The Band Saw Parts Arrive Sooner Than I Expected

I ordered the replacement parts for my band saw from DeWalt's ServiceNet Monday evening and they were waiting for me when I got home from work this afternoon. The two trunnions came to around $30.00 including shipping, so the damage could certainly have been much more costly. I was was pleased to see that the replacements look a bit sturdier than the originals. I measured the thinnest point of the original casting to be 0.050" where the replacements are closer to 0.075", a 50% increase. While not exactly massive, the new parts should have a better chance of surviving the strains of day to day use.

Much as I would like to install the parts this evening so I can get back to work, I will have to wait until the weekend to complete the repairs. As long as I have the table off, I will be cleaning and lubricating both the upper and lower blade guide assemblies. I will also need to clean and lubricate the thrust bearings, which feel a bit rough. I will be posting at least an initial description of the repairs with photos by Saturday.

Shaker Sconce - Templates/Band Saw Troubles

The Templates

I intended to devote this entire entry to a description of the masonite templates I made for the pieces of my sconce. At least I was able to accomplish that much before my equipment broke down. My thought in making templates was that they would allow me to more easily make multiples of the sconce should the design prove satisfactory.

Using the scale drawing John Shea's Making Authentic Shaker Furniture as my model, I first made full size drawings of the back and side pieces of the project on paper. After refining the curves a bit, I transferred the outlines to 1/4" masonite and cut them out using a narrow blade on the band saw. It was while I was cutting out the templates that I first noticed an ominous wobble in the band saw table.

The Trunnions

Looking under the saw table I could see that there was a problem with the rear trunnion, that is, the part that allows the table to be tilted for bevel cuts. After unscrewing the two locking knobs, I removed the table from the saw and placed it upside down on my bench for inspection. The damage can be seen in the photo at right.

The intact front trunnion can be seen just to the left of the hole in the center of the table. It is semicircular in shape and has a central slot that retains the hold-down bolt, while allowing the table to pivot. The rear trunnion is on the right and has more or less shattered, probably while I was doing the resawing operation I described in my earlier post.

Reading comments about my saw online leads me to believe that I may be one of the last ones on the block to find out that this is a well-known weakness in my machine. I confess that I am disappointed that the manufacturer would employ such a flimsy casting in one of their signature designs. Surely cast iron or steel would have been a better choice than thin cast aluminum in this application. Fortunately, replacement parts are inexpensive and readily available from the manufacturer. I have ordered replacements for both trunnions on the theory that the front one may also be on the verge of breaking and in hopes that the manufacturer will have improved the design of these critical parts.

Before the breakdown, I had entertained thoughts of upgrading the saw to increase its resawing capacity. A riser block is available that would enable me to handle 12" boards rather than the 6" maximum I can now resaw. I also had considered installing a more powerful motor on the saw, but now question whether this machine is really sturdy enough to withstand the strain of either modification. I will defer final judgement on these points until I have installed the replacement parts. In any case, I will be returning to my discussion of safety matters until the new parts arrive.

Shaker Sconce - Resawing

The stock I prepared in my 9/22 entry is now perfectly flat and square but roughly twice the thickness needed for my project. I could thin it down using the surface planer, but that would mean turning half of my beautiful walnut plank into useless shavings. The preferred approach involves slicing the plank in half using the band saw, a process known as resawing. My plank is 7/8" thick. Resawing will yield two planks a bit under 7/16" each, allowing for the amount of wood lost to the saw kerf.

Resaw Setup

The photo at right shows my band saw set up for resawing. The saw is equipped with an an aftermarket Kreg fence, shown in blue in the photo. The vertical extension attached the middle of the fence is a point-contact resaw attachment. Unlike a table saw, which can be counted on to produce straight cuts with a flat fence, the band saw tends to drift to the right or left of the desired line of cut. The face of the resaw attachment takes the form of an arc, which allows me to pivot the workpiece to follow a straight line drawn on its edge.

The blade used here is fairly wide to aid in producing a straight cut, with a coarse and