An evolution of mortising gauges

**IanW** · 3rd July 2013, 09:22 PM

I was helping another addicted toolmaker with some parts to make a mortiseing gauge a few days ago, so while I was at it, I started on one I’d promised for a friend, an embarrassingly long time ago. While a mortising gauge is a bit more involved than a gauge with a single pin or cutter, you can still make simple versions with very basic tools.
My first attempt at a mortise gauge, and probably the 3rd or 4th gauge I ever made was this one in (Sth American)Rosewood:

R_wood original.jpg

I cut the dovetailed groove for the sliding point with a bit I made by grinding the end of a ¼” steel bit. The brass inlay & sliding piece were hacksawed from 1/8th brass plate and filed to fit, which I found easier to do than I expected. While this gauge did the job, anyone who has used this style will know they are a beast of a thing to set. Holding the points setting while you get the stock adjusted can take several attempts & a few expletives before you get it right!
So after thinking about it for a little while (about 20 years :roll) I eventually made a gauge with a screw control for the moving point. That was based on an old Stanley that I got my hands on briefly, but similar gauges were made by numerous other manufacturers. The guts of these gauges is a simple screw mechanism that moves the sliding piece back & forth:

Beam parts.jpg

You can make all the necessary parts quite easily with simple gear. The end-piecewhich is at a right-angle to the slider is attached with a double-dovetail, which is not difficult to do, but simply silver-soldering them together should work. The nut & thumb screw can be made on a wood lathe from lengths of brass rod, but of course it’s easier if you have access to a metal lathe.
What you gain is a gauge that is much easier to set, but they have one small ‘weakness’. As you open the pins, the thumbscrew & slider project further from the beam, & when set for a wide mortise, they are sticking out quite a long way:

Beam assembly.jpg

This makes them vulnerable if dropped, & in fact you can see in this pic of a couple of oldies that the slider has been bent on the gauge on the right:

Old Stanleys.jpg

Stanley’s answer to that problem was the #77 gauge, in which an internal slider carries the moveable pin, & the thumb-nut stays in the same relative position as you widen the gap between the pins. This keeps it compact & less likely to be damaged by accidents. When the stock is locked in position, it clamps the slider very firmly, so all round it is a very neat & effective design The minute I saw one of these gauges, I knew I had to try making one, but it had to wait a few years til I had the time & gear to do it. Eventually it got done.

While I’m very happy with my “77.01”, it is more complex to make than the extending slider style, & needs a fair amount of precision to work well:

77 clone bits.jpg

So if you are contemplating making a mortising gauge, it is probably not the one for your first attempt. Better to start with the simple finger-operated type, or try the basic screw system if you can make the nut to capture the slider. The last incarnation has the stock rotated so the lock screw is on top instead of underneath, which makes setting more convenient. By having the brass slider a tiny bit proud of the wood, it locks just as securely as having the screw bear directly on it. I have also added more brass ‘bling’ than on the original (only because I can, it works no better than its predecessor):

Gidgee MG.jpg

And so here is my ‘evolution’ in mortise gauge-making, from the simplest on the left to the most elaborate on the right. Any one of them is capable of doing the job, of course.

All gauges1.jpg All gauges2.jpg

Cheers,

**Berlin** · 25th July 2013, 10:44 AM

I only just saw this thread Ian! I would already have commented and owned up as the tool addict that got his mits on the lovely brass bits from the Wilkut lathe.

I actually finished my gauge 2 days after I dropped 'round but the stint up North got in the way of putting some wax on and taking a photo.

I'm really happy with the result. Other than just taking my time it was all fairly strait-forward. the double DT on the traveller was a little tricky but even that I got on the second attempt.

I have a ways to go to get to your level of finish but I can see why you've got gauges coming out of your ears, they're very satisfying to make.

I have almost finished the second gauge too and will post it as soon as get the pin sorted.

Cheers
Matt

ImageUploadedByTapatalk1374708415.250219.jpg ImageUploadedByTapatalk1374708558.927402.jpg ImageUploadedByTapatalk1374708602.398193.jpg

**IanW** · 25th July 2013, 04:05 PM

Yep, I can see the family resemblance, definitely a grandchild....

But a question, is the wear strip on the wrong side, or did you just assemble it that way for the photo?

Oh Yez, making any tools can lead to addictions, but these little blighters can suck you right in! They require only the smallest bits of wood, so I end up saving miniscule scraps for jobs like this, & now I have my metal lathe, even tinier bits of brass get saved for some of the metal parts!

Cheers,

**FenceFurniture** · 25th July 2013, 05:53 PM

Originally Posted by Berlin

I only just saw this thread Ian!

Me too Matt!

Good work, both of you. Great to see Ian's influence rubbing off in the most tangible way.

**Berlin** · 25th July 2013, 05:55 PM

Whoops, just assembled upside down for the photo fortunately and not made that way! Actually, after you pointed it out, I made a new stock with the beam more resolutely off-centre than I had it at first.

The next gague has fallen a little further from the tree in terms of aesthetics but still has a bit of the old dna

I'm not sure when I'll have it finished though. I'm laid out flat in hospital after being bitten by a Komodo Dragon... Ok, a cat. It's alright, you can laugh. It's not a very butch reason be off work.

**IanW** · 25th July 2013, 09:48 PM

Originally Posted by Berlin

....... I'm laid out flat in hospital after being bitten by a Komodo Dragon... Ok, a cat. It's alright, you can laugh. It's not a very butch reason be off work.

Actually, cat bites can be pretty serious business, Matt. They can carry a couple of very nasty organisms in their mouths, & I've seen a couple of colleagues come near to losing limbs over cat bites, so do listen to your doctors in this instance (& think about replacing the cat if it makes a habit of attacking you..

).

Cheers,

**FenceFurniture** · 25th July 2013, 10:05 PM

Originally Posted by IanW

(& think about replacing the cat if it makes a habit of attacking you..

).

Yeah, with something a bit more mild mannered like Nursie-Girl

**Berlin** · 26th July 2013, 09:13 AM

It's not even my cat! The last item on the list of things to do at the place we're house sitting was 'worm the cat'. He's sweet as pie normally but you'd think I was coming for his balls the way he panicked

.

I'm feeling more or less normal today.

Ian, I've asked them to let me know what they find in the blood cultures. You can tell me if it's anything worth mounting on a tiny little trophy board.

Brett, I don't know what you're into but I've never thought of trying to worm a nurse

. I can't imagine it's easy.. better oral hygiene maybe.

Matt

[edit] no cultures taken. I'll never know who my visitors were.

**code4pay** · 26th July 2013, 09:26 AM

Originally Posted by IanW

The nut & thumb screw can be made on a wood lathe from lengths of brass rod

Are there instructions for doing this?
Thanks
Mike.

**FenceFurniture** · 26th July 2013, 09:29 AM

Originally Posted by Berlin

I'm feeling more or less normal today.

I've heard about this. What's it like? Might have to try it one day....

**IanW** · 27th July 2013, 07:49 PM

Originally Posted by code4pay

Are there instructions for doing this?
Thanks
Mike.

Mike, I just made it up as I went along, & managed to make a few things from brass over the years. I used a round-nosed cutting tool made from an old (very heavy) file, but ordinary tool steel can handle brass and aluminium. Keep the rest close to the work & take light cuts. If that scares you too much, a coarse file will remove lots of metal quickly. Clean up with smooth-cut files & emery paper.

Just did a quick google & turned up this:

And this:

- which may be more helpful than my trying to explain it.....

Cheers,

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