New square required!

[Derek Cohen (Perth Oz)]

The very best square is one made and available from Chris Wong in Canada.

The Magic Square ...

https://www.youtube.com/watch?v=dB0MBGiX8TQ

Regards from Perth

Derek

 

[D_W]

An accurate square should allow you to mark a shoulder line that lines up on all four sides of your square workpiece. If it doesn't it's not a lot of good.

John

Not the best test in the world. Your workpiece is far more likely to be out of square

Well, if you consistently end up with something good doing that, it's a reasonable test. Not necessarily mathematical proof, but good enough for a weekend woodworker. As you say, no guarantee that it's the square that's bad if the pieces don't line up, though.

 

[Peter Sefton]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

Try it out for fun.

Cheers Peter

 

[D_W]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

Try it out for fun.

Cheers Peter

It might not be ideal if you're looking for square, but it's a useful tip if you need to mark a shoulder on a piece of wood that doesn't need to be perfect on all sides.

 

[Peter Sefton]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

Try it out for fun.

Cheers Peter

It might not be ideal if you're looking for square, but it's a useful tip if you need to mark a shoulder on a piece of wood that doesn't need to be perfect on all sides.

It just shows a square can be inaccurate and give you a continuous box mark, but the shoulders are not square and problems will follow.

Cheers Peter

 

[D_W]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

Try it out for fun.

Cheers Peter

It might not be ideal if you're looking for square, but it's a useful tip if you need to mark a shoulder on a piece of wood that doesn't need to be perfect on all sides.

It just shows a square can be inaccurate and give you a continuous box mark, but the shoulders are not square and problems will follow.

Cheers Peter

Sometimes, one square pair (face and edge) is enough, and two more that are relatively close (visually) are fine. Especially if you're working by hand.

 

[John15]

An accurate square should allow you to mark a shoulder line that lines up on all four sides of your square workpiece. If it doesn't it's not a lot of good.

John

Not the best test in the world. Your workpiece is far more likely to be out of square

I did say square workpiece.

John

 

[MusicMan]

In the UK, "mil" is short for "millimetre".

In the context of speech, sure... But in written communication, that's what 'mm' is for.
But when I read, it my mind automatically thinks of 'mils' as in milliradians, where you have (by NATO standard) 6400 mils in a 360º circle.

when did NATO redefine pi? There are 2xpi radians in a full circle.

 

[bugbear]

In the UK, "mil" is short for "millimetre".

In the context of speech, sure... But in written communication, that's what 'mm' is for.
But when I read, it my mind automatically thinks of 'mils' as in milliradians, where you have (by NATO standard) 6400 mils in a 360º circle.

when did NATO redefine pi? There are 2xpi radians in a full circle.

Hmm. This story

https://en.wikipedia.org/wiki/Indiana_Pi_Bill

has pi at 3.2, which would lead neatly to 6400 (2 * 3.2 * 1000)

EDIT; Dead $DEITY. NATO and Indiana share the same view of maths.

http://www.metric-conversions.org/angle ... ersion.htm

BugBear

 

[MusicMan]

They'll repeal the laws of thermodynamics next.

 

[Tasky]

when did NATO redefine pi? There are 2xpi radians in a full circle.

Whenever NATO decided to derive it from SI units, I guess. 1950s?
I understand the French and Americans started using it in WW1, though...

They just rounded it from 6283.185 true milliradians to just 6400, to make things a touch easier for simple-minded mortarmen to place rounds accurately!!
The idea is that moving your point of aim by 1 mil at your end means the point of impact at the target end 1,000 metres away will move by 1 metre. Apparently it works just as well in yards, too!

Perhaps something could be implemented to measure how many mils out your square is?

 

[woodbrains]

Hello,

Don't American's use the word mills to mean thousandth of an inch?

I would always use mm ( at least say 'millis') and never say mills, it is very confusing!

Mike.

 

[Jacob]

An accurate square should allow you to mark a shoulder line that lines up on all four sides of your square workpiece. If it doesn't it's not a lot of good.

John

Not the best test in the world. Your workpiece is far more likely to be out of square

I did say square workpiece.

John

How would you know it was square?

 

[Tasky]

I would always use mm ( at least say 'millis') and never say mills, it is very confusing!

As with much of the English language, a lot depends on the context.
If it's clear you're talking in small, straight measurements, in an environment that commonly uses milimetres, then it's a reasonable assumption that 'mils' would be understood.... although I'd personally just say 'mil' myself, in the same way you might say 'foot' instead of 'feet'.

This solves the mil vs mils issue.

 

[John15]

How would you know it was square?[/quote]

Good point Jacob. I hadn't thought about that!

John

 

[John15]

I did say square workpiece.

John

How would you know it was square?[/quote]

Good point Jacob. I hadn't thought about that!

 

[Jacob]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

....

No it won't, unless you turn the square (or the wood). If you do all the marks the normal way with the square stock in your left hand, turning the wood, the marks will not meet. To bring them together, you'd have to turn it and use in your right hand for two of the marks, or turn the wood end to end.

Had to try this out to make sure!

OTOH the good news is - if the workpiece itself is perfectly rectangular* in section, then whichever way you apply a perfectly accurate square, the marks will meet.

*Or a perfect parallelogram. Doesn't do to overthink these things - everything becomes impossible!

 

[Peter Sefton]

If you set a sliding bevel out of square and mark around a section of timber always referencing off face side and face edge it will also give you a complete, but it will not be a square mark.

....

No it won't, unless you turn the square (or the wood). If you do all the marks with the square stock in your left hand, turning the wood, the marks will not meet. To bring them together, you'd have to turn it and use in your right hand for two of the marks, or turn the wood end to end.

Had to try this out to make sure!

OTOH the good news is - if the workpiece itself is perfectly rectangular* in section, then whichever way you apply a perfectly accurate square, the marks will meet.

*Or a perfect parallelogram. Doesn't do to overthink these things - everything becomes impossible!

As you say keep the stock of the bevel in your left hand, but it sounds like you didn't keep referencing off face side and face edge, if you just keep turning the timber you will draw a spiral.

Cheers Peter

 

[Jacob]

OOPS no I got it wrong! Sorry Peter. Yes if you do it the usual way the lines will meet. I was trying it out with hand and thumb - now had a go with an actual bevel.

 

[Peter Sefton]

OOPS no I got it wrong! Sorry Peter. Yes if you do it the usual way the lines will meet. I was trying it out with hand and thumb - now had a go with an actual bevel.

Thought I was going mad for a moment

Cheers Peter