Since this blog seems to be transitioning from all-workbenches-all-the-time to all-stools-all-the-time, I thought I’d pass along something I came across recently. The Batonga people, of present-day Zimbabwe and Zambia, have traditionally carved stools out of single log sections. The stools range from very simple:
http://outofthisworld.co.za
to much more elaborate:
http://www.michaelbackmanltd.com/
They sometimes incorporate a carrying handle, as the latter image shows.
Designs vary quite a bit, although there are some recurring themes. I do wonder about the long-term viability of a stool whose supports incorporate a sharp, cross-grain right angle:
http://www.safarifusion.com.au/
Then again, the people who carve and use these probably don’t have BMI levels in quite the same range as our own.
If you do a search on “batonga stool” you’ll find quite a few for sale.
Last summer I attended the Lie-Nielsen Open House and intended to publish a photo gallery when I returned home. For various reasons beyond my control that project was shelved. I thought I would finish the project to help fill in for a slow week here on the blog. If you have never attended the open house at Lie-Nielsen I would highly recommend it. Consider making room in your schedule for the next event this July.
The gallery contains 1325 photos from the event and will use ~400MB of bandwidth per viewing. For that reason I would not recommend browsing from a cell phone unless you are connected to WiFi.
I have tested the gallery to work with all manner of desktop computers, tablets and smart phones. A direct link to the photos is available if you would prefer to just download the whole set and view them on your preferred device offline.
This is the first gallery I have posted in a long time. The software and hosting is new. The website is just an empty shell that may have unresolved bugs. If this test goes well I will be adding more galleries from other events when I get time.
I love the smell of ponderosa pine in the morning…. Smells like…vanilla.
–Lt. Col. Bill Kilgore, Apocalypse Now (director’s cut)
We’re going to travel a little further afield today, but first, a correction: Last time, I posted a photo that I claimed was of a tuliptree, but as A Riving Home pointed out in the comments, the photo was actually of a mockernut hickory (Carya tomentosa). What happened was that I had taken photos of both, but at the last minute decided to save the hickory for a later post, and then managed to mix up the photos. Here’s the real tuliptree:
(The description in the previous post still applies.)
In February, the forest begins to show signs of renewed life. The earliest migrant bird, the Eastern Phoebe (Sayornis phoebe), has arrived, and the resident species are singing their hearts out. There’s some color seeping into the grayness of the landscape, and on a warm, rainy night, you might hear a chorus of spring peepers (Pseudacris crucifer). By the end of the month, some of the trees have begun blooming. The most noticeable of these are red maple (Acer rubrum), with its deep red flowers, and silver maple (A. saccharinum) with dull orange flowers. The pinkish flowers of American (Ulmus americana) and slippery (U. rubra) elms quickly give way to pale green flying saucer-shaped seeds.
Some shrubs begin leafing out in February as well, but these are nearly all non-native plants, such as Amur honeysuckle (Lonicera maackii) and autumn olive (Elaeagnus umbellata). The native plants know that there’s still a good chance for a hard frost, so they wait.
We begin in an area of bottomland near the Hocking River here in Athens County, where there are a couple of species that dominate. First, one of the easiest of all trees to identify:
The patchy, ghostly white and gray bark of the American sycamore (Platanus occidentalis) always stands out against the gray backdrop of the winter forest. Close up, the lower portions of the trunk are covered in numerous small, brown scales:
The other dominant bottomland tree in this area is the often huge eastern cottonwood (Populus deltoides):
Its bark is deeply and coarsely furrowed, with the ridges being more or less flat-topped.
Both of these trees can be found further up slope, but it’s always a sign of abundant ground water when they are. In particular, you can find these trees along ravines and exposed layers of porous shale, where the soil is always wet. These layers of shale correspond with coal seams, in this area the Middle Kittanning or “No. 6” coal.
One of the most important trees to a woodworker is black cherry (Prunus serotina):
Further north and at higher elevations, black cherry can be the dominant species in a forest, but around here it’s mainly found as scattered individual trees, usually but not always near water. The bark is dark, brownish-black, and broken up into oval scales that curl up around the edges. Another feature of cherry trees is that they are almost never straight. This is because as the tree grows, the main stem has a pair of terminal buds, rather than just one, and one of the buds “wins,” depending on the lighting conditions. Thus, each year, the tree heads off in a slightly different direction.
We’re going to move up slope now, to some forested land that my wife and I own just over the county line, in Meigs County. A close relative of the eastern cottonwood is bigtooth aspen (P. grandidentata):
The bark is a medium gray, sometimes with a gold sheen, and interrupted by a combination of horizontal ridges and vertical splits. Further north, quaking aspen (P. tremuloides) replaces bigtooth aspen; its bark is similar but whiter.
American beech (Fagus grandifolia) is characterized by smooth, nearly featureless gray bark:
There are several species of hickory in the forests, most of them difficult to tell apart. The aforementioned mockernut hickory is fairly common:
The bark has the sort of criss-crossing X ridge structure that many of trees in the forest have, but in the hickories, these ridges tend to look as if they are strands braided together. This is more apparent in a young tree:
One species of hickory that is not hard to identify is shagbark hickory (C. ovata). Although the braided pattern is obscured, you can still kind of see it if you squint; it tends to be more obvious near the base of the trunk:
Pines are tricky. A big part of that is that people plant a lot of pine trees, and the species that they plant are very often not native to the area, so you never know what you’re looking at. Around here, only one native species of pine, Virginia pine (Pinus virginiana), is common:
It’s characterized by relatively short (about 2″/5 cm) paired needles that are flattened and somewhat crescent-shaped in cross section, and usually twisted.
The other pines that occur in the area all have much longer needles: eastern white pine (P. strobus), pitch pine (P. rigida) and shortleaf pine (P. echinata). It generally takes a combination of characters (number of needles in a bundle, shape and size of the cone, etc.) to distinguish these species.
Ponderosa pine (P. ponderosa), a species of the western half of the United States, really does smell like vanilla, although you have to get your nose right up to the bark to notice it. You won’t find any ponderosa pines growing around here, but you might nevertheless find it at your local home center; the clear pine boards are often cut from that species.
Not everything in the forest is a tree, of course. There is a ground-hugging plant that looks strangely like a conifer of some kind:
And one of its common names is indeed “groundcedar.” In fact, though, it’s not a conifer at all, but rather a member of an ancient lineage of plants, Lycopodiophyta, and not closely related to any of the more typical plants. This one is the fan clubmoss (Lycopodium digitatum).
Sedges (Carex sp.) are a rather overwhelming group of grass-like plants; there are about 2000 species worldwide, and 140 just in Ohio. One of the most common is eastern woodland sedge (C. blanda):
There are many species of ferns in the forest, but these two are the only ones that are likely to remain green in winter:
The marginal woodfern (Dryopteris marginalis), on the left, may die back to the ground in very cold winters, but the Christmas fern (Polystichum acrostichoides), on the right, stays green regardless.
The marginal woodfern can be identified by the fact that the sori (the spore-bearing structures on the undersides of the fronds) are located along the margins of the pinnules:
It’s still a bit early for wildflowers, although I did find the leaves of this eastern waterleaf (Hydrophyllum virginianum) poking through the leaf litter:
The only blooming flower that I found (actually, I think my wife found it) was this non-native purple deadnettle (Lamium purpureum):
In the years since I wrote about and hosted a video on building the knockdown workbench from the collection at Old Salem, N.C., folks have sent me hundreds of photos of the benches they have built. I absolutely love getting these. I am always interested to see the different vise set-ups, materials and alterations different people have done with the design.
I few days ago, Luther Shealy sent some photos of a Moravian work bench he has nearly completed. Shealy is in the U.S. Army stationed in South Korea. He had to leave his Roubo bench behind when he was deployed overseas.
Fortunately the Army base has a morale and welfare shop the servicemen can use, and he decided to build a bench for use while in Korea. He was able to source the pine parts of the bench on location, but the oak part proved to be problem. Undeterred, Shealy had friends back home mail him enough white oak for the short stretchers. He brought the oak vise chop over in his luggage; that must have been interesting trip thru TSA!
I very much admire Shealy’s determination to make this happen in a less-than-ideal situation.
I was flattening some panels by hand the other day (too wide for my machines), and that got me thinking about plane blade camber. If you search online for discussions of blade camber, you’ll find that a great many electrons have been spilled on the topic. One common thread in these discussions is frequent confusion over the fact that a bevel-up blade requires more camber (i.e., the center of the blade needs to protrude further beyond its corners) than a bevel-down blade to have the same effect.
On the one hand, everyone seems comfortable with the notion that as the blade’s bedding angle decreases, the effective radius of curvature of its edge increases. This is easy to see. First, find yourself a thin disk (e.g., a CD or DVD) and hold it up at arm’s length:
When the disc is perpendicular to your line of sight, the apparent radius of its lower edge is equal to its actual radius (2-3/8″ in the case of a CD/DVD). But start tilting it from perpendicular, and the curve flattens; its apparent radius increases:
Tilt even more, and it keeps increasing:
From the point of view of the wood fiber that’s about to have its head chopped off by an oncoming blade, the greater the tilt from vertical, the greater the apparent radius of curvature, and consequently the less the depth of cut at the center of the blade. And since the blade in a bevel-up plane is tilted further from perpendicular, its apparent radius of curvature is larger than that of the bevel-down blade unless we make its actual radius of curvature smaller (i.e., increase its camber). Easy.
On the other hand, we’ve also all seen diagrams of bevel-down vs. bevel-up planes seated on their respective frogs:
The resulting cutting geometries in the two cases are identical. The blade’s cutting edge comprises two intersecting planes, one formed by the back surface, and the other by the bevel. The only difference between the two configurations is that these two planar surfaces switch roles.
This is where I think some people get confused. If the two setups are equivalent, why can’t we measure the blade camber in the same way with both? In truth, we sort of can, but there’s a difference between the bevel in a cambered blade vs. a straight blade. When the camber is small, that difference is also small (and negligible), but with a strongly cambered blade, such as one we might use in a fore or scrub plane, it’s not. With a cambered blade, the bevel is not planar. In fact, the bevel is a section of the surface of a cone:
That’s where the equivalence breaks down, as it’s no longer possible to directly superimpose the cutting geometry of a bevel-up blade onto that of a bevel-down blade. And so we go back to always measuring the camber with respect to the back of the blade.
Anyway, is any of this important? Only to the extent that you get a feel for how the different parameters interact, so that you’ll know how much to camber your blade to achieve a given depth of cut.
I’m avoiding the math here, because it’s been covered before (such as here and here), but I did put together a little online app that lets you plug in some numbers to see how this all works. Here’s a screenshot:
You can find the app here. To use it, enter your bed angle and blade width, and one of the other three values. The app will compute the other two corresponding values for you, dynamically updating the display as you modify the values. The bed angle is in degrees; the other values can be in whatever length units you choose, as long as you’re consistent (inches, millimetres, furlongs, it makes no difference).
Now, I know that someone is going to read this and then get out their micrometer and measure their blade camber to three decimal places, to which I say,
STOP!! PLEASE STEP AWAY FROM THE PLANE!!
The point of the app is intuition, not prescription. The precise value of camber that you end up with is largely irrelevant, as long as you’re in the ballpark.
