years of turning metal (usually under some unrealistic deadline). I have noticed that a good many things in the machinist world I
just don't pay attention to.speeds and feeds,
if the bit isn't glowing red or the aluminum isn't melting it's ok.
toolbits,carbide for hard steel,HSS for soft,
easy enough. I look at a piece of stock and know if it's going to work, no need for elaborate metal tests.
I read the articles sometime and think,"boy I should do that or waht a waste of time".
I guess my point is be safe and enjoy the hobby and don't get wrapped around the axle on the little stuff. It kind of reminds of the old joke:
The young recruit says" they taught us to do it like this in bootcamp"
The young, junior officer "in my experience"
And the old, wise sargent says" watch this ****".

WJHartson
02-13-2003, 06:39 PM
You do pay attention it's called experience and we keep adding to it each day.

Rotate
02-13-2003, 06:41 PM
My guess is that all your experience have thought you get a "feeling" or "intution" about things like speed and feedrate. I guess it's like anything else. I have never seen my mother cook with a measuring cup, thermometer, or scale. She did everything by feel and taste. When I married, my wife owned more graduate cups, flasks, beakers, and scales than a well stocked chemistry lab.

You have earned your badges and there's nothing wrong with what you're doing. Of course, if you're doing high volume production then optimizing the variables can be the difference between breaking even and profit.

Albert

John Stevenson
02-13-2003, 06:53 PM
Too true Chief.
I taught my lad all I know and he still knows nothing.

Employ a teenager whilst they still know it all.

John S.

SGW
02-13-2003, 09:10 PM
Re: cooking by feel and taste. Reminds me of the clam pie recipie card my wife inherited from her grandmother. In its entirely:

Clam Pie
Clams
Sauce
Piecrust
Cook until done

Thrud
02-14-2003, 12:09 AM
chief:
I only worry about specific materials if it is really important - like when I make tips for my Hakko desoldering station, restoration of a historical piece, or a special job. Otherwise I don't sweat it (LYING BASTARD!) too much. http://bbs.homeshopmachinist.net//biggrin.gif

I have come to a point in my life where it does not matter as much to me, and that in itself disturbs me. http://bbs.homeshopmachinist.net//frown.gif

docsteve66
02-14-2003, 11:56 AM
Dave: your "I have come to a point in my life where it does not matter as much to me, and that in itself disturbs me" is very insightful!!!!! I had said much thesamething to my self a few days ago- but it was not so consise as your saying.

I was thinking to my self- as I cobbled something together- few years back I would have done this differnet-hell few years back I made things to last until the job was done forever or at least til i died. With age I seem to have dropped the forever criterium. And I said to my self (as as i looked at the cobbled up mess) "Self, you seem to think you are on deaths door step" http://bbs.homeshopmachinist.net//smile.gif

Guero
02-14-2003, 08:10 PM
Doc, Thrud: I saw that with my dad, who lived to the age of 82. He was pretty much a perfectionist and while his profession was actually that of an aircraft engineer, he also had his A & P license and was a genius at working in metal, be it welding, sheet metal work, machining, etc. When he was still in his 50's he enlisted my help (I was not yet a teen) in building a small shed in which to store my brother's MG while my brother was in Vietnam - this shed, though built literally of lumber scrounged from abandoned houses (this was rural North Carolina in the late 60's) is still standing today and will probably still be standing 20 years from now. I helped him again when he was in his 70's, he wanted a shed to store his RV in and that shed will need to be torn down soon as it is already starting to fall apart. In other things as well he seemed to "make for today" and as long as it served his immediate needs, he was satisfied... and yet I inherited some of the specialty tools which he made while in his 30' and 40's and they're pieces of art - not just functional but beautiful to look at. Even very simple things, like a small gear puller, were polished and case-hardened... he built them to last beyond his lifetime.

Thrud
02-15-2003, 01:03 AM
Steve
If I have learned anything in my many brushes with death is as long as the world is giving you sh*t and abuse - you are still alive! Worry about it when you start to feel really, really, "special". http://bbs.homeshopmachinist.net//biggrin.gif

darryl
02-16-2003, 07:39 AM
I'm wondering about cutting speed, does it change depending on what you had for dinner?

Thrud
02-16-2003, 07:45 AM
darryl:
Sure! Sometimes you feel so good after a great meal you are full of piss and vinegar and everything just clicks. Other times, you turn the feed down and go whack your thumb with a hammer on the bench - accidently, twice. http://bbs.homeshopmachinist.net//eek.gif

lynnl
02-16-2003, 10:17 AM
John S., those were funny! I'm imagining some good impressionist doing that first line in Dubba Ya's voice. http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif (George DubbaYa's that is. or maybe Al Gore's)

Thrud, your last post brings back a painful memory. I did that very thing. Whacked it so hard I cried. Let project rest for 2 or 3 weeks, then resumed EXACTLY where I left off. (Same hammer, same nail in same hole of same board ... also same thumb!) That time I didn't cry, I wove a tapestry of expletives that's probably still hanging in the air today.

[This message has been edited by lynnl (edited 02-16-2003).]

docsteve66
02-16-2003, 02:41 PM
Lynn : http://bbs.homeshopmachinist.net//smile.gif RE: " I wove a tapestry of expletives ......"> I sure hope that phrase is not copywrited ot protected in some way. I intend to use it one day!!!
Steve
Problem is my cussing buddies dont know tapestry from tape, expletives from explainations and the people who do know are ones that I say, "I really should have thought more before trying to do that".

lynnl
02-16-2003, 05:54 PM
Steve, I gotta confess, I sto.. 'er borrowed that expression from the movie "A Christmas Story". It was about a little boy growing up in Gary Ind. who wanted a BB gun for Christmas. It's narrated by the boy recalling that period later as an adult. He said of his father: "...profanity was his true medium. ... he worked in profanity like other artists might work in oils or clay..."
One of the best movies for the holiday season, especially for guys, tho my wife and daughters like it too.

