05 November 2012

Marking Gauges

Sometimes you get jobs in the 'shop that niggle...this was one of them.  For several years I've been using a fairly simple Japanese marking gauge  from Classic Hand Tools, alas no longer available.  The long stock and wide stem, coupled with true cutting knife blade almost guarantees to make them foolproof, but in addition, the blade has around a 10deg 'toe-in' which in use draws the stock tight against the workpiece, so none of those dreaded 'tram lines'

As I had a number of oddly assorted gauges apart from this one, I reckoned a couple of new ones, using the original as a pattern might be a 'good thing'.

I started by making the bolts and silver soldered an oddment of steel into a slot in the ends...

















...and then came the preparation of the material (English Oak in this case and not the original Japanese White Oak) followed by some careful routing of the slots...a 12mm one for the stem and a 4mm slot across the grain to contain the 6mm captive square nut.

















A little shaping was the next little job, using the original stock as a template and then a 7mm hole was drilled down the grain for the bolt.  The next bit proved the hardest...how the hell to you make a narrow slot across the grain for the blade?

Needle file?...nope, too wide.  Warding file?...same again, too wide. You can see my abortive attempts on the trial piece of oak on the left.  Eventually, after a bit of head scratching...

















...I ground down a hacksaw blade and used it to make the tapered (through the thickness) slot, the 'toe-in' can clearly be seen in the pic.  I used a couple of bits of the same blade to make the tapered blades and ground them to profile using the Tormek and a high speed grinder, so that they just tapped in with around 2mm of the cutter proud on the underside.

















The backs of the stems were also rounded over to fit the routed slot in the stem.

The final bit of metalwork were two 'U' shaped pressure brackets made from...

















...a couple of oddments of mild steel.  With a few passes of a smoother and the sharp corners knocked off with a block plane, the completed gauges sit...

















...very well along side the original Japanese one.

So, if you're in the market for a simple gauge that really does work a treat, spend a few hours knocking up a couple of these, you won't regret it!

2 comments:

Howard in Wales said...

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Nicely done.

I.m not a big fan of Japanese tools as a rule, but this is a very good one.
I believe that Dictum gmbh in Germany (Dick as was) still sell a few variants, both with the screw and with a wedge - you take your pick..


That’s where I bought mine a few years ago, but you’ve planted the seed and I should make a couple more.

No doubt about it, they are very useful and it pays to keep a couple at different settings.

Great for scribing tenon shoulders from the end of the board and you’re absolutely spot-on – they don’t deviate from the line and give a clean cut.

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Andy said...

Nice job Rob. Please can you bring them along to the nice Japanese tool meet I wood like to have a good look. They look great to me.
Cheers
Andy Ryalls