A few naughty readers have been attempting to build collapsible tables and bookcases similar to ones I’ve been constructing for “Campaign Furniture” and have run into some trouble.
Instead of being a wiener-kabob and saying “wait for the book,” here is some basic but critical information about mechanical furniture: In these simple constructions, the pivot points have to be equidistant.
What does that mean? Take a look at the quick-and-dirty sketch above. In these bookcases, the center pivot point is on the outside of the bookcase. The top pivot point it 7-1/4” above that — right below the top shelf. The lower pivot point is 7-1/4” below that right above the lower shelf.
If the upper and lower points are not equidistant from the center, the bookcase will not fold flat. Also good to know: If the distance between the lower and upper pivot points is greater than the length of one of the shelves, the bookcase will not fully collapse. The two center pivot points will run into one another.
I am almost finished building this bookcase and will post a movie later this week.
In your laſt acceptable Letter dated from Weſtminſter the 2d. of Auguſt, I obſerve that you deſire me to turn my Speculations, and to give you my Thoughts upon ſeveral Appearances relating to a Razor; particularly to ſay ſomething concerning its Edge and Sharpneſs, which in a good Razor is ſo fine and ſo nice, that it is ſubject to the leaſt Change and Alteration in the Weather; and particularly that Cold has ſuch an Influence upon it, as to ſpoil and blunt its Edge, inſomuch that it will hardly cut a Hair aſunder.
In anſwer to your ſaid Letter, I muſt acquaint you, Sir, that I ſhave my ſelf, and that my Razor, which I always uſe twice a Week, and which I have had above Thirty Six Years, was never Ground but twice, and yet it cuts very well; but I ſet it ſometimes upon an Oyl-ſtone or Hone, yet not as I obſerve ſome Barbers do, who ſtroke it above Twenty five Times on one ſide, and then again as many on the other; whereas I on the contrary paſs my Razor once only on one ſide, and that very gently with the Edge againſt the Stone, and then on the other ſide in the ſame manner; and ſo continue about ten or twelve Times; after that I paſs the Razor, with the Back of it downwards, upon a Leather prepar’d with Tripoly [which the Silver-ſmiths uſe, to Poliſh or Clean their Plate with.]
When I look upon ſuch a Razor thro’ my Microſcope, I ſtand amazed at the great number of Gaps and Notches that I ſee in the Edge thereof, and wonder how one can ſhave ones ſelf ſo ſoftly therewith; nor does my Razor refuſe to do me Service even in Winter and cold Weather, tho’ I muſt own at ſuch times the Shaving is a little more painful, but that I have hitherto thought, was only occaſion’d by the Hair of the Beard being harder in Winter than Summer, when ’tis cold Weather I always keep my Razor in a Room that has Fire in it. (more…)
The original 19th-century Roorkee chair looks at home on safari. Whereas the mid-century Kaare Klint ‘Safari Chair’ looks right in the home.
As I have been gathering data on original pieces for the forthcoming book “Campaign Furniture,” a critical piece of the puzzle fell into place Saturday when Mark Firley sent me some measurements he took of some original Kaare Klint chairs. Until now, I’ve been relying on auction records, and those measurements were suspect when compared to dimensions I’d struck off of photographs.
Firley, a woodworker and fine American, took good measurements that will help guide the construction of one last chair before the end of the year.
What is surprising – no shocking – is how closely the Klint chairs mimic the original Roorkee of 50 years earlier. They are so similar that it’s almost not fair to call the Safari Chair anything more than a minor evolution from the original.
Here are some details:
The legs of the original were 1-1/2” square and 22-1/2” long. The Klint chair legs are 1-9/16” square and 22” long.
The stretchers of the original were 1” to 1-1/8” in diameter. The Klint chair has stretchers that are 1-1/4” in diameter that are clearly cigar-shaped. I’ve been making my stretchers this shape to add strength in the middle for some time now. So I was pleased to see the Klint chairs were made this way.
The seat height is also similar between the original and the Klint. On the original, the front of the seat was 12” from the floor and the back of the seat is 10-1/2” from the floor. On the Klint, the front stretcher is 12” from the floor and the rear is 9-1/2” from the floor.
The back is virtually identical.
There are some interesting differences. Klint moved the side stretchers down. This gives the chair a sleeker look in my opinion and – engineering-wise – reduces the leverage on the side stretchers.
Klint also removed the handles at the top of the legs, which is probably the most visible difference, but it has little to do with how the chair sits or works.
Firley also supplied some interesting photos of how the seat of the Klint chair works. The underside of the leather seat is lined with a white cloth to prevent the leather from stretching. Modern chairs use a synthetic fabric to stop stretching; I have no clue what Klint used without some analysis.
