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."
LOL, I was just making a point that in woodworking you don't need to work in tolerances that the human can't see. And The OP had on top of his list, drawing a board, not friggin atomic particles.
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?
I wasn't replying to your post specifically. I just wanted to get in my
2-cents about accuracy. As far as computers go, integers can match exactly, but not numbers with decimal points, in general. You can ask and get exactly 3 twobyfours, but not of any exact dimension! ; ) Of course, the value of PI can be matched exactly--just not by a typical computer. If one is willing to express numbers with base PI instead of base 10 or base 2, then all bets are off.
Well, Lloyd, it appears Leon showed you his. How about you showing yours... to Leon.
On Sat, 23 Nov 2013 15:17:28 -0600, Leon
Hi Leon. Got a question about Mary's bookcase. I can't tell from the pictures presented. In the back of the bookcase, I see you've put in columns in the centre of the shelving.
Are they inset into the shelving or is the shelving have a space behind it the full length of the shelving?
Hope I made my question clear.
-------------------------------------------- Most difficult when operating from a foot in mouth position.
Lew
In Windows 7 I noted, in a solitary game 7 out of 10 score is 69%. Garbage in garbge out.
Mark
.7 can't be stored exactly as such as a floating point number on a typical modern computer. Someone "casted" the number to an integer, losing what what stored as a fraction.
They used: (int)(average) when they should have used: (int)(average+.5).
The latter would have rounded.
Ayup...aerospace requires 50 millions or half 10ths all the time.
Which is damned hard to do with machines that hold +/- 2 tenths
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
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.
The back of the cabinets have face frames also. The back face frames however are assembled with lap joints that join with the rabbets on the inside edges. The center back stiles are part of the back face frame and it too has rabbets. The rabbets are 1/2" deep and 1/2" wide. The back panels fit in to the rabbets from the back side.
Soooooo the shelves have a straight back edge that butts up against the outer and center stiles of the back face frames and there is a 1/2" gap between the panels and the back edge of the shelves.
Clear as mud? LOL
If you are using Sketchup I can send you a drawing for to look at more closely.
Hardly impossible. It happens many thousands..hundreds of thousands of parts a day.
Jet engine parts, microwave wave guides, thousands of things. Most of which I was not cleared to know what they were when I ran into them.. An awful lot of optical stuff is that or more.
Shrug. And a lot of that stuff I figured would be good at
+0/- .001...but..the specs...As the truism goes...the more zeros you add to the right of the decimal point...you multiply the cost by a factor of 5-10
__ "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
On Sat, 23 Nov 2013 23:47:12 -0600, Leon
No need to send me a Sketchup file, I understand perfectly. But, your explanation leads me to a few more questions. Are the back face frames for support, visualization, a combination of both or maybe something else?
And, how are you fastening the back panels? If the back face frames are 3/4" initially, removing a rabbet of 1/2" leaves only 1/4". I'm guessing some type of glazier points or something similar?
Thanks.
Half a thou? (NOBODY says 50 millionths!) Integrated circuit transistor sizes run less than 200 nanometers. (for CAD tolerance, not wood working, ok? Sheesh!)
Mike, as to getting to orbit, the precision required is nowhere near that tight. It's actually fairly sloppy for a successful orbit. SPEED it the key player there, not trajectory. 20,000 MPH straight down the east bound lane of I-30 will do just fine. It won't be a circular orbit, but you won't be back any time soon. :)
A lot of it has to do with rates of expansion and contraction between different metals. If a part that has a hard alloy piston contracts more than the piston does when its -250F (outer space)....its nice to know that the critter isnt going to bind up after its in orbit...so fits are carefully calculated.
Notice the old SR-71 leaked fuel like a freaking sieve when it was on the ground..but after the fuselage heated up in flight..all the cracks closed up nicely and the fuel leaks stopped. Hence the SR-71 needed to be refueled after takeoff run..then it would go like a sombitch around the planet before needing another refueling.
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
Half a thou isnt 50 millionths. Its only 5 tenths. 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
Hi Leon,
What is this:
??
I assume it's something to do with sewing due to the cotton reel, but my tiny mind can't imagine what the whole thing would be for (which isn't a shock, really!)
Cheers.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.