Cutting gauge from a pig's ear.

[Derek Cohen]

About a year ago I posted a couple of cutting gauges that were based on the Kinshiro cutting mortice gauge: http://www.inthewoodshop.com/ShopMadeTools/CuttingGauges.html


http://www.inthewoodshop.com/ShopMadeTools/CuttingGauges_html_m6adcaa26.jpg


These cutting gauges were the Western version - a pseudo Japanese cutting gauge - as the knife was made from a HSS drill rather than a bent steel blade. This has a significant disadvantage, in that the cutting edge lies in board and, as a result, visibility is reduced. There is another advantage to the bent steel blade, which I shall demonstrate later.


Note that the Kinshiro is a mortice gauge but may be used as a single knife gauge for tenons and dovetails. There are a number of other uses for this type of gauge, such as slicing banding.


The Kinshiro are no longer available. I got to thinking that I could upgrade a cheap version of a Kinshiro-type gauge into a decent alternative to be used specifically as a single cutter, ala dovetail gauge.


Tools from Japan sell the Large Ryuma for $17. This comes with 2 blades for mortices ...


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG1_zps0cbcf5d8.jpg


The bones are decent but need work. The body is about 3/4 the thickness of the Kinshiro. The blades are a little rough but have potential. The wing nut is a disaster - too difficult to adjust with one hand. And how to adjust one blade with one hand?


Here is the completed modification (a stage beyond a recent post on these gauges) ..


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG2_zps06c8ddeb.jpg


Alongside the Kinshiro ...


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG3_zps645bbfb3.jpg


There is more registration depth than in the original ..


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG4_zps70819cec.jpg


In addition to the lamination at the front (I used Jarrah - what else?!), another lamination was added to the blade carrier to replace one blade and raise the remaining blade flush with the top.


The back of the blade shaft was serrated to create resistance and enable it to be pushed with the thumb.


A brass knurled knob was added.


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG5_zps58b63f59.jpg


The blades need to be ground and polished on both sides. Two blades enable one to score lines in either direction, that is, with the knife's bevel either towards or from the gauge. The finished blades are on the right side ..


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG6_zps14e638ce.jpg


What I particularly like about this style of knife is that setting the gauge for dovetailing is so much easier. To set for an depth that is exactly that of one side, simply place the gauge on top of the board, and drop the knife to the table. Tighten. Done.


http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Cutting%20Gauge%202/CG7_zps6756d0bf.jpg




Regards from Perth


Derek

[Paul Saffold]

Very nice Derek,
That's a good idea to replace a blade with a spacer and have your choice of bevel in or bevel out plus the ability to use both blades as intended as a mortice gauge. The Jarrah certainly dresses it up. Another class act from down under.
Paul

[lowell holmes]

Well,

I ordered one.

We will see how this goes.



I've never considered a pigs ear for a mortice gage before. :)

[Mike Allen1010]

Derek,

As usual, a great idea, excellent execution with well-thought-out design details! I am definitely going to do this based on your suggestion -- I hope we don't exhaust Stu's inventory to quickly!

BTW, I always enjoy your tool post- thanks for sharing.

All the best, Mike

[lowell holmes]

Well,

My pig's ear errr. . . . mortice gage arrived today.

I'll have to give it the Derek treatment. .

[lowell holmes]

Derek,

My Ryuma arrived yesterday.

To reiterate your changes to the gage, my understanding is that you did the following:

1. Added wood to the face of the gage, the thickness being 1/4 of the exisiting thickness.
2. Put a knurled brass set bolt on the blade lock.
3. Added a spacer in the blade holder to raise the cutting blade. The thickness of the spacer being the same as one of the blades.
You use the gage as a marking and/or a cutting gage.
4. Dressed the finish on the blades and honed the cutting edges.

Thanks, :)

[Derek Cohen]

Hi Lowell

Spot on. Looking forward to seeing yours!

Regards from Perth

Derek