3

While posting a question, I knew that a tag that would be valuable would be a tag that reflected the question was specifically about the trueness of the joints, whether they were square, plumb, proud, etc. Is there a term for that type of verification? I thought about precision or maybe accuracy but neither of those felt quite right. Does anyone have an idea for what this tag might be named or am I just completely off base to begin with?

| |
  • I'm thinking this might even need to be a hyphenated tag, like strong-true or something similar. Just a thought. – Pᴀᴜʟsᴛᴇʀ2 Mar 20 '15 at 22:12
  • 1
    I'm not sure if any one tag would be well-known enough to be re-used. Perhaps [craftsmanship]? Seems kind of like a one-off tag no one else will think of using though. I call it [fit-and-finish], but I'm not sure anyone would seek that out, either. – Robert Cartaino Mar 21 '15 at 0:45
  • Using those tags as aliases would not hurt anyone. I don't see these examples standing out on there own per se. precision feels right to me with accuracy as a synonym. quality might be a stretch since it is very vauge but worth considering. Robert might have a point but It could add context to a tool question. The tag would never be used on its own but partnered with a tool it could be valuable. – Matt Mar 21 '15 at 2:36
  • Hey peter.. Community bumped this. Are you still seeking advice for this? – Matt Apr 30 '15 at 15:43
2

This is referred to as geometric dimensioning and tolerancing.

Different geometric characteristics can have different tolerances. You find them in technical drawings in mechanical engineering.

You are probably not familiar with them because outside of engineering, people are not used to the units and numbers used. They are often hard to imagine.

That's why they are expressed by making comparisons to more commonly known objects.

this sphere for example

enter image description here

These spheres are among the roundest man-made objects in the world. If the best of these spheres were scaled to the size of Earth, its high point—a continent-size area—would rise to a maximum elevation of 2.4 meters above "sea level".

That gives you an idea of how much it differs from being a perfect square.

Compare it to this wording of the tolerance in technical terms:

The sphere shown in the photograph has an out-of-roundness value (peak to valley on the radius) of 50 nm.

You are probably more familiar with the imperial system, so an "m" (meter) is unfamiliar ground. nm means 0,000000001m that's 1 nanometer, that is 3.93700787 × 10^8 inches

As you can see, it only makes sense to specify the tolerances if they are very tight and the manufactured object is something very precise. Nothing you really come across in woodworking.

However, the term still holds its meaning regardless of the numbers. You can specify tolerances as tight as you want. In woodworking, you might specify an out-of-roundness value of 5mm (~ 1/5 of an inch).

Suggestion for the tag

Create the tags tolerance and dimensioning as synonymous. Time will tell which phrase people will use more often.

or:

I'm not sure how well the tag search works (you enter a part of the tag an it shows you you all that contain that part), but maybe the tag should be geometric-dimensioning-and-tolerancing with GD&T as synonym. Im in hope that typing any of the words included would bring the tag up.

| |
  • Dimensioning has another connotation in woodworking, but I like tolerance. – rob Apr 30 '15 at 20:26
  • @rob what is that other connotation? – null Apr 30 '15 at 21:18
  • 1
    "dimensioning" lumber usually involves surfacing 2 or more sides and milling to rough dimensions; e.g., jointing one face, jointing one edge, then planing the other face parallel to the first face and ripping the other edge parallel to the first edge – rob Apr 30 '15 at 22:30
  • @rob that's actually the same connotation as the one in the article: modifying an object (its properties) so that it is within the tolerance. You do not specify the tolerance explicitely, but you joint the face in order to improve the flatness of it, which implies that the required tolerance for that is tighter. – null May 1 '15 at 8:29
  • You're right; dimensioning, as it is used in the article, is used similarly to initial stock dimensioning, which is why it confuses me that you originally suggested the two terms are used interchangeably in the article. The two terms are different but related concepts, and they are not synonyms. Again, I like tolerance for discussing tight-fitting joints, but I do not think dimensioning is very helpful for describing tight-fitting joints. – rob May 1 '15 at 15:24
  • @rob in my language, peter's term would be the literal translation of "geometric tolerances" and while that literal translation covers the meaning, I could not find that on wikipedia, which made me wonder if that's actually a common used term (which is important for a tag) But when I google'd for "geometric tolerance" I get that GD&T thing as a result, which made me think this is indeed the common term, despite the different meaning of both words it is made up of (which you are pointing out.) I guess it's because you can rarely talk about one thing without the other. Sorry for the confusion. – null May 1 '15 at 18:02
  • I like tolerance and will use that going forward for this type of question. – Peter Grace May 4 '15 at 13:43
1

I would say you used the term you need in your question - trueness In 'Understanding Wood', Bruce Hoadley defines trueness: "Trueness compares the actual to the intended geometry of the surface". So, I would vote for that.

Having said that, this is a new forum and woodworkers come from a wide range of backgrounds, so tags like 'craftsmanship' or 'precision' are useful.

So I suggest using several tags, and letting some time pass. After a while, it should be more obvious which tags work well and some kind soul will cull a tag or two here and there to help clean up the site.

| |

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .