Metric/imperial

Nope, 0.125 Gallons [US] = 1.043158 Pounds I think you are referring to an imperial gallon

0.125 Gallons [UK] = 1.2527805 Pounds

I was coming through customs from the Bahamas with a 40 oz. quart of rum. One quart ( US 32 oz.) was duty free. The customs guy wanted to charge me tax on the bottle. There were four of us traveling together so said " how about each of us drink a couple of oz. out of the bottle?" I caught him off guard with that question. He stood there for a couple of seconds thinking and then let us through with the bottle.

John

Mike wrote in news: snipped-for-privacy@4ax.com:

Seems the commerce dept. knows something the CIA doesn't

On Sat, 26 May 2007 19:56:42 -0400, with neither quill nor qualm, john quickly quoth:

You're lucky it wasn't Lemonhart 151 Demerara rum and he didn't take you up on it. ;)

LJ--ex-rummy.

- Metaphors Be With You -

The Modernized form of the metric system of units known as the International System (SI) adopted by the 15th General conference of Weights and Measures (CGPM) May-June 1975 and sanctioned by the International Standard Organization (ISO). This is also recommended by the Metric Committee of the American National Metric Council (ANMC-75-1). [ extracted from "The Nature and Properties of Engineering Materials Second Edition - SI VERSION" Jastrzebski (Author).

ISBN 0780310500 "Metric Units and Conversion Charts"... Theodore Wildi Nice paperback reference.

Martin

Mart> Correcti>

Hey Strap ! Clue me in. What is "Lemonhart 151 Demerara rum"?

Thanx,

I agree with the machine being a big factor in forcing the primary units

I use old american machines here in canada and i have ran into an issue many times where i need to cut metric threads or similar or i run into metric dimensioned parts.

I am in general measurement bilingual since there are sections of canadian industry where the metric measurements are NOT the actual observed standard even if the standards are all written in metric

i think the best thing to do will be to retire my current lathe for more rigid dual threading one rather than to constantly try modifying the gear train by adding a 127 tooth gear

I also think a DRO that will output in both units will make working in either instead of only one set much easier

[ ... ]

O.K. You may be a bit larger than the average person was when those units were formed. :-)

:-)

You don't use the threading dial? That may explain it -- but it suggests that you either have a CNC lathe, one with additional features to automate that, or don't cut many threads on the lathe.

On the imperial lathes, cutting imperial threads using an imperial leadscrew the threading dial is mounted on the carriage and meshing with the leadscrew. It has some numbered positions, and some positions half-way between the numbers. With even numbered threads you can close the half-nuts at any mark, numbered or not, and be on track for the next pass. For odd numbered threads, you select only the numbered positions, and for the rare fractional threads (like 11-1/2 TPI, you simply use the same number each time. If this is too much trouble to remember, you can *always* close on the same number -- it is just a little slower because you have to wait longer.

However, when cutting metric threads on a metric lathe with a metric leadscrew -- a single pick-up gear for the threading dial won't work. They have four separate gears, which require loosening the threading dial, tilting it out of mesh, sliding up or down until the proper gear is in place (determined by either looking up in the manual to the lathe, or squinting and looking it up on the threading data plate

-- if it is still legible), and tilt it back into mesh and lock it down. Only then can you start cutting threads. (Obviously, with CNC this all goes away, as it does with die heads on a turret lathe -- which you don't often find in a hobby machine shop.) Just one more operation to introduce possible error into the job. It is *this* additional complexity to cutting metric threads on a metric machine which I am talking about.

I cut my metric threads on a small CNC machine, so I don't have to deal with a threading dial there. So far I have not had to set up the transposing gears on the bigger machine.

Sometimes it is a tradeoff between screw strength (diameter) and the amount of material available for the screw to pass through. The more common imperial threads offer more intermediate steps for these situations. For most things, the standard metric sizes will work fine. But if you must stay metric, and hit one of those situations, it calls for a special thread which will cost you more. And -- it will offend your customers when they need a replacement screw and it has to be ordered from the factory at a high price. (Granted -- proper design should have avoided this problem -- but sometimes things are made as a retrofit, where the envelope of the product is defined by where it must fit, and not by what produces a strong enough design with standard screws.

Hardly -- but finding something like a M3.5 when a M3 is too weak, and a M4 results in too large a hole in the other piece, or threads close to breaking out the side of the threaded part.

O.K. I'll accept that. I really would not care if the foot, the yard and the mile went away as long as they left the inch. That would eliminate some of the complexity of the Imperial system which you are complaining about. When *I* am working in feet, it is usually something like the length of an extension cord, which does not have to be that precise as long as it is long enough.

Well ... most metric things try to avoid fractional sizes, thread diameter or thread pitch. this one is an exception.

