flat to .0004 in

I can do that

____________________________________________

What's the tolerance?

The component is approx, 9: x 9"

Oh, just tell me whatchur working on. I'm intrigued!

Nicely done, Sir. Nicely done. Four tenths is one hell of a spec to meet. Love looking at your work. :toast:

I do CAD for satellite/spacecraft solar panels. Nursing a sore left arm this weekend. Hurts like hell. I'm having problems picking stuff up. And I have en engine swap and a head gasket replacement to do.

it is 4 ten thousandths.

4 tenths looks like this .4

.0004 is as it appears.

four tenth of a thousanth of an inch.

here is waht it lokoks like in math notation:

.0004

I'll try to explain it for you.
.0004 is a small mumber.

I was able to proiduce a component that was flat to half the tolerance.

The young engineer wanted .0004, I gave him .0002

..it is understood that I mean the fourth digit IE .0004, as I read in your first post. Four ten thousanths. I can do microns, but not on the weekend. ;-)

I know about .0004 flatness across 9", and I am suitably impressed, Sir. Nicely done, indeed.

EDIT: hard to spell on white russians

what is this?

Must suck to be you.

standards are in place for a reason, and that is to avoid exactly this type of confusion.

If your client came to you and said he wanted this piece done to a tolerance of 4 tenths, and you completed it with a tolerance of .4 when what he wanted was .0004 cause he thought it was understood that he meant .0004 when he said 4 tenths, you have a problem.

Do you see my point?


edit: and what's with the personal attack?

It seems like you missed that part.

:cry:

either about calling it 4 tenths...

They would say 'point four inches'. Tenths of a inch is not a common measurement. Thousandths, ten-thousandths, and fractions are common.

In this case, instead of 'point four inches', the person would probably simply say 'three-eights of an inch', which is .375".

0.4" is pretty loose, though. More for general carpentry than precision machining.

I did my best to define the spec.

.0004 in is about as specific as I could be.

:pals:

Not a machinist, but you pick up a few things here and there. Had to learn my fraction-to-decimal conversions when forming sheetmetal. We held about ± .031 for most dimensions, but sometimes we had to hold it to a sixty-fourth of an inch.

At my new job my boss is a machinist, so we talk about the tooling and such the owner makes for the hydroformer.

It's an impressive chunk of steel. About an 800 pound block each for the top and bottom of the tool set, then it's milled to within a couple of thousanths, heat-treated and nitrated, and polished by hand. It's about a three-week process if he hurries.

One time the top half of the tool set broke while heat-treating. Broke off like snapping a Hershey bar.

Twice.

Six weeks of machine time and five thousand dollars worth of steel... scrap.

Tried a new heat-treater on the third try, so now we finally had a new matched set!

you were not the person I responded to...

but, I was responding to a specific point in a post.

We generally work to +/- .005 on panel jobs and most panel handling tooling. Refering to ten thousanths as tenths among the enineers is not unusual, at this job or others. It is shorthand for when we need to engineer for tight tolerances, somethin we avoid due to cost, but made necessary depending on application of course.

When dealing with customers however, we use the drawings. Drawings are helpful. We use ICDs, which are also helpful. When dealing with customers, we understand what the tolerances are. We have experience in determining what the job needs, and we are often called upon to make reccomendations. Basically, we know what we are doing. That's one reason why our space flight solar cells are the most efficient in the world, and why our search spot lights are used all over the world.

Obviously, the issue was cleared up up-thread with a single post. Ptah and I will now proceed to engineer a suitable cage for your concerns.

when I need something engineered, I will not be talking to either of you.

it doesn't matter how you spin it, 4 tenths is .4 and 4 ten thousandths is .0004

Thank you for not planning to involve me in any of your future snits! :rofl:

this is 6th grade math. You should retake it.

Get down with your bad self! :rofl:

that doesnt know the difference between .4 and .0004

A tolerance of .4 inches is unthinkalbe.

so I don't go there to get machine work done.

edit: and you guys wonder why everyone else looks at you guys (engineers) funny...

Let me know where you can find a machine shop that works to .4 inches tolerances.

I don't think you can find one.

where I can find an engineer that knows the difference between .4 and .0004

edit: I do think that is an incredible tolerance to be machining anything to, that is impressive.

:rofl:

but making a bigger fool out of yourself. I asked every math major I know just to verify what I already knew. .0004 is infact 4 ten thousandths, not 4 tenths.


SO go ahead and keep laughing and do the rest of us here at DU a favor and let us know where you work so none of us make the error of going to your machine shop.

This is not geometry class, this is shop talk. In shop talk, when talking machining tolerances, a 'tenth' is short for ten-thousanth of an inch, or 0.0001".

This situation came up in American Chopper. Junior told Mikey he needed something twenty thousanths bigger. Junior meant .020", Mikey thought he meant a twenty-thousanth bigger, ¹/_20,000, which is 0.00005".

It's lingo, jargon, slang. Machine-shop terminology. Proof is that all the people who are machine shop rats understood it, and those in other professions didn't.

For example, when is a gun not a gun?
Technically, this is a gun:


This is NOT a gun, it's a howitzer:


This, also, is NOT a gun, it's a rifle:



In the general course of conversation, nobody is going to criticize you for calling an M16 a gun. But if you are in the armaments business, you will be criticized for calling an M16 a 'gun'.

