To develop the curves in the various brackets – here the support for the back fence on the lid of a desk – I followed the ancient practice of melding arcs of a circle along a straight line.
I begin by making a few concept sketches to get an intuitive feel for the curve I would like to see transition the horizontal lid surface to the vertical back fence. I’m going to go with the shape in the first drawing.
From the sketch, it reveals that the overall form suits that of a 1:2 rectangle. (An octave, by the way – but that’s another story). Next, I divide the horizontal length into four equal segments. The first of these segments defines the flat at the top of the curve. I then draw a baseline for the sine curve from this segment point to the lower right hand corner, then divide that baseline into three equal segments.
To find the focal point of the arcs – which will each be one-sixth of a circle’s circumference – I set the dividers to the length of the segment (which is the chord of the arc) and swing out intersections to locate the focal point of the arc. Next, without changing the span of the dividers (because the chord equals the radius for sixth sector arcs as you may remember from Mr. Hammersmacker’s seventh grade geometry class), I swing the arc from the focal point to each segment point. The transition between the two arcs is seamless – proven to be so because a line connecting the two focal points will pass through the arc’s transition point.
Many woodworkers avoid chairmaking for the joinery, the angles, the special tools required or the materials (green, rived stock?). And when it comes to designing a chair, even experienced woodworkers are hesitant to give it a shot because they are afraid they will produce a buttocks-torture device instead of a comfortable chair.
Producing a comfortable chair is the combination of many factors, but all of them are easily controllable. In my short 13 years as an amateur chairmaker and designer, here are some of the design details that I think are overlooked.
The Saddle Many first-time chairmakers carve the seat so deep you could bake a Bundt cake in it. I’ve seen saddles that are 1” deep and so dramatically shaped that they would look at home on a Klingon battle cruiser.
A little saddling (3/8” or so) is nice and it makes the seat appear to flow. But you can get away with little or no saddling and make a perfectly comfortable chair.
The trick – in my experience – is to design the chair so the front edge of the seat doesn’t bite into the sitter’s thighs. You can do this several ways.
No. 1: Shorten the legs a bit so the sitter’s feet rest flat on the floor and their thighs are just slightly above the front edge of the seat. Many shorter people hate factory chairs because the front edge of the seat restricts the blood flow after a few minutes.
Just like with a table, it’s easy to make it too high. But making it a little lower than typical has zero downsides.
No. 2: Take a jack plane and round off the front edge of the seat. You can also do this with a spokeshave – hollowing out two areas for the thighs. This five-minute operation creates the illusion of a saddle and increases the comfort.
The Back Legs The least comfortable chairs I’ve sat in had a seat that was parallel to the floor. It makes the sitter feel like she is being pitched forward.
I like to have the seat drop 1” (at least) from the front edge of the seat to the back edge. I achieve this by cutting the back legs shorter. Cutting the back legs also has the benefit of angling the back of the chair backward, increasing the comfort.
Don’t over-do it. After removing 1-1/2”, it will start to feel weird. A good way to experiment with this is to prop up the front legs on a 1”-thick scrap and sit in the chair.
The Angle & Height of the Back The backrest doesn’t have to be bored at a reclining angle. You can bore the backrest at 90° and use the fact that the back legs are shorter to make the chair comfortable. However, I do like to recline the back a few degrees back (once you get into chairmaking you’ll find that all the angles are as easy as 90°).
What I have found to be quite critical is the height of the crest rail or backrest. In general, lower seems to be better. Once you put something above the shoulder blades, the lumbar seems to suffer.
You can design a chair that has a high backrest, but I think it’s best to also have something below as well for the lumbar (think Jennie Alexander’s chair).
About the Chair Above Roy Underhill made the chair in the photo at the top of this entry. It’s a reproduction of a chair we both saw at Stratford-upon-Avon last summer. To the eye, it looks uncomfortable. The seat is flat. The arms and seat height are lower than a typical modern chair. And the area created by the arms seems like a tight fit (it is for large people).
