Is it normal for a straight edge to be doing this?

[iNewbie]

Straightedges do not have scales - they are straightness references, not rulers.

Doesn't that really depend on what a company manufactures. Starrett make them with a Graduated Edge and made tp a fine tolerance. More a case of: a straightedge can have a scale

Not familiar with the particular Starrett product you mention, but it sounds a bit like those straight-backed handsaws you could buy with a scale etched along the edge. Nice idea in theory, but most people buy a saw for sawing, and use their two-foot folding or tape for measuring. The scale doesn't do any harm, but it probably doesn't do that much good either for most people most of the time.

I guess it depends on what someone is using it for. You can use a scribe with the starrett - so no slithers issue.

4 ft one is $600 and the market is obviously there as they've sold them for years.

http://www.starrett.com/metrology/produ ... ols/387-48

 

[Cheshirechappie]

I note out of 21 models of straightedge, only 3 have graduations.

You can run a scribe along any rectangular section steel straightedge, but over time it will wear. Given that most work tends to be concentrated towards the middle of most straightedges, they tend to wear hollow.

One workshop I had a voluntary work connection with had a load of metrology equipment donated by a downsizing engineering firm. Among the kit was a 6-foot straightedge which somebody had etched '10thou hollow' on the side of, and an arrow at about the mid-point. Handy, because at least we knew it was out of whack, and didn't 'assume' it was true!

 

[iNewbie]

3 out of 21? At those prices I don't think everyone can afford 'em! LOL

 

[Jacob]

I note out of 21 models of straightedge, only 3 have graduations.

You've missed out hundreds of models of ruler - they have straight edges and gradations. You could call them "graduated straightedges" if that'd cheer you up.

 

[Jacob]

..... The scale doesn't do any harm, but it probably doesn't do that much good either for most people most of the time.

They come in handy if you want to measure something.

You haven't answered my earlier question - was the OP's wotsit a "straightedge", a "straight edge" , a bit of a banana, or all three?

 

[bugbear]

I note out of 21 models of straightedge, only 3 have graduations.

Of course - because in engineering you don't measure or set out (accurately) with graduations, you measure with dividers, calipers, or micrometers, or gauges; a straight edge's sole purpose is for being straight in 1 dimension (a surface place is straight (planar) in 2 dimensions).

Even going back a century, when woodworkers made their own straightedges, by careful planing of well seasoned mahogany, checked against each other in pairs or triples, they didn't put gradations on. You don't gradations when checking a workpiece for flatness.

It's a straight edge.

Conversely, woodworkers traditional 2 fold and 4 fold rules are terrible straight edges...

BugBear

 

[Jacob]

.......
Conversely, woodworkers traditional 2 fold and 4 fold rules are terrible straight edges...

BugBear

True but on the other hand an average one piece ruler, if not too bendy, may be a very good straightedge.
They can be both you know, though this might seem like impossible multi-tasking to some! :lol:

 

[Beau]

.......
Conversely, woodworkers traditional 2 fold and 4 fold rules are terrible straight edges...

BugBear

True but on the other hand an average one piece ruler, if not too bendy, may be a very good straightedge.
They can be both you know, though this might seem like impossible multi-tasking to some! :lol:

Not my experience.

Both the 600mm and my 1000mm Rabone Chesterman steel rules are definatly not straight. IMO if you want a straight edge buy a straightedge.

 

[Jacob]

.......
Conversely, woodworkers traditional 2 fold and 4 fold rules are terrible straight edges...

BugBear

True but on the other hand an average one piece ruler, if not too bendy, may be a very good straightedge.
They can be both you know, though this might seem like impossible multi-tasking to some! :lol:

Not my experience.

Both the 600mm and my 1000mm Rabone Chesterman steel rules are definatly not straight. IMO if you want a straight edge buy a straightedge.

