Xy's Pencil Gauge

[woodbloke]

The best tool to do this sort of thing is a mini drill or grinder such as the Proxxon or Dremel, equipped with a selection of small grinding wheels. The flat is easy enough to grind but the rear curved section needs to be relieved so it's not quite so 'fat' if you see what I mean and then shaped carefully with the wheels so that there's an edge where it meets the 'flat' The cutting tip should also form a slight curve rather than a sharp point. Difficult to describe but easy enough to do with a little bit of practice - Rob

 

[xy mosian]

Thanks Rob, I think I get it.

As I see it. An angled flat on the circular section of the point will produce an elliptical shaped section. With a near sharp point where the section cuts the 'back' of the point body. This depending upon the angle of the flat to the axis of the point body.

I believe you are suggesting that the body behind this flat is shaped to produce a 'knife-like' edge where the flat meets the body of the point. This will reduce the amount of 'meat' behind the flat resulting in a thinner blade. At the same time reducing the sharpness of the point slightly will ease the use of the point in wood.

Sounds good to me!

xy

After thought. Somewhat like a flat formed on the 'flat' side of an elliptical section bar? Oval nail for example.

xy

 

[bugbear]

There are some (in some cases asbtruse) thoughts on gauge blades in this thread:

https://www.ukworkshop.co.uk/forums/view ... sc&start=0

Edit; damn the most important two links are both OOD.

Here's updates:

http://swingleydev.com/archive/get.php? ... =1#message

BugBear

 

[xy mosian]

Bugbear, phew and thanks. I thought 'I'll just make a marking gauge'.

Hey it's all good stuff.

I think for my use, and possible required accuraccy, then going to the extent of worrying about which side the bevel is, on a marking gauge, would be going a little too far. I can well see that I would easily miss the requirement to turn the blade around for some operations, or perhaps two marking gauges?
Do I detect another use for a 'throw-away' saw blade in your own gauge? They keep cropping up everywhere, and very useful too.

If I may quote you from sometime in 2005

"I get far more satisfaction from making things that work well than buying things that work well. It's a sense of achievement thing."

I agree entirely, although I am a yorkshireman, and these days amateur.

xy

 

[bugbear]

Do I detect another use for a 'throw-away' saw blade in your own gauge? They keep cropping up everywhere, and very useful too.

Yes, but a less common one in this case - it was an old power hacksaw blade. M2 steel, I think, tremendously hard and wear resistant.

Cutting out the small gauge blade from the "stock" was not trivial.

I have never needed to resharpen it!

BugBear

 

[Derek Cohen (Perth Oz)]

Here's what a ground blade-from-a-drill-bit looks like.

I made a panel gauge and copied the blade from my Colen Clenton cutting gauge.

Flat side of blade faces away from the fence. This also creates a flat face against which the blade is held by a screw.

At the other end of the stem is a pencil gauge ..

And this, itself, makes a great hang hole ...

Regards from Perth

Derek

 

[graween]

Hi.

Derek, which part of the cutting is facing the waste or your gauges ? The round or the flat one ?

Thanks.

 

[Derek Cohen (Perth Oz)]

The rounded back of the blade always faces into the waste (where any wood "dented" by the rounded back will be removed). The flat front of the blade always faces into the "good" wood.

Regards from Perth

Derek

 

[Mr Ed]

Maybe scalpel blades are only for the sharp eyed, thrusting young woodworkers with a delicate touch, but I manage to use them without snapping the blades when marking lines that I can see perfectly well.

In my view the idea of a ready made disposable edge for this type of tool is more attractive than pratting about grinding nails to try and make a cutting edge that will never be as good as one made in a factory.

Each to their own I guess.

Cheers, Ed

 

[woodbloke]

Maybe scalpel blades are only for the sharp eyed, thrusting young woodworkers with a delicate touch, but I manage to use them without snapping the blades when marking lines that I can see perfectly well.


Cheers, Ed

Clearly you haven't yet joined the ranks of the grumpy old f*rts, me included, who require a bi-annual visit to SS :lol: :lol: - Rob

 

[xy mosian]

bugbear, Yes that would be from an old 'donkey' saw perhaps. Cutting a small section from that must have been tricky, were they not fairly brittle? I find it difficult enough cutting a small piece from the modern hard point saw blades, using gilbows that is. I never seem to get a flat section.

Derek, what good looking gauges, and delicate shaping of the points, I don't have any small grinding gear so I will have to mount the point in a pin chuck and rely on the diamond stones used hand held under the magnifying glass.

Ed, sadly I'm in the fuzzy vision brigade these days. I would like to use scalpel blades on any future cuting gauge I might make. I do have some with a nicely curved edge, forgotten the number of course.

xy

 

[David C]

Keeping the bevelled side of a cutting pin like Colen Clenton's, or a cutting gauge like BB's, to the waste, has a significant effect on accuracy.

