Straight Edges

[Philly]

There is nothing wrong with having something in your workshop that you 100% KNOW is straight or flat. As anyone who has used a square which is not exactly 90 degrees will tell you, sometimes nearly straight isn't straight enough. :wink:
As to what tolerance we should work wood-be careful. You will be surprised how accurate your eye can be. And accumulative errors add up to BIG gaps.
Whilst I agree wood moves it also moves in a predictable way. I've never had a piece of timber move longer........ :wink:
Philly

 

[LyNx]

my wood moves longer :lol: :lol: :lol:

....hometime :arrow:

 

[Alf]

There is nothing wrong with having something in your workshop that you 100% KNOW is straight or flat.

Now if BB could be persuaded to venture outside the hand tools board he'd leap in here and point out that there's no such thing anyway - it's all a matter of tolerances :wink:

As to what tolerance we should work wood-be careful. You will be surprised how accurate your eye can be. And accumulative errors add up to BIG gaps.

Yebbut how often do you actually need a theoretical idea of straight? Big gaps are between two parts - so they need to fit square to each other, not to an idea of square. Or is this a hopelessly neanderthal way of woodworking and in fact another area where the machinery dictates to the woodworker... :roll: :wink:

Cheers, Alf

 

[Paul Chapman]

Yebbut how often do you actually need a theoretical idea of straight? Big gaps are between two parts - so they need to fit square to each other, not to an idea of square. Or is this a hopelessly neanderthal way of woodworking and in fact another area where the machinery dictates to the woodworker... :roll: :wink:

For me the problem of straightness is only really an issue when I have to use man-made boards - which I don't really enjoy using. Whenever possible I lip them with solid wood and I can then treat them more like 'proper' wood and fine-tune the components with hand tools.

Cheers :wink:

Paul

 

[davos]

Hi, I use an engineers straight edge for joining tops and backs of guitars as the way I was taught to join two pieces of wood was to clamp them together, plane them till they look straight, then take them out of vice hold them up to the window and if you can see light through the joint them you will see the glue line - which on top of a guitar looks rubbish. The trouble is if you haven’t got it right you have got to line the to pieces up again and start over again - to save doing this over and over again clamp two pieces together in vice, and plane till they look straight then put straight edge onto wood in vice and shine a light behind straight edge if it is not totally flat you will see light between straight edge and wood saves trying to line them up hope this makes sense cheers dave

 

[PaulH]

Thanks for all the replies. Basically I was looking at a straight edge to help accurately set up my new planer/thicknesser, rather than for wood itself.

However, it looks like I can save my 100 pounds! Hence why it's always worth asking the knowledgable members of this forum before making any purchase!

Thanks again,
Paul

 

[DomValente]

Six years ago my son("Dad that boards out a coupla mill.in 8ft.") an engineer, gave me a beautiful two foot steel rule, oddly enough including today I've used it twice.