CAD for simple 3-D metal & wood projects?

Probably not.

Leon fired this volley in news:56- snipped-for-privacy@giganews.com:

_I_ can, with woodworking tools. I built period reproductions of French Revival decorative furniture for about 20 years.

Except for a table saw, most of it with hand tools, per the authentic methods. Doing fit-ups to a thousanth is a must if joints were to be perfect. (and yes, I know about the growth of the wood, but some joints demand that precision)

No metal fasteners in them, either. Gauche'.

I can do dovetails you can't see a gap in by hand, too. Can you? I doubt it.

Lloyd

half a ten thousandths of an inch?

Yoicks, you're starting to get into the area where you can tell where it was, or how big it was, but not both.

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

Gunner Asch on Sat, 23 Nov 2013 10:47:05 -0800 typed in rec.crafts.metalworking the following:

You don't need CAD to make an original drawing.

But CAD sure comes in handy when you are attempting to make revisions to that drawing.

Somewhere I have the storage crate design for that ...

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

So except for when it was not, your work method used authentic methods. I suppose that means that you used the authentic methods when it suited you. It really does not matter what tool you use, it is the result that counts.

I use metal fasteners for knobs, and hinges and attaching adjustable feet on furniture that I design and build, that is about it.

Probably not, but with a router absolutely.

While we are bragging,

And with the exception of a couple of older pieces I have built all of these in the last three years and after I converted to Sketchup. AFWIW all joint details were drawn in Sketchup.

"Lloyd E. Sponenburgh" wrote in message news:XnsA28198C918BBDlloydspmindspringcom@216.168.3.70

Once you get them that way, how long does it take them to expand/shrink to something else?

Well, Lloyd, it appears Leon showed you his. How about you showing yours... to Leon.

-------------------------------------------- Most difficult when operating from a foot in mouth position.

Lew

Knowing nothing about aerospace I am willing to hazard a guess. I presume the space shuttle does not require tolerances anywhere near MILLIONTHS of an inch but I presume the shuttle's trajectory calculations would. I imagine that a rounding error would be the difference between a successful orbit or crashing into Homer Simpson's house in Springfield.

What is the tolerance for hydraulic spool valves?

I did too. The last post claims .000025" to .000040" clearance for aircraft valves.

jsw

"Jim Wilkins" fired this volley in news:l6suie$fts $ snipped-for-privacy@dont-email.me:

A few tenths, usually. And then, only that close when they pay really close attention to the coefficients of expansion of the spool and the frame.

Remember that there has to be enough room between parts to develop a film of lubricating (and sealing) oil, or they don't work.

There's an old (perhaps true) mythos about when Royce/Rolls first introduced an automatic transmission. They were adamant about making it to much tighter tolerances than "consumer" trannies, because they demanded the utmost in 'quality'. Then they discovered that the valve body and shuttles HAD to be sloppy in order to work at all.

Lloyd

John Browning's 1911 .45ACP:

With too tight tolerances, the pistol is unreliable in combat conditions due to mud, dirt, dust and the debris of a combat environment, and the guaranteed likelihood of not being able to keep it clean and lubricated on a regular basis.

That built in sloppiness sacrificed accuracy for reliability, but made for an excellent tradeoff for a weapon used mostly in close quarters.

Many years ago my shop foreman, that at one time lived in England and worked for Rolls, claimed that the engines used no head gaskets, the heads were bolted straight onto the blocks.

Likely jet engine parts but certainly not the galley cabinets.

Perhaps if the shuttle couldn't alter its trajectory (but orbital mechanics aren't known to that precision, anyway - three body problem). However, it does (did) have engines intended to make such corrections.

Leon fired this volley in news:j- GdncRZFoKltQ snipped-for-privacy@giganews.com:

My Deutz tractor is the same way. Precise construction. The heads are made with a shallow taper joint, and they bolt directly onto the cylinders (air-cooled, so the cylinders bolt TO the block, rather than being a part of it).

Lloyd

"Mike Marlow" fired this volley in news:l6tivv$efn$ snipped-for-privacy@dont-email.me:

Not for nothin', but precision bearings are machined to 10 microinches all the time -- and they're CHEAP!

Lloyd

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