It certainly could be. But..in machining..its got a very specific meaning. .0001"
__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
.0005?
5 tenths in other words. And those are common as dirt.__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
ayup.
Gunner
__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
How many people reading this have ever done any sort of work close to that precision?
This is what you claimed. "We work to tenths of thou"
jim fired this volley in news:FpGdnZc- W8rjwA_PnZ2dnUVZ snipped-for-privacy@bright.net:
With a short, stiff cutter and slow feeds, I can work to half a tenth all day. Certainly, that's not 10 micro-inches, but I can buy $7.00 bearings from McMaster that meet that spec.
I can't, because of the age and condition of my machines. But my CAD and CAM work to those tolerances and below.
Somebody said in this thread that some CAD worked to an internal precision of 0.0001"... hell... my cheapest CAM software works to seven digits!
Ten micro-inches is not an amazing feat with new (but fairly specialized) equipment.
Lloyd
I can work to a tenth with floppy piece of sandpaper, but that is a little different than creating a CAD model and then manufacturing the part to within a tenth of the model dimensions.
And how many of the 'we who work to a tenth' could make that bearing?
So can Sketchup. It uses floating point data which means it can describe geometry about 1 million times more precise than anything you could make.
One would hope so for most calculations. However it is kind of pointless to pump out G-code that is lot more precise than the machine tool positioning capability.
People have been making things flat or round to that level of precision for ages.
jim fired this volley in news:H8WdnTONgeg28Q_PnZ2dnUVZ snipped-for-privacy@bright.net:
Yup... I can make a piece of glass flat to about three angstroms by hand.
But your comments to the negative don't bear on the discussion. The discussion never was "how many of 'us' could do it"; But is it a realizable and realistic degree of precision?
Yes, it is... even with the sort of equipment I use (albeit newer and in better condition).
I'm not working with a table-top Tormach, and do this professionally. But even a lot of amateurs have older high-end industrial equipment. It sells for scrap value, if one is willing to do the work to rescue it and upgrade the electronics.
I just had an 'amateur/recreational' machinist friend buy a full-up Fanuc slant-bed turning center with 4th axis, 12' bar feeder, and live tooling (+ATC)... With a little TLC and good insert tooling, that machine will do sub-tenths work -- in his garage!
Lloyd
Lloyd
__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
Guided missiles and rockets are two different things. Nuclear missiles are "ballistic" (even they are steerable), rockets, not so much. You can't orbit an object in a ballistic trajectory. They
*have* be able to correct their trajectory. Not only does/did the Shuttle have aerodynamic surfaces and steerable main engines for atmospheric corrections, it has/had OMS engines and thrusters fore, and aft, for extra atmospheric corrections.
Flat and round (spherical) are trivial problems and as you note it's been done for ages, at least since the middle ages. Other shapes are more difficult, as is size.
Ayup...lots of guys have retired from companies that were closing down due to the Obama Great Depression Part 2..and have bought for pennies the very machines they were running. Doing some small machining in their garages..usually medical parts (big money). We have seen Cottage Industry come back in a big way across the US. Its not talked about very much...shrug..but its quite fascinating how many "pro shops' are in your neighbors garages.
Gunner
__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
Blink blink? Say what?
Half a tenth is 50 millionths.
__ "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Heinlein
And there isn't much advantage in having a CAD model for those shapes.
And it is doubtful there is anyone reading this who is cutting complex shapes from CAD models with precision held to tenths.
There isn't much reason to have a CAD model for a board, either, but when you want to put a few dozen of them together, having a CAD model gets rather interesting.
Huh??? Have you ever heard of a mirror, or lens, system? Please explain your statement?
Me, for laser optics in the space program. They invited me in as the electronic tech, then I got the mechanical design and fab part of the job by demonstrating that I could center a gage pin to +/- one micron in a 4-jaw lathe chuck. jsw
OTOH, I had the greatest admiration for Admiral Hopper, and she certainly liked it :-).
With care and patience the half-century-old machines in my home shop can still hold around 2-3 tenths. jsw
How many have you modeled in CAD and then manufactured to within tenth of the designed part?
You must not have any personal experience (I do) in R&D in the semiconductor industry.
Nope never had anything to do with the semiconducter industry.
I thought we were talking about cutting metal.
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