While reading one of the Lindsay reprint books about machining techniques of 1894, I was struck by the amount of coverage given to bench or vise work techniques. Complete Practical Machinist by Rose ISBN 1-55918-246-6
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to be out of print at lindsay's)
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I know that hand-scraping is still used on some of the most precision machines, but what about "chipping" or chiseling? Is this still used in any shops, or has the cheap end-mill eliminated this entirely? How about "blind" oil groves in babbitt bearings?
Any of the cnc shops putting the finishing touches to a replacement part for a customer's obsolete machine with a cape chisel?
Filing seems to be stressed in some of the European apprentice machinest programs. Is "chipping" also covered?
Unka' George [George McDuffee]
------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
I had to use a chisel during my European apprenticeship. The idea of the chisel actually illustrates the basic cutting tool really well. Force vectors, cutting forces, edge strength, etc.
I've found that I'm ultimately happy to have some experience with a chisel. When you really need a chisel, most other techniques are fairly impractical. Mind you, this applies to fairly specific work (troubleshooting mostly), so I'm not sure a production shop machinist would be very interested.
We only had to chisel out segments of thin plate (too small to use a drill/hacksaw combo). As I understand it, the millwright Meister exam requires the production of a shaft keyway using only a chisel!
I've mentioned it before, but you can use scraping techniques with a well dressed die grinder stone instead of a chisel for flattening a block. Useful when the block has but one planar surface. I'd say this is an "old" technique.
Speaking of the "old" way, I can't say I've ever used my experience in riveting for any serious application. About the only thing that work taught me was to not use rivets! What a pain.
I suppose it's a good education in the importance of balance and attention to detail in press work. If you start a rivet incorrectly, you're making life *very* tough/impossible later on in the process. Interesting education in cold-forming.
A lot of the skills went away when various processes vanished. Why learn to cut a keyway with a cape chisel in the middle of a 50 foot shaft when they took all the overhead shafts out of the plant and replaced them with individual motors.
Do they use babbeted bearings any more? Do people still pour them?
I did once get many brownie points by being able to re-scrape a 4 inch bronze bearing on an old surface grinder but most of the old skills just aren't needed any more.
Hard to find a wheelwright to tighten up your buggy wheels or a good buggy whip maker these days and for quite a while a farrier was damned near impossible to locate - although I hear that trade is making a modest comeback. Looks like gunsmithing is also a dying trade too.
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)
My take on these hand techniques is that the purpose of a modern cnc shop is to eliminate hand work as much as possible in the interests of speed, accuracy and pruduction volumes.. However in the wood working trades and stone masons work chiseling is still an important skill. Now for other metalworking skills like in silver or gold smithing hand techniques are still taught including chiseling. For example removing flases from small castings , its much quicker to chisel them off than setting them up in a mill As many flashes are of different sizes.. also filing is used extensively in the jewellery trade. Also a modern cnc shop would most probably decline the repair/ remaking of an obsolete part for an old machine as they wouldnt have the old tools left any more. In several cnc shops I put work to they dont have a general center lathe anymore. Iknow of a few general machine shops that can turn their hand to almost anything , but there few and far between now. Generally a one man type shop who can turn his hand to almost any one off job. Youll find threm in rural areas repairing farm machinery and the like.
Useful for repairs, kludges, and one-off's, however.
I don't rivet much, but I was able to apply the techniques learned from hanging out with a darned good plate armor armorer who rivets a lot (it's historically correct) to repair my backhoe by replacing a swing-chain pin with an appropriate sized hunk of grade-8 bolt, and peening it in place with a small ball peen hammer, a moderate anvil, and
45 minutes of tap, tap, tap.
Given than it's $300 just to get the thing hauled off for someone else to even start looking at it, much less the cost of them fixing it with replacement parts as opposed to rebuilding parts, it's a worthwhile skill to lurk in the skillset, when needed.
Likewise, it's clear that sometimes the ability to cut a keyway with a chisel would get the (one-off, repair or modification) job done faster and with less specialized and costly tools. Have to give it a try when I've got some spare time.
Most whip makers are now chinese and they cater largely to the Western S&M trade, though there are still quite a number of US craftspeople still making them for both legit and S&M trade
Farriers are indeed making a comeback, as there are more horses in the US today, than at any time in its history.
Course most are riding stock, not working stock...not many plow horses or milk wagons...
Gunsmithing is indeed a dying art. They have two issues..governmental regulation that is worthless but a huge hinderance and have added huge costs, and gunsmiths have largely priced themselves out of the market for many people.
Thats the reason I first learned machining, because I wanted custom stuff, or to repair stuff, but couldnt afford the prices most smiths were charging even then. I do nearly all my own gunsmithing, and let/teach friends who come over to my home shop to do repairs/mods of their own.
No, chipping means chiseling metal out of or off of a solid piece. That distinguishes it from cutting, which, with a chisel, refers to chiseling a shape out of sheet or plate, either punching it out or shearing it off.
As I've said before, a lot of people interested in metalworking, but who don't want to or can't buy machine tools, can get a lot of pleasure out of learning to cut metal with chisels and files. I had the good fortune to learn chipping from an expert, and I still have his cape chisels, goosenecks, and the whole works. That's how I got started in the hobby. You can do a lot with chisels and files (and a hacksaw) if your object is to do metalwork, rather than to produce *things*. At Rogers Locomotive in NJ, they made entire locomotives without a single milling machine, using chisels and files.
As a service tech, its damned surprising how few shops have even a bench vise, drill press or much in the way of hand tools. Few have a manual mill or lathe either.
Been a number of times Ive had to clamp something in a CNC mill vise and cut it off with a hacksaw...which is an extremely odd concept if you think about it.....
The other day I watched a History or Discovery channel show on the bronze age. They showed a very nice bronze sword and the Phd expert was going on about how we couldn't make one today. With what bronze casting I've done I'm pretty sure I could make one with similar molds to the original with a week or two of practice. With modern technology I'd spend more time waiting for the UPS material delivery than making the sword. Experts really need to talk to people who actually can use their hands. Karl
Rogers dates back to the 1830s. There are plenty of photos of their later production, up to around 1910, but there isn't much on the early days except the archaeological digs of their first plant. They unearthed piles of shop-made files in that dig.
I did a brief interview of an "industrial archaeologist" who was involved in unearthing Rogers' history, which was published in the 100th Anniversary Issue of _American Machinist_ (I think it was Nov. 1977).
It is not a locomotive but when I was an apprentice boy we built wood working machinery without a milling machine. In fact mills weren't used that much as either planers or shapers could produce a flat surface quicker and we didn;t make that many gears.
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)
Pouring babbitt isn't all that hard. You just need to follow a few rules. I pour babbitt, hand scrape bearings, hand file journal caps and quite a bit of the old techniques do a better job, IF DONE CORRECTLY, than any machine out there. Plus there are more than a few times that using high tech equipment wouldn't work because of the location of the part. Or to keep the item accurate. I even ran across a weird engine a few years ago. It had two tapered throws on the crank and I was ready to have them ground true when I discovered that the castings for the bearings areas were cast with a taper. Turned out that the designer had decided that the taper held the crankshaft in position better than a thrust bearing.
======== Anyone that has an interest in Babbitt bearings should take a look at
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I have all three books and they are a good read, even if you never rebabbitt a bearing. Gingery's (book #3 above) is current.
Makes me glad that I can buy off the shelf ball/roller and sintered bronze bearings in about any size I need.
However from what I have seen in the machine shops in the smaller communities, many of the local manufacturing plants continue to use old equipment, frequently with babbitt bearings. While new equipment *MAY* be available, it will be imported, and the price is such that the operation would no longer be economically viable with new expensive machinery.
While replacement parts may be produced on cnc equipment, these are frequently "reverse engineered" from existing worn-out parts. In many cases, the U.S. companies that produced the equipment years ago are no longer in business, so these machine shops are keeping a number of small-town manufacturing operations (and thus the town) going.
From what I could see, the "reverse engineered" parts tended to be "blockier" in that a "machined from the solid" or weldment was replacing a casting. Also a fair amount of flame spray/welding and remachining. I did not notice any "chipping" to complete the part, but some die grinder work.
Unka' George [George McDuffee]
------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
========== Does this seem to be more of a problem in shops run by accountant types rather that traditional "hands on" people?
Seems to be very similar to the person who gets a brand new car and has no tools of any kind, not even a jack and lug wrench. The slightest problem brings everything to a stop and is very expensive to correct. (Keep the cell phone and credit card handy...)
Unka' George [George McDuffee]
------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
I'd like to see that one. My uncle had some great stories about jury-built equipment they made in the Seabees, in the Aleutian Islands during WWII. Of course they had good equipment to start with, but they had to build a lot of things from scratch.
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