Do I need a straight edge?
- Thread starter xraymtb
- Start date
Help Support UKworkshop.co.uk:
YorkshireMartin
Established Member
Personally, I use one for all manner of things and definitely wouldn't be without one for what I do. I guess it depends on what you already have, but I think a straight edge is an essential workshop tool. Others may disagree.
Jacob
New Luddism. Wake up and resist.
No you don't need one. It's not a woodwork tool. Woodworkers make their own if needs be, but more often just use a long spirit level (if they happen to have one).
To check a plane sole for flatness; retract the blade and work the plane up and down a bit of fine wet n dry (on a flat surface) for a few seconds. Instantly obvious. Not necessarily anything to worry about - it's only when there are problems in use that you might wonder about the flatness of the sole
To check a plane sole for flatness; retract the blade and work the plane up and down a bit of fine wet n dry (on a flat surface) for a few seconds. Instantly obvious. Not necessarily anything to worry about - it's only when there are problems in use that you might wonder about the flatness of the sole
No skills
Established Member
Handy to have if you have spare money to spend, but as Jacob says a good spirit level works for lots of things.
I generally work to "if it looks right it is right" rather than some of the nano measurements that some wood engineers work to so take my answer with that perspective.
I generally work to "if it looks right it is right" rather than some of the nano measurements that some wood engineers work to so take my answer with that perspective.
Sure one can get by without but they are so useful. As you say for checking and aligning surfaces but also good for cutting veneers and they can be carefully bent to draw curves. Trying to check flatness of a surface with a level that has 20-25mm wide base is so much harder than the fine edge you get on a good straightedge.
Jacob
New Luddism. Wake up and resist.
Not if you've been bending it to draw curves!!Beau":1p0gpypz said:
You use a fat straight-edge (like a spirit level) tilted on edge. It's going to be straighter than a bendy flat straight edge - only usable flat; for drawing lines or cutting card etc.
Jacob it's easy to hold a thin straightedge on it's edge for a reference. Drawn curves with mine for years and it's still fine. Levels are usually made of soft aluminium so easily get marked and dented so no longer a good reference. My straightedge is stainless and hard so almost like new after 25 years. And why should we all have a long spirit level? For woodwork I would say a straightedge is far more useful than a long level anyway so if trying to keep things simple I would go for a straightedge first and not buy a level unless doing lots of site work.
Jacob
New Luddism. Wake up and resist.
If it's the slightest bit bendy then it won't be reliable on edge.Beau":23gryt2q said:
Jacob":16qutaf1 said:
It is and your wrong
It's not this flexi though http://www.dmmiller.co.uk/pajarito-no21 ... -edge.html
Jacob
New Luddism. Wake up and resist.
If there is a bend in it then it could lie flat on a curved surface so unless you can hold it dead straight it is unreliable. The usual thing with a bendy straight edge is to tilt it one way and the other to get best fit, which just isn't going to be as reliable as a dead rigid edge.Beau":2no6xui3 said:Jacob":2no6xui3 said:
It is and your wrong
It's not this flexi though http://www.dmmiller.co.uk/pajarito-no21 ... -edge.html
Jacob
New Luddism. Wake up and resist.
Not as cheap as just planing up an off-cut.Racers":h9hzc8m8 said:
Beau":1ojs13r1 said:
It is and your wrong
How can it be ? the edge you are using isn't in the same plane as it should be - it's following a curve.
Only buy a spirit level for site work? You don't use one in your house, then?
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 74
You're at it again Jacob!
Most people don't do silly things with a precision straight edge. I have a couple of 600mm (2') stainless rulers that can be bent to gentle curves, and serve as "secondary" references, but I wouldn't dream of doing that to my Axy 750mm straightedge.
It's thick enough to sit on edge (and intended to do that). I hardly ever use the bevelled edge, but would be frustrated without it for a few purposes. Here's some of the stuff I do with it:
- checking the height of the insert plate on the router table (by bridging it with the straightedge and shining a light from behind),
- checking the fence bracket alignments (originally a split fence design that's never used that way and occasionally goes awry),
- checking the planer tables,
- checking/setting the bandsaw table (can twist because of the blade slot, which is awkwardly in front of the blade),
- checking plane soles, etc.
- "extending" the table saw blade for alignment purposes.
... and so on.
My 2' spirit level is great, but very slightly (and annoyingly) bent into an inverted U shape nowadays (30+ years old now). Over the years the edges have got so damaged I wouldn't/couldn't use it for a straigtedge, although I do occasionally use the back of a plunge saw rail for marking out (but that too doesn't have an arris).
[Edit]I wouldn't buy an aluminium straightedge as such, as it's too easily damaged - anodising hardens the surface a bit, but milling an anodised extrusion reveals the softer aluminium underneath (so you're back to where you started, i.e. too soft).[/]
The Axminster straightedges used to be very good value, but I haven't needed to replace mine (as I look after it), so I don't know nowadays. [Later] Just looked: it's now around 1/3 more than I paid for mine, which is a shame (but still better value than an aluminium one as it won't wear half as fast) [/].