Well I said "may be". The OP bought a "straight edge" which ain't straight

 

[Beau]

[/quote]Well I said "may be". The OP bought a "straight edge" which ain't straight[/quote]

Haha yes forgotten where we had started.

 

[Wizard9999]

Haha yes forgotten where we had started.

Seems to me that this thread has little to do with the OP's original question anymore. Rather it is more an interesting insight into the human psyche, which is coincidentally being facilitated by a discussion about straightedges or straight edges. But it makes for a jolly amusing read.

Terry.

 

[Zeddedhed]

Rather it is more an interesting insight into the human psyche, which is coincidentally being facilitated by a discussion about straightedges or straight edges. But it makes for a jolly amusing read.

One day we'll find out that UKW is a University Psychology experiment and we're all unwitting participants.

 

[Jacob]

......
Even going back a century, when woodworkers made their own straightedges, by careful planing of well seasoned mahogany, checked against each other in pairs or triples, they didn't put gradations on. You don't gradations when checking a workpiece for flatness.......

Woodworkers still "make" their own straightedges i.e when called for, press into use any handy straight piece of wood, or anything , planing it straight if necessary. We judge it straight by squinting down it with one eye.

The engineers precision edge isn't part of the woodworkers armoury as a rule (no pun intended) and the matching up of pairs/triples which BB describes is a precision engineers trick.
Though straightedge does get a brief mention in Salaman but they don't feature in woodworkers inventories or tool collections.
The same could not be said of sharpening jigs of course - they don't even get a mention; they didn't exist at all until recently. :roll:

Anyway, to change the subject, what about a swiss army knife? Is it a knife, a pair of tweezers, or a bottle opener?

 

[bugbear]

The engineers precision edge isn't part of the woodworkers armoury as a rule (no pun intended) and the matching up of pairs/triples which BB describes is a precision engineers trick.?

Woodworkers can have some knowledge of Euclid too, you know.

I'll post the cite/reference to wooden straight edges being checked in sets next time I run across it - I've got enough old WW texts that, whilst I can readily recall the techniques and detail, I can always remember which book it was in.

But I'd hate to be accused of making stuff up just to suit an argument.

BugBear

 

[Jacob]

BB I'm not saying that woodworkers didn't do what you say or that you are making it up, I'm just pointing out (again) that a (precision, purpose made, engineers) straight edge isn't really a woodworkers tool at all.

 

[Wizard9999]

...Woodworkers can have some knowledge of Euclid too...

Please let this debate move onto non-Euclidian geometry, that will make discussion of a straight edge / straightedge really esoteric. :lol:

Terry.

 

[Sporky McGuffin]

Please let this debate move onto non-Euclidian geometry, that will make discussion of a straight edge / straightedge really esoteric. :lol:

Similarly, I'd be very interested to learn how others are dealing with local space-time distortion in their workshops. It's the bane of the modern woodworker.

 

[Wizard9999]

Well said sporky. The fact that when I put a piece of wood through my table saw time when viewed from the perspective of the blade is moving ever so slightly slower than it is from the perspective of the piece of wood itself has always troubled me. :lol:

Terry.

 

[Cheshirechappie]

Please let this debate move onto non-Euclidian geometry, that will make discussion of a straight edge / straightedge really esoteric. :lol:

Similarly, I'd be very interested to learn how others are dealing with local space-time distortion in their workshops. It's the bane of the modern woodworker.

For the Astro-Physicists among us, String Theory can be relevant in the workshop. If you need a long straight line, take a ball of string, stretch it tight between the two endpoints, chalk it well, then twang it. Of course, if you need an even curve, you'll have to find a ball of bent string.

 

[Cheshirechappie]

Worth recalling the Clifton story, here. It's said that when Clifton were still under the Clico umbrella, they once received an irate phone call from a customer complaining that his brand new plane sole was not straight when checked with his straightedge. The staff then had the task of finding a diplomatic way of telling him that he just discovered that the plane sole was straighter than his straightedge....