Spin Doctor
02-16-2003, 08:40 PM
But Lynnl' YOu'll shoot youe Eye out!

Thrud
02-17-2003, 02:13 AM
lynnl:
And after a while you get used to the taste of bars of soap - that really got my mom pissed off - she didn't know what to do then, she was so flustered and my dad was laughing...

Funny show. A true classic.

Jaymo
02-19-2003, 11:11 PM
Thrud--when I got to that stage, my mom would just peel an onion and stick it in my mouth. She knew that I coudn't stand onions. It was much worse than soap. At least she could have cut them into rings and fried them first. A little ketchup wouldn't have hurt, either.

Thrud
02-21-2003, 12:20 AM
Jaymo:
At least it(soap) tastes better than spinach - I hate Spinach. http://bbs.homeshopmachinist.net//eek.gif

darryl
02-21-2003, 02:40 AM
Spinach, mmm. ok Know what's tastier than spinach? Stinging nettles. Pick them properly, and you don't need gloves. Use gloves, pick a peck, boil 'em up and yummm. I hate soap.
Tapestry of expletives, I like that. I imagine we've all woven one of those at one time or another.

lynnl
02-21-2003, 01:47 PM
Another of my favorite expressions is a 'recto-cranial inversion'. (see also "Political Leaders")

docsteve66
02-22-2003, 08:39 PM
then there is "singuluar rectal opticalitus"- a condition suffered by those who have ONLY 20/20 hindsight

docsteve66
02-22-2003, 11:07 PM
I mentioned that i no longer made things to last forever- maybe its a case of better judgement today.
The Motorhome shed (10 years old) will not last another 10 years, but i just put a new alternator on tractor (tractor is probaly 50 years old (A massey Ferguson TO 30) but it will last another 50- at least more than I will last. It will go to son in law and hopefully Gson. The modified bracket and alternator will last till the tires rot off or the wheels rust out. 20 years ago, the welds would have been ground, edges smoooth and would not have lasted ten minutes longer as the result ofthe extra work work. maybe foolish pride has flown at last!!!!
Steve

Endmill
02-27-2003, 04:16 AM
I agree that there is too much focus on feed rates and cutter speed, clearance and rake angles and on the merits of carbide vs HHS vs ceramic etc.

These parameters may be of economic importance in fine tuning an automated camshaft factory where the expertise is presumably built into the system, and the selling price is based on projected return on capital investment.

Some of the hype may also be attemts to market marginal product improvements or oversell expertise. Accuracy and precision are also hyped to habit forming excess. I don't need 0.001 tolerance for bolt holes!

Items are sold by the piece, but labor is purchased by the hour and profits are highest where wages are lowest. (The correlary is that given sufficiently low wages anyone can make a profit.) (The Chinese are still making a profit, but the Japanese are not.)

The pressure is obviously on time, but since each job is likely to be different, a set of general default values will likely be more cost effective than exhaustive analysis, or continually resetting machine parameters. This is what an experienced hand does automatically.

The problem is that someone improperly bids a job, and then trys to put a time monkey on the machinist. After six meetings they decide that the cost overrun was due to too slow a feed rate.

Most of my life has been spent doing and managing R&D. An expert is someone who has made all possible mistakes but learned from them. Correlary: The height of stupidity is to keep repeating the same thing and expecting a different outcome.

Procedure or technique or work break down is of more significance than setting parameters, and anything that works well is correct.

I generally build something in my mind before I ever start work. I break the task down into steps, and mentally complete each one, and then write myself a short letter describing each of the steps as I visualized them with the projected outcome, and any possible problems. (For something new, I may make a baseline model, and do modeling to convince myself that what is proposed will work.) You may identify steps which you don't have much experience with, such as using a special tool, in which case you should validate your methods on some scrap.
Sketches and dimensions come next, along with materials, needed tools and fixtures. Parameters are added last. (Your outline could include a list of critical dimensions and a place for your final measurements.)

Even if one starts with a set of prints, you still need to match these up with your specific tools, available materials and specific tasks, and making a plan or outline is worthwhile. You then know what sizes of drills, counter-bores, taps, lathe tools etc are need, along with other supplies. Also you can check for consistency in dimensions, drafting errors, and omissions, and if necessary, make some phone calls to clear up the unclear.

On large work (which I don't do), you will know when you need some extra help or lifting equipment. There is no excuse for dropping a lathe chuck on the ways, or drilling into a table.

I try to estimate the needed time for each step before I start, and leave some space for actual times. You can then set up your work day, lunch or beer break, and stop work when you are overly tired or stressed out and more prone to errors.

The plan is basically for your benefit, as a self management tool, but it obviously has political uses if you are an employee. (A collection of these, with some finalized details which compare your projections to actuals is potentially very valuable to management in submitting bids for similar work or in proposal preparation.) Also take some pictures if you can of your setups and finished product(s) This is good for possible HSM articles, or future job hunting if your talents are unappreciated.

I am conservative in most tool settings.
Once in a while I change the speed of my drill press, but I haven't changed the milling machine from its mid-range setting in 10 years. Same thing with the metal band-saw which is on the slowest setting. I cut 8" sections of stainless without a problem as well as aluminum. What I loose in time I save in blades.
End of Rant
Bob