I pulled this from "over there" and made some minor updates.
Figured it fits in with the current blog series title.


Some initial thoughts
I've had reasonable success selling Arts & Crafts style lamps and currently I am making another set.

One of the challenges with these lamps is building the shade. There are a number of angles and dimension to consider and any error in one of these parameters will alter the parameters of every other piece.

When making an A&C style lamp, you build the lamp body and you build the shade. Each is about the same amount of effort.
I thought a blog post would be a good way for me to collect my ideas together for a method I worked up and to possibly encourage others to build these shades.

The Magazines

Several magazines have had articles giving instructions for building an A&C lamp with details for the shade. I've read both these articles (one is available online as a pdf, hint: search for "wood magazine 148 2003.pdf" ) and have not been totally thrilled with the techniques they use. On the other hand, I would never have given the subject more critical though had I not read the articles 8^)

My goal now is to further refine my approach to more efficiently make multiple copies of these unique lap shades.

Fixtures and Jigs

As with most any manufactured item, using fixtures and jigs is a great way to gain quality, consistency, and efficiency. These shades need help in all three areas to keep my sanity intact. I think I have found a way to "jigify" the process such that everything goes easier.

The Design

First thing needed is a design.
I like the general shade dimensions used in the articles and have adapted my setup to accommodate production. Here is a simple drawing of the panel frame showing the key part dimensions.

Note that the dotted lines are where the pieces are eventually trimmed flush.

A good general mathematical description to determine the lengths and angles for an arbitrary shade of multiple sides can be found here (sorry, link no longer works)

A more lamp oriented description (with figures!) is here

Again it's not the absolute numbers that matter, it's being able to consistently cut all pieces close to those numbers. My goal is to find methods that allow errors in cutting to be reduced or eliminated in each step and offer chances to "reset" things if some errors creep in during the build. The desired result is ending up with a shade that has tight joints and crisp edges.

The Tools
Miter gauge

As with any project, good tools help make things easier.
The primary tool needed is a good miter gauge. The ability to set to an exact angle is not as important as having a non-sloppy fit into the miter slot and the ability to somehow set the gauge up to the exact same angle repeatedly. 
I use an Incra 1000 miter gauge that can easily be repeatably set to any angle.
If you just have a stock gauge, make it so you can add wider fence and have a scrap of plywood cut close to the proper angle. You can use this plywood to set the miter angle consistently for either side of the blade, consistency is key.

Table saw

You need a saw that has good arbor bearings and sharp saw blades. Basically the blade should cut straight and true and not wobble or deflect during cuts. The fence should be set parallel to the blade and not move or deflect during cuts.

Steel rule

I use a 24" etched steel ruler to set my miter gauge stop to the plan dimensions. It is graduated down to 32nds of an inch and the etching allows me to clearly align the mark with the saw blade tooth. During this project, I found that even despite careful stop setup, I had to adapt the dimensions as I progressed. My parts were all exactly the same lengths, but never exactly the planed length. This did not matter since I could adapt without any consequences.

Next part will begin with the wood preparation and cutting a pile of parts.