Rather than criticizing, we are trying to correct and educate.

4 times .0001

.0004

I didn't mean to confuse you.

When I said .0004 in the OP, I should have
said .0004

Sorry to confuse you.

I think you are confused as well.

edit: I should have said that .0004 was LESS than .4

:cry:

I said, "n/t", why are you reading this?

We aren't sure what we can do until we try it.

Do you produce product?

Hydroformed and machined faucet housings and the machined spouts that attach to them. Several thousand per week combined.





We make our own tooling, and the boss holds that to a couple of thou or less.

..but I'm grateful!

on flatness.

:jawdrop:

my accepted tolerances...

now that you got it flat to .0004, i expect it perpendicular within four tenths too, and hold the size to the same. then pop a hole in the center 1 inch diameter +0 -.0002. hold the location to .0002 true position at least material condition. oh, and i need 36 of them. yesterday.

oh, and don't forget, it has to be U.S. sourced material too!





just another machinist/toolmaker/blacksmith, whatever, saying hi!



:hi:

about 170 deg K.

Part of the process is uphill quenching:

liquid nitrogen / boiling water

liquid nitrogen / boiling water

liquid nitrogen / boiling water

liquid nitrogen / boiling water

liquid nitrogen / boiling water

liquid nitrogen / boiling water

cycle five times,
then finish machine to size.

I love my job!!

with the cellophane from a pack of cigarettes...is .0004 that thin? cause i don't know. or like thin as a hair?

edit = thought i had a pic of the lakester x(

I just wanted to proclaim that I had produced something
that varied less than half the engineer's tolerance.


Score one for the shoprat!!

do the running man/cabbage patch, though consider carefully spiking your micrometer onto the shop floor :hi:

Cellophane, mylar and similar sheet materials are usually in the thousanths of an inch, or "mils" (more slang for this thread! Hee hee!). We plot color shop aids on 4 mil ink jet mylar (0.004"). We use 3 mil stuff in a different plotter.

That is a very tight point gap. Typical point gaps in more conventional engines is .017-.020.

Then there are old machinists who refer to 0.0005" as "half a mil". There is more slang, I've just forgotten it. Sometimes you gotta say "wait, point zero zero zero zero five?" to make sure.

Even worse, what if over time drawings for similar parts have been drawn in different measurement environments? Inches, millimeters and microns, and you have to seal with the old drawins at least until someone revs the design. That's some fun when you have to communicate with an outside vendor. But once a go-forward set of standards is established you can bring some order to these sorts of situations, but I tell you it's more common for standards to be lax than tight from what I have experienced over the years.

:hi: you doubtless heard that reason some time back; for NASA (i think it was) missing their target cause they out-sourced a segment of the project to a group that used the metric system sheesh who was watching that ball x(

The trajectory data from JPL was in metric, the thruster data by a contractor was in inches. Hilarity ensued.

"Investigators said Lockheed Martin Astronautics in Colorado submitted acceleration data in English units of pounds of force instead of the metric unit called newtons. At NASA's Jet Propulsion Laboratory in California, the measurements were entered into a computer that assumed they were metric measurements. "To be very blunt about it, it was overlooked. The specification was there and it was our responsibility to check that and to assure that the right units were made. It was overlooked by the engineers coding that software," said Noel Hinners, vice president of flight systems for Lockheed Martin Astronautics. "
http://techcenter.davidson.k12.nc.us/Group3/marsorbiter.htm

I deal with solar panel substrates for spacecraft supplied by European customers by taking the dimensions on their ICD (Interface Control Drawing) and converting to inches. I use inches as the main system and metric as an alternate (just turn on alt dims in Autocad). That way both the manufacturing floor and the customer know what is going on. But, of course, if I screw up it is revealed on the floor and we can correct it on the spot. I'd hate to be compiling thruster data.

but yeah i'd hate to have some astronauts whizzing
past some migrational error of mine as well, "Whoopsy!"
:headbang:

Plug gap on a Honda is .004.

I even called the factory technical support number about this. Four thousandths.

They don't know why either.

:loveya:

and would be the envy of any millstone dresser



The first type of tools used by the millstone dresser are the Marking Tools, the Proof Staff and the Paint Staff. Most proof staffs were made by John T. Noye of Buffalo, New York. Printed on the sides with raised letters was: JOHN T. NOYE, BUFFALO. They were made in 3 1/2, 4, 4 1/2, and 5 foot lengths for different diameter millstones. They came in a hardwood case and are covered with a light coating of oil. A wooden paint staff of the same length is made of a solid piece of maple or of 2 or 4 lengths glued together, with the grains of the wood running in opposite directions. The proof staff is used only as a gauge to check the level surface of the paint staff. The paint staff is rubbed back and forth over the proof staff. High spots are identified by a light coating of oil and scraped down with a piece of glass or steel scraper. The process is repeated until the entire surface picks up the oil evenly, then the surface is wiped off. Afterwards, the level surface is coated with a mixture of water and red iron oxide. Today, powdered carpenter's chalk is used to mark the high spots on the millstone surface. The high spots can then be taken down to create a flat surface.

Mad skills, my friend. Mad skills.

"If a sheet of glass with the same diameter as the Earth was flattened to .0004, the biggest "mountain" would be ___ inches/feet."

And no I don't want to do the math. You're the expert here:)

I think.

:hi: