Marking Gauge

I made this marking gauge a number of years ago after reading an article in Fine Woodworking.
OLYMPUS DIGITAL CAMERA
While it is my favorite (I also have pin and wheel gauges), the wedge is a real annoyance – it works too well and makes it a royal pain to adjust (I do *NOT* like hitting my tools with a hammer). But I couldn’t think of any way to make it better so I lived with it. Then I read Christopher Schwarz blog entry on the Lie-Nielsen panel Gauge and “oh, what a nice simple solution”. Which is to use a screw to press the triangular bream into a groove, thus locking it straight. The beam can be a sloppy fit because it is the bottom of the beam and groove that matter. Loosen the screw and the beam moves easily. Plus, the ability to use a pencil is great. Looks perfect, but at $85, I’m not going to buy one when I can spend $250 of my time making one. Plus, I think I can get better ergonomics. So I poked around in the scrap piles (yes, plural) and came up with a chunk of Claro Walnut, air dried for the last 30+ years, a stick of maple (off cuts from bed slats) and a plastic screw that was used to hold a toilet seat to the bowel (now, aren’t you glad you asked?). Machine screws in hard wood work great, especially the ones with coarse threads, no need to use a brass insert (which I find to be a pain to install), unless you don’t many threads to play with.

The first order of business was to figure out where to put the beam. I put the bottom of the beam about 1” above the bottom of the gauge. which I think is minimum (use one and you’ll see why, especially with the pencil). Since I’m going to wrap my fingers around the beam, I need to shape the body to know where my hands will be so I can place the beam. Took a guess at the shape, using the old gauge as a template, scrawled some lines and used the bandsaw to make the first cuts.
OLYMPUS DIGITAL CAMERA         OLYMPUS DIGITAL CAMERA
You can see the line where I want my palm to move forward. After moving the maple stick around, I marked the placement on the body (the beam will be about 3/4” square). A centerline is drawn across the top for the screw location. Speaking of screws, might as well add that now.
OLYMPUS DIGITAL CAMERA
3/8” x 16 tpi (NC, National Corse). Next, cut the mortise. Now, normal people would use a mortise machine (I don’t have one) or chop them. Not me, I have a milling machine (think giant slow speed plunge router). If I mount the body at 45 degrees, I can move the table in straight lines to cut the angled walls of the mortise.
OLYMPUS DIGITAL CAMERA
The smallest diameter end mill I have that will cut the full depth is 3/8” so that is what the chamfer is going to be. With the mill, I have a very good idea the mortise is going to be square to the body. After playing etch-a-sketch (moving knobs) for a while, I get
OLYMPUS DIGITAL CAMERA
 OLYMPUS DIGITAL CAMERA
And it is square (enough, the beam isn’t).

The hard work is done, now the fun part – shaping. Use a rasp define the shape and make it comfortable, then a metal file to remove the rasp marks, then cloth to remove those marks. I was going for a infill plane look but would up with a whale
OLYMPUS DIGITAL CAMERA
Turpentine use used to get an idea what the color would be like. This is the front of the gauge.
Got the pencil installed, a N sized drill (0.302″) works well. The Wikipedia has a pencil article, which states a #2 pencil is 1/4″ inch across the flats (mine are just over). That’s why the diameter is odd ball. Extra credit: what is the diameter across the points of a hexagon if diameter across the flats is 0.25? My envolope says 0.25/sin(60) = 0.29.

Next I need to make a knife and figure out how to mount it (hollow so I can put a screw through it to hold it in place?), that screw is major ugly, gotta replace it (wood?), brass rub strips?, the shape is really heavy looking, I’d like to “thin” it out. I think it will work well, it is really comfortable, the palm rest is asymmetrical and the beam is rounded so my fingers curl around it nicely.

Advertisements
This entry was posted in Marking Gauge. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s