Thread: A nice old Stanley 77 mortise gauge

Very nice, both the original find and your homage to it. I've owned several different mortise gauges over the years, but, once I found a 77, I saw no need for any other. I've got one with the points filed to nothing, and another in good shape. The "filed to nothing" one will serve as backup, in case disaster befalls the good one; I would have to figure out some way to install new points, since there's not enough of the old ones left to get a grip for pulling them out.

Thanks Bill.
The points appear to be a simple press-fit in the brass, but I've never tried to extract one, so not sure how firm the fit is, & if all you've got is an un-grippable stub, it would take some artful dentistry to get it out, that's for sure!

The steel in those points is not hard, and you might be able to drill them out with a centre bit after some very, very careful setting-up. I certainly wouldn't attempt it with an ordinary twist bit, it would be bound to slip off the steel into the brass & make a right mess of it all.

Interesting to ponder what Stanley had in mind when they made the 77 - they were obviously meant to last a while, and you'd think they'd have had some notion that points would need replacing down the track. I started out soldering pins into the brass with my external slider gauges, which is fine for those because you can easily disassemble them for repairs, but it's messy so I soon switched to using Loctite instead, & that's what I used to hold the pins in my clone. That will still present the person who wants to replace them with enough trouble, but at least the regular brew yields under moderate heat.

It was thinking about pins & cutters and their maintenance that led me to dream up my current style for 'ordinary' gauges. I turn a stub on a piece of brass so it can be glued into the end of the beam. The pin or cutter fits through the brass end & is retained with a grub screw: RG cut.jpg

Adjustment/replacement/sharpening is a very simple matter with these...

Cheers,

Digressing a bit here: in my opinion, one of the better vintage single-pin marking gauge designs can be found in the Stanley 64 and 65 series, which trap a pin in a slot by clamping it shut with a little wood screw. I have several, and am contemplating converting one to a cutting gauge by widening the pin slot to accept a narrow knife; but it's another project on The List, and, somehow, the new stuff that goes on The List comes in at high priorities.

Great description Ian, thanks for posting.

Having never owned a mortice gauge to compare with the 77 or your model, can you explain what "locks" the travelling arm? Perhaps the screw thread is sufficiently fine or tight that it won't accidently move?

In order to come across as somewhat informed in my response I did a quick search to try and understand what you were referring to when you said:

The easier way to make a screw-adjusting gauge is to have an external arm that slides in a dovetail channel on the beam.

But alas, despite some online searching I couldn't find anything resembling your description (I did however happen across your very good "Making a marking gauge" article in ARW from 2018).

Lance,

One of the clever parts of the Stanley 77 is that the screw that clamps the fence/body on the arm comes in from the side, pressing against the wooden side pieces of the arm and clamping them against the brass slide, holding it in position. Once that clamping screw is tight, it's hard to move the adjusting screw. For me, it's one of those "well, of course" designs: once you see the cleverness, you (or at least I) wonder why anyone thought there would be any other way to do the job.

Thanks for the explanation Bill. Very clever and elegant solution.

Yep, well-put Bill.
Lance, if you ever have either type of gauge in your hand, you'll very quickly figure out how they work.

I did show some WIP pics of the 77 clone I made for myself here, which might make the construction a bit clearer.

And I posted the making of an early-model screw gauge here.

That was made before I had my little metal lathe, so it's a bit less refined. I was using wooden thumb screws then, too (which work very well, but are actually more fuss to make than brass ones now I have a metal lathe).

This is the very first mortise gauge I made: R_wood original.jpg

The brass slide runs in a dovetail, and you just move it into position with your thumb. I used it for many years, but it's a fiddle to set them - keeping the moveable point in position while you set & tighten the stock can be tricky. You can still buy similar gauges from various makers.

The advantage of having a screw-operated moving point is obvious, it stays put while you set & tighten the stock. Eventually, I figured out it wouldn't be that hard to make a screw-operated gauge with the minimal equipment I had. I cut the dovetail way with a 1/4" router bit, and shaped the brass slide by eye with a file. That may seem a bit rough & ready, but it's surprising how close a fit you can get just eyeballing the angle & sneaking up on the right fit. The end that turns up to be captured by the screw is dovetailed & soldered to the sliding section. The long brass screw (a bit of 3/16" threaded brass that used to be easy to get, but I notice fw hardware stores have it now) goes through a barrel nut set in the beam. The trickiest part is drilling the hole down the beam & the barrel-nut hole accurately, so they intersect with reasonable precision, or the screw won't operate smoothly (or jam & not work at all!). Be prepared for an initial failure, but persistence wins in the end...

These are the bits:Beam assembly.jpg

For my more recent models, I put the thumbscrew on top of the stock, because it's far more convenient there than underneath. Obviously, it was placed there so it bears directly on the slider & locks it in place. But I found if I cut the dovetail so the slider sits a tiny amount proud of the beam, the thumbscrew pushes the beam & brass hard against the surface of he mortise & locks it quite securely. Gidgee MG.jpg

So that's about 30 years worth of my slow evolution in making mortise gauges.

Cheers,