Previous in Forum: Pump Presser   Next in Forum: Conversion
Close
Close
Close
17 comments
Rate Comments: Nested
Anonymous Poster

Engineer

08/18/2010 4:54 AM

How to generate a straight line. For instance, using a straight edge such as a ruler is copying assuming the straight edge is straight.

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#1

Re: Engineer

08/18/2010 5:04 AM

It depends entirely on what you want to do with the 'line'.
If it's the centre line on a wooden bow stave split from a log, then a rough pencil line following a taut string is adequate.
If it's a part of a jet engine then something created by a CNC machine or laser is probably more appropriate. It's all about context.
A straight line can also just exist virtually by defining it's ends.
KrisDelTM can supply a huge variety of virtual lines specially coiled for easy shipping.
Del (I like playing with string)

__________________
health warning: These posts may contain traces of nut.
Reply Score 1 for Good Answer
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9684
Good Answers: 468
#2

Re: Engineer

08/18/2010 5:05 AM

1) Take one piece of string, longer[1] than the straight line you wish to generate.

2) Apply tension. Do not exceed breaking strain of string. If you're really fussy, do it in zero gravity (free fall would be OK) and under vacuum.

[1] This is to allow the ends of the string to be grabbed/clamped/tied/nailed or otherwise secured.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#3

Re: Engineer

08/18/2010 5:21 AM

Draw one line with the alleged straightedge. Turn it over and draw another line more or less coincident with the first.. If the two lines diverge, just split the difference. Take a look first for dings and scratches, and adjust accordingly. Rinse and repeat until results are satisfactory.

This is what I was taught in Metrology 001, and far be it from me to dispute my illustrious professor.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4884
Good Answers: 243
#4

Re: Engineer

08/18/2010 7:50 AM

mount laser on ball head of tripod. point at surface the line is to be on.

turn on laser.

place small mark at top of indication on the surface move incrementally.

repeat as needed.

join the dots.

Del was that 'virtual line product' coiled for 'shipping' or for 'shaping?'

Milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#7
In reply to #4

Re: Engineer

08/18/2010 9:28 AM

...was that 'virtual line product' coiled for 'shipping' or for 'shaping?'
Errr, ummm, the ones for 'shaping' command I higher price I believe.
I shall hve to consult my board of directors, when I can find him.
Del

__________________
health warning: These posts may contain traces of nut.
Reply Off Topic (Score 5)
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5363
Good Answers: 647
#5

Re: Engineer

08/18/2010 7:58 AM

Are you talking about a Euclidian or non-Euclidian straight line? Inertial or non-inertial frame of reference? How many dimensions is the space containing the line? Is the line supposed to be timelike or spacelike? Do you need the entire line, or just a segment of a line?

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Reply
Anonymous Poster
#16
In reply to #5

Re: Engineer

08/25/2010 11:59 AM

The intention is to generate a straight line on a flat surface. A compass generates a circle - there's the clue!!!!

Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9684
Good Answers: 468
#17
In reply to #16

Re: Engineer

08/25/2010 5:46 PM

I know - I know! A pair of compasses with legs of infinite length!

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply
Guru

Join Date: Aug 2009
Location: Glen Mills, PA.
Posts: 2385
Good Answers: 114
#6

Re: Engineer

08/18/2010 8:47 AM

You hold the straightedge up, pointed away from your eye, and look along its length. You will be able to see if it is straight. If not, hit the shorter side, not at the very edge, with a ball peen hammer to make it stretch a little and so straighten the ruler. Repeat until it is satisfactorily straight.

__________________
In a time of universal deceit, telling the truth is a revolutionary act. George Orwell
Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#8
In reply to #6

Re: Engineer

08/18/2010 9:30 AM

My metre rule is now 1050mm long with an attractive scalloped edge....where did it all go wrong
Del

__________________
health warning: These posts may contain traces of nut.
Reply
Guru
Hobbies - DIY Welding - Don't Know What Made The Old Title Attractive... Popular Science - Weaponology - New Member United States - US - Statue of Liberty - 60 Year Member

Join Date: Apr 2009
Location: Yellowstone Valley, in Big Sky Country
Posts: 7425
Good Answers: 295
#9
In reply to #8

Re: Engineer

08/18/2010 10:01 AM

A possible new item, then, for KrisDel™ Industries: Fiddlebow Breadknives!

__________________
Semper Ubi Sub Ubi
Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#15
In reply to #8

Re: Engineer

08/20/2010 3:12 AM

Well, you shouldn't have hit it that hard (too bigga hammer). Novices....

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8777
Good Answers: 376
#10

Re: Engineer

08/18/2010 3:31 PM

Every CAD drawing package can draw a perfectly straight line every time. For a hard copy use the print function.

Is this what you were after? I cannot think of any situations that cannot be handled by either a CAD drawing, metal ruler or laser pointer. Are you talking about lining up a staright line with other objects?

Can you please explain your application in a little more depth.

__________________
jack of all trades
Reply
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4884
Good Answers: 243
#11
In reply to #10

Re: Engineer

08/19/2010 12:14 PM

Its actually a wonderful ontological engineering paradox.

How does one intitially"generate" a straight line if one does not have "straight" lines to derive the "straight " from.

I really loved the "Euclidean noneuclidian" comment, it helped me see this as more a thought experiment...

Milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#12
In reply to #11

Re: Engineer

08/19/2010 12:47 PM

My mate René says if he thinks it's straight, it must be.
With my arrows I notice if they are bent when I hit full draw...too late then, it's gone.
Sproing................................................. thwack
Del

__________________
health warning: These posts may contain traces of nut.
Reply
Guru

Join Date: Jul 2006
Location: "Dancing over the abyss."
Posts: 4884
Good Answers: 243
#13
In reply to #12

Re: Engineer

08/19/2010 1:01 PM

" It's what happens when the errors ain't straight"

Whenthesteelbarsarentstraight

Milo

__________________
People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe
Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#14
In reply to #13

Re: Engineer

08/19/2010 1:06 PM

...

__________________
health warning: These posts may contain traces of nut.
Reply
Reply to Forum Thread 17 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); Doorman (1); jack of all trades (1); JohnDG (2); Milo (3); passingtongreen (1); Tornado (2); Usbport (1); user-deleted-1105 (5)

Previous in Forum: Pump Presser   Next in Forum: Conversion
You might be interested in: Edge Trims and Trim Seals, 3G, UMTS and EDGE Chips

Advertisement