I show a method of modifiying gauge pins on page 17 of my first book.

David Charlesworth

 

[xy mosian]

At the moment I am making a marking gauge, and have used a bronze Songster pick up needle. First tests show that, without modification, it scratches a line, in softwood with the grain, less than 0.5mm in width. Used across the grain there is some tearing visible, which I would expect. That degree of damage to the surrounding wood, along the grain, is acceptable to me. I am not really bothered by the tearing when used across the grain as I was taught to make such marks with a knife.

I can see that a cutting gauge has more stringent needs in terms of reducing the damage caused to surrounding material. In that the cut line becomes the finished edge and a point such as the one I have at the moment would result in a very small chamfer. Apart from replacing my knife in marking across the grain, tenon shoulders etc. and possible trim cuts in veneer work I cannot immediately think of other common uses for a cutting gauge.

However I have some sort of bug now and may well move on to making a cutting gauge.

David C, Thank you for the reference to gauge pin modifications in your book.

xy

 

[woodbloke]

Keeping the bevelled side of a cutting pin like Colen Clenton's, or a cutting gauge like BB's, to the waste, has a significant effect on accuracy.

I show a method of modifiying gauge pins on page 17 of my first book.

David Charlesworth

David is correct, the point being that two sorts of marking gauges are ideally required in the 'shop, one where the bevelled side faces the stock and the other where the flat side faces the stock. Each is used for a different application - Rob

 

[bugbear]

In my view the idea of a ready made disposable edge for this type of tool is more attractive than pratting about grinding nails to try and make a cutting edge that will never be as good as one made in a factory.

Each to their own I guess.

Indeed. I've never seen a factory edge as good as the ones I can get, quite easily.

BugBear

 

[xy mosian]

Keeping the bevelled side of a cutting pin like Colen Clenton's, or a cutting gauge like BB's, to the waste, has a significant effect on accuracy.

David Charlesworth

Perhaps I'm not seeing straight but would you please explain where the inaccuracies creep in, and to what sort of degree.

Ed, I take your point about edges and cutting gauges. For my use, a marking gauge, I tend to use it both towards and away from me. I think that a scalpel blade would 'dig' in when used backwards, how do you get around this? I notice that your blades are not mounted with one bevel parallel to the face of the stock, do you have any accuracy problems?

xy

 

[bugbear]

Keeping the bevelled side of a cutting pin like Colen Clenton's, or a cutting gauge like BB's, to the waste, has a significant effect on accuracy.

David Charlesworth

Perhaps I'm not seeing straight but would you please explain where the inaccuracies creep in, and to what sort of degree.

If the "marking" face isn't vertical, the mark position can vary with the depth of cut. The maximum error would be the thickness of the blade.

BugBear

 

[xy mosian]

Keeping the bevelled side of a cutting pin like Colen Clenton's, or a cutting gauge like BB's, to the waste, has a significant effect on accuracy.

David Charlesworth

Perhaps I'm not seeing straight but would you please explain where the inaccuracies creep in, and to what sort of degree.

If the "marking" face isn't vertical, the mark position can vary with the depth of cut. The maximum error would be the thickness of the blade.

BugBear

I take that. OK. In the case where the axis of the point is parallel to the stock face, rather than a bevel being parallel to the stock face. The mark on the material surface will be 'wrong' by half the thickness of the scribed, scratched or cut line. So in my case, with a scratched line of less than 0.5mm, 20 thous' of an inch, the error is going to be in the order of 0.25mm, 10 thousanths of an inch. There have been very few occasions when I have needed to work to this sort of accuracy, in wood.

Does anyone regularly work to tighter tolerances than this?

xy

 

[woodbloke]

...a scratched line of less than 0.5mm, 20 thous' of an inch, the error is going to be in the order of 0.25mm, 10 thousanths of an inch. There have been very few occasions when I have needed to work to this sort of accuracy, in wood.

Does anyone regularly work to tighter tolerances than this?

xy

As you say, it's wood...so 'no' :roll: Make the gauge xy, grind the pointy bit (however you want to do it) and see how you get on. If it ain't right, it's cheap enough to make a new one (pin that is) and then use the gauge to make something - Rob

 

[bugbear]

bugbear, Yes that would be from an old 'donkey' saw perhaps. Cutting a small section from that must have been tricky, were they not fairly brittle? I find it difficult enough cutting a small piece from the modern hard point saw blades, using gilbows that is. I never seem to get a flat section.

You would break (or damage) your Gilbows. I used a tile saw (tungsten carbide power coated blade).

Having got a "rough" blade, I ground it to final size/shape.

BugBear