But the chair is remarkably comfortable. And, if you watch the current season of “The Woodwright’s Shop,” you’ll see how it’s dirt simple to build.
Good morning! Another weekend over and another busy week is upon us. No matter how crazy life is, make sure to take some time to read the forum and see what your fellow woodworkers are up to. Remember, if you have a question about our products, procedures in our books or anything related to Lost Art Press, the fastest way to get an answer is our forum. Check it out here.
No. 7 Adjustment Issues Kendall took apart his Lie-Nielsen No. 7. to sharpen the blade but now that he is putting it back together he cannot get the blade to adjust below the sole. He is looking for any help on what he may be doing wrong. Let’s see if we can prevent him from having to make a call into Lie-Nielsen. Help him here.
Handworks 2017 Does anyone who has attended Handworks have a recommendation for a place to stay? Steve is ready to get his plans together and is looking for input.
Spare Bedroom Workshop Mark and his girlfriend have found a house that they love and want to buy but there is no garage or basement to use as a workshop. Mark is looking for feedback from anyone who has used a spare bedroom as a shop before. Did it work out? How was the noise? Was dust all over the house?
Crucible Dividers Jason likes the pictures of the Crucible dividers but wants to get to the point and find out how they work. If you have a pair, let him know what you think.
Hot Hide Glue Gelling Quickly Josh has had success with hot hide glue on small pieces but has had no success with it when trying to glue up a panel. Every time he finds he is unable to close the joint. He is wondering if anyone would be able to help with why this is occurring.
Staked Chair Travis has made a pair of staked chairs from “The Anarchist’s Design Book” and they turned out great. (Photo at top and to right.) The beveled edges are a great touch!
For the most part, facsimile editions of historical books don’t do much for me. The printing is muddy. The paper is a measly notch above groundwood (aka newsprint). And the binding is weak. The cover, however, always looks nice so as to trick you into buying the poor manufacturing job within.
If you’ve ever bought a facsimile of Thomas Chippendale’s famous book, then you know what I’m talking about. Some companies do a good job with facsimiles; most do not.
So when we decided to reprint the “Stanley Catalogue No. 34,” we wanted to reproduce the look and feel of the original and make some manufacturing improvements, such as a sewn binding, to ensure our version could outlast floods, dogs and babies.
Our first shipment of “Stanley Catalogue No. 34” arrived smack dab in the middle of Woodworking in America, and I haven’t had much time to look at it. (I had one in the car that I was examining at stoplights; that’s how nuts it has been here.)
So I’m happy to report that this book has exceeded every expectation I had for it. The prepress people managed to make plates that mimicked the original’s crisp drawings and text. The black are black. The screens are real screens – not some moire mess.
Our warehouse is getting an assembly line together during the next week to ship out all the pre-publication orders. So if you placed an order for one, it will be on its way soon.
“Stanley Catalogue No. 34” is $25, which includes shipping in the United States and Canada. Many of our retailers have decided to carry the book, including Lee Valley Tools, Lie-Nielsen Toolworks, Henry Eckert in Australia, Tools for Working Wood in Brooklyn and Classic Hand Tools in the UK. Check out our international ordering page for links.
You can now visit crucibletool.com, and read up on our holdfasts, our new dividers and why we started this company. I’ll be adding a lot more blog entries in the coming week, including:
How to retrofit a benchtop to use 1”-diameter holdfast holes.
How to carefully ream holdfast holes for a sweet fit with the tool’s shaft.
A tour of Chris Erhart Foundry, where our holdfasts are poured.
An update on the next batch of dividers.
Note that we are not taking backorders for the dividers. To prevent us from getting into a bad situation that plagues many young businesses, we have decided to sell only what we have in stock. No backorders. No waiting lists.
When we have stock, we will announce in advance when the dividers will go up on the site so everyone has a fair shot. And we think we’ll soon have enough to keep them in continuous stock.
So when we decided to reprint the “