GD&T and Shipbuilding

[Crablegs1]

Can anyone tell me if the application of GD&T in Shipbuilding is the same application as the Automotive Industry?

 

[Heckler]

ASME Y14.5M-1994

1.1 General - This Standard establishes uniform practices for stating and interpreting dimensioning, tolerancing, and related requirements for use on engineering drawings and in related documents.

I think this answers your question

Best Regards,

Heckler
Sr. Mechanical Engineer
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Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

 

[ctopher]

I agree.
It can be used for any type of mechanical design.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[looslib]

Yes on the surface that will work.
This is the area of ISO that I think works better.
ISO tolerancing is based on size and fit class.
A 25mm long part has tighter dimesnions than a 2500mm long part.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
Sr IS Technologist
L-3 Communications

 

[dingy2]

I have seen GD & T applied to nuclear generators so it certainly can be utilized in ship building.

The only problem comes in the confirmation methods. That could become a bit hairy since you probably have a 1 piece off situation and checking fixture may not apply.

Dave D.

 

[MikeHalloran]

GD&T might fly in military shipbuilding.

In recreational shipbuilding, they still haven't actually grokked the concept of interchangeable parts, so GD&T would be a complete waste of time.




Mike Halloran
Pembroke Pines, FL, USA

 

[KENAT]

GD&T was invented by shipbuilders, sort of.

I believe it was actually the part of the Royal Navy responsible for Torpedo Development.

looselib, I think you can achieve the same you just have to think about it a bit more. Plus there's more to GDT than size & fit class.

If you're in the US it's ASME Y14.5M, if the UK then BS8888, I'm sure other countries have there own standards.

BS8888 is essentially a list of all the relevant ISO, EN & BS specs and can be supplied as a kit.

So in essence I can think of no fundamental reason not to use it in shipbuilding.

 

[namdac]

Let's see as I remember that GDT came about during World War II and the reason was that when producing Tanks. The manufactuer would QC the parts and if they did'nt meet the spec at the time they were tossed. In a sense we were throwing away pefectly good parts. The part in question is the Tank Track.
Regards,
Namdac

 

[ctopher]

Some history:

http://www.iigdt.com/id81.htm

http://www-iwse.eng.ohio-state.edu/ISECourses/ise621/Sp00/GD&T1web.ppt#256,1,Engineering

Drawings

http://ieeexplore.ieee.org/iel5/8829/27951/01247857.pdf?arnumber=1247857

http://66.102.7.104/search?q=cache:mAohUZbcZkMJ:

http://www.csuchico.edu/~jpgreene/m...ppt+history+of+GD&T&hl=en&gl=us&ct=clnk&cd=83

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[KENAT]

I was reffering to the below item on drafting zone specific to GD&T as we know it today. Not general drafting standards or the concept of tolerance.

http://www.draftingzone.com/tips/tip39/

GDT actually came up just before WWII assuming Gary did his research, which I suspect he did.

I was taught that the issue of general tolerancing and quality control really came came to be an issue in WWI especially with respect to the size (calber) of shells etc.

 

[ewh]

I think it started developing earlier than that. In 1908, Henry Leland had won the Dewar's Trophy for technical innovation in 1908 by dismantling three of his Cadillacs, mixing up the parts, and reassembling the cars. Previous to that, he standardized the Colt pistol company to use interchangable parts.
It seems that the Singer sewing machine company had a hand in the early development of interchangability also, but I don't have any sources handy to show that.

 

[KENAT]

I'm talking GDT as a set of symbology etc.

The principle of interchangeability dates bact to at least the American Civil war think springfield and Enfield rifles.

It wouldn't surprise me if the Romans or something weren't into interchangeability but I doubt they had feature frames!

 

[ewh]

I guess I went off on a tangent!

 

[KENAT]

No problem ewh,I probably didn't explain myself well originally. Despite my excessive wordiness I still seem to leave things unclear.

Ken

 

[ctopher]

tan·gent (tnjnt)
adj.
1. Making contact at a single point or along a line; touching but not intersecting.
2. Irrelevant.


Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[thundair]

Mike

There is still advantages in tolerance studies and the use of MMC that has saved a few bad parts for me. Not to mention the 1.414 advantage over Cartesian coordinates.

Cheers





I know less and less every day

I don't know anything but the people that do.

 

[ringman]

Mike Halloran,

I vote with you. If there is not a requirement for interchangeability, GD & T would be pretty much a waste of time. And furthermore, most likely result in increased cost resuting from training those who have probably not had any exposure to it.