O.K. The only place in the imperial screws (that I have experienced) where the design is really insane is the 6-32. It is too coarse a thread for its diameter, and thus weak -- resulting in more broken taps than any size larger or smaller. :-) Someone fell in love with the 32 TPI setting on their lathe, and kept it too long. 8-32 and

10-32 are quite reasonable threads, but 6-32 is not.

I never said it was. I was simply replying to the suggested claim that Imperial was more accurate than metric, and showing that it was not. Stop fighting me when I am arguing on your side. :-) I am simply discussing all points of the subject, not fighting for one side or the other. Each has its good points (based on the implementation, not the theory).

Of course. I never said that it did.

Enjoy, DoN.

Nope. I'm referring to the fact that there are 16 ounces in a pound and twenty ounces in a pint. It is an exact conversion because in the avadupois system we use here in Blighty, one fluid ounce of water weighs one ounce, exactly. It's a simple system really :-)

So as, I said:-

A pint of pure water weighs a pound and a quarter

Mark Rand RTFM

Admittedly, not too often to get bored with using the reverse for the next pass. On my small lathe, I have a VFD and crank it up to come to the start of the thread.

OK, it's a bit more complicated with metric. Three gears on the thread dial (28, 30, 32 IIRC) and only selected positions like 1, 4, 7 etc.

Accepted! :-)

Just pick a higher grade. :-) Standard is 8.8.

Picking a special thread (whatever that is, no one would make a M 7.2 just for that) is not the solution.

OK, lets see: M 1.6 M 2 M 2.5 M 3 : 4020 N M 3.5 : 5420 N M 4 : 7020 N M 5 : 11350 N M 6 : 16100 N

[M 3.5 should be avoided; I have no values below M 3] These are the minimum loads 'till failure with grade 8.8 screws. I mean, few are aware how much a M 3 can hold. Furthermore, the sizes increase in a geometric sequence (rounded). It is roughly 25% to the next bigger size. Do you want a finer granularity?

That's why the M 3.5 exists, but should be avoided. The step from M 3 to M 4 is 33%. Seems they realized that and added the M 3.5 for you. :-)

Then if you would quit the fractions, we are closer. What remains now is the conversion factor. No problem that much. But the much bigger problem is that there are two standards worldwide. The US of A is not an island. Double stock for screws, tools, .... And it also hurts *your* business. It was just yesterday when someone in a forum posted a link to a US-CNC mill (a smaller one $6k range). "Oh, imperial! Forget it!".

OK. I had to repeat that.

Sorry! :-) But it's no argument for any side. It's an "argument" that reveals the ignorance. NO, you did *not* say that!

Nick

Well, at least a minute is still a mile the world over, and thankfully thats something we can all agree upon!

Shaun

On Sat, 26 May 2007 21:42:13 -0500, with neither quill nor qualm, "Robert Swinney" quickly quoth:

Hey Swine, it's THE most powerful, bestest tasting rum I ever had the pleasure (when I was a drunk) to swallow. If I miss anything from my alcoholic days, it's rum, and Lemonhart (brand) was the stuff. The 151 indicated the proof I preferred. Kickass stuff, Maynard.

Da kine, mon.

- Metaphors Be With You -

If you are using a scale, the inch scale can be read to a finer dimension than a metric scale.

You can easily read a 64ths scale which is a finer dimension than a 1/2 mm scale. Anything finer than a half mm scale will be almost impossible to read.

But then who uses scales any more, with DRO's.

John

Here in Oz we use millimetres, centimetres, metres & kilometres with centimetres being used only because they are marked on rulers. When measuring I think 100 mm, not 10 cm, 1653 mm not 1 m 65 cm 3 mm, I think the standard measure used for house building is the mm

Alan

I prefer 100 - 60 - 100 vbg Alan, in Gosnells, Western Oz. VK6 YAB VKS 737 - W 6174

I think Japanese is simpler, less vowel sounds.

I learnt French at school but would have preferred to learn German

English is the premier world language because there are so many more words than any other language and so thoughts can be explained better with more precision.

Yeah, these days it seems to be 24-24-24.

Ah, the vagaries of law! When I worked on a Canadian research ship, we could order a 40 pounder (40 Oz.) of rum or Seagrams VO, whenever we went out into the Pacific for a period exceeding 48 hours. This was held in bond, on the ship. On the return to port, we got the stuff tax and duty free. $2.00 CDN for a 40 pounder of overproof VO was one heck of a good price!

Steve R.

or 1.653 M. I use mm and cm and M from time to time. Whenever I am into Physics or Science in general.

On the lathe I'm Imperial. Same on the Mill.

I've worked in both for 40 years or so now. I'm waiting for the next change myself.

Maybe a System Solar or System System.

Martin

Mart> >