So if you have been thinking about making some Safari Chairs and thought to yourself: “I can just change the leg turnings a bit and I’ll be almost done,” then you are thinking correctly.
One stick can improve the way you work. Two sticks can change your entire workshop regimen.
This blog entry began months ago when Richard Maguire posted an excellent video called “The Holdfast and the Batten,” which demonstrates how to use a notched batten to secure your work against your planing stop.
It works brilliantly. So brilliantly, in fact, that I started to comb through my old books – both in French and English – for some hint of it. I asked Jeff Burks what he thought. And, most important, I made a notched batten that looks identical to one shown in Albrecht Dürer’s famous “Melancholia I” (1514). This engraving is so famous that it graces the wall of the bathroom at The Woodwright’s Shop.
If you start looking for this notched stick in the historical record, you will begin to see it everywhere. It has different shapes at the ends – ogees, coves, bootjack, etc. Many of these sticks have holes bored in them as well. They appear in workshop drawings, engravings about architecture and geometry, and in images of libraries.
It is obvious that the stick is a straightedge, called a “reglet” in France and England – used to lay things out or to follow a line of text in a book. But why the shaped ends?
Here’s my guess: To differentiate it from sticks that were mere offcuts, scrap or project parts.
And the holes? Peter Follansbee thinks they are for hanging the reglet on the wall. Two holes ensure you are always going to be able to hang the thing without flipping it end for end. I think that’s an excellent guess.
Several weeks ago I made a reglet that looks like the one shown in Melancholia I, and I hung it on the wall above my bench. The bench I use everyday is quite primitive. No tail vise. No dog holes. My leg vise lacks a parallel guide and a garter. It is a lot like a workbench from the 16th, 17th or 18th centuries.
The ‘Dürer Stick’ (as I call it) has been a constant companion during the last two projects. It has been a straightedge, and it also has held my work in place as I traversed it or planed it with the grain. I have ogee ends on my stick, and they work just as well at securing the work as the straight taper that Maguire shows.
Also, the holes in the stick? I used those to nail the stick to the bench to act as a fence while cutting 16 dados today. Again, it worked brilliantly.
Before you jump up my butt about this, know that I am wearing two pairs of flannel-lined pants. Also, I ask you to do this one thing before criticizing: Make a stick. Use it. If you can’t make the stick, you probably shouldn’t be commenting on a woodworking blog anyway.
Was that bitchy? Sorry.
Oh, and what did I mean about how two sticks could “change your entire workshop regimen?” More on the second stick later. This second stick is a mind-blower.
The upper part of this figure will ſhew two ſorts of Graving-tools, the one formed ſquare, the other lozeng: the ſquare Graver makes a broad and ſhallow ſtroak, or hatch; and the lozeng makes a deep and narrower ſtroke. The uſe of the ſquare Graver is to make the largeſt ſtrokes, and the uſe of the other is to make the ſtrokes more delicate and lively. But I preferre a Graver made of an indifferent ſize betwixt both theſe two; which will make your ſtrokes, or hatches, ſhow with more life and vigour; and yet with ſufficient force, according as you ſhall manage it in your working: The forms of which will appear in the I. and II. figures.
The III. figure ſhews you how to whet the two ſides of your Graver, which is to be done in this manner following; you muſt have a very good oyl-ſtone ſmooth and flat, and having powred a little Sallad oyl thereupon, take the Graver, and laying one ſide of it (that which you intend ſhall cut the copper) flat upon the ſtone, whet that ſide very flat and even; and to that purpoſe have an eſpecial care to carry your hand ſtedfaſt, and with equall ſtrength, placing your forefinger very firm upon the oppoſite ſide of your Graver; to the end that you may guide it with the more exactneſſ: then turn the very next ſide of your Graver, and whet that in the like manner, as you did the other; ſo that there may be a very ſharp edge for the ſpace of an inch or better; then turning uppermoſt that edge which you have ſo whetted, and ſetting the end of your Graver obliquely upon the ſtone, carry your hand exactly even, to the end that it may be whetted very flat and ſloping, in the form of a lozeng, making to the edge a ſharp point, as the figure IIII. ſhews you.
It is very neceſſary that you take great care in the exact whetting of your Graver; for it is impoſſible that you ſhould ever work with that neatneſſe and curioſity as you deſire, if your Graver be not very good, and rightly whetted.
I cannot demonſtrate it ſo plain and fully by figures, and diſcourſe, as I would: if you have acquaintance with an Artiſt in this way, you may eaſily underſtand it in a ſhort time.
If the upper and lower points are not equidistant from the center, the bookcase will not fold flat. Also good to know: If the distance between the lower and upper pivot points is greater than the length of one of the shelves, the bookcase will not fully collapse. The two center pivot points will run into one another.