The weight is useful too - it stays put readily and the shape is surprisingly good - stands on its reference, squared-off edge for the planer tables, etc. Of course you could use a planed offcut to draw lines with, but a proper straightedge is quick and easy, and most importantly, known-good.
Have fun with offcuts, but I'll stick with my straightedge, thank you.
E.
PS: I have two lengths of ground silver-steel bar stock, 1/2" and 1/4" diameter. These are used for router and drill press alignment (a tilting drill press table is both a blessing and a curse). They're much easier than trying to get a square to line up along a large twist drill bit.
Most people don't do silly things with a precision straight edge. I have a couple of 600mm (2') stainless rulers that can be bent to gentle curves, and serve as "secondary" references, but I wouldn't dream of doing that to my Axy 750mm straightedge.
It's thick enough to sit on edge (and intended to do that). I hardly ever use the bevelled edge, but would be frustrated without it for a few purposes. Here's some of the stuff I do with it:
- checking the height of the insert plate on the router table (by bridging it with the straightedge and shining a light from behind),
- checking the fence bracket alignments (originally a split fence design that's never used that way and occasionally goes awry),
- checking the planer tables,
- checking/setting the bandsaw table (can twist because of the blade slot, which is awkwardly in front of the blade),
- checking plane soles, etc.
- "extending" the table saw blade for alignment purposes.
... and so on.
My 2' spirit level is great, but very slightly (and annoyingly) bent into an inverted U shape nowadays (30+ years old now). Over the years the edges have got so damaged I wouldn't/couldn't use it for a straigtedge, although I do occasionally use the back of a plunge saw rail for marking out (but that too doesn't have an arris).
[Edit]I wouldn't buy an aluminium straightedge as such, as it's too easily damaged - anodising hardens the surface a bit, but milling an anodised extrusion reveals the softer aluminium underneath (so you're back to where you started, i.e. too soft).[/]
The Axminster straightedges used to be very good value, but I haven't needed to replace mine (as I look after it), so I don't know nowadays. [Later] Just looked: it's now around 1/3 more than I paid for mine, which is a shame (but still better value than an aluminium one as it won't wear half as fast) [/].
The weight is useful too - it stays put readily and the shape is surprisingly good - stands on its reference, squared-off edge for the planer tables, etc. Of course you could use a planed offcut to draw lines with, but a proper straightedge is quick and easy, and most importantly, known-good.
Have fun with offcuts, but I'll stick with my straightedge, thank you.
E.
PS: I have two lengths of ground silver-steel bar stock, 1/2" and 1/4" diameter. These are used for router and drill press alignment (a tilting drill press table is both a blessing and a curse). They're much easier than trying to get a square to line up along a large twist drill bit.
I don't think we're discussing whether straight edges are good - of course they are - so much as whether they are necessary. A straight edge is perfect for many of the jobs mentioned up the now - but as Jacob says there aren't many that can't be done perfectly well with something else and there is little point in using an imperfect straight edge. My one metre Stabila level (that I bought second hand for £15 thirty years ago ) gets used for most things - I may eventually come across something that stymies me for want of a straight edge, but it hasn't happened in the last fifty years.
Of course if the OP was spending his working week veneering or something he would find a good straight edge a day to day tool - but he wouldn't then have asked the question.
) gets used for most things - I may eventually come across something that stymies me for want of a straight edge, but it hasn't happened in the last fifty years. Of course if the OP was spending his working week veneering or something he would find a good straight edge a day to day tool - but he wouldn't then have asked the question.
This is why I would recommend a straight edge over a level for checking machines etc.
I know the tables on my PT are not quite aligned so some pictures to show how much easier it is to check this with the right tool.
Sabila level
Straight edge on the thick edge
Straight edge on tapperd edge
And some naughtiness. Not all straight edges may be up to this.
I know the tables on my PT are not quite aligned so some pictures to show how much easier it is to check this with the right tool.
Sabila level
Straight edge on the thick edge
Straight edge on tapperd edge
And some naughtiness. Not all straight edges may be up to this.
Attachments
Eric The Viking
Established Member
- Joined
- 19 Jan 2010
- Messages
- 6,599
- Reaction score
- 74
Rather you than me!
I can achieve the same with a steel rule, without risking doing it any permanent damage.
I can achieve the same with a steel rule, without risking doing it any permanent damage.
Jacob
New Luddism. Wake up and resist.
What you do is cant the spirit level on edge.
Your bent straight edge could give wrong results unless it's guaranteed to spring back dead straight
It's not a particularly good way to draw curves either in that they will be compound "catenary" curves (or some such name) and if you did it too often you'd permanently spoil your straight edge - it'd never be straight again and it'd not do a symmetrical curves.
Your bent straight edge could give wrong results unless it's guaranteed to spring back dead straight
It's not a particularly good way to draw curves either in that they will be compound "catenary" curves (or some such name) and if you did it too often you'd permanently spoil your straight edge - it'd never be straight again and it'd not do a symmetrical curves.
bugbear
Established Member
Jacob":3m8tj18b said:
That would only work if the face is ground accurately, since the arris you're using is the intersection of 2 planes (edge and face); they'd both need to be accurate for the arris to be accurate.
I don't think the makers of spirit levels certify the accuracy of the face, although it may be good enough for joinery work.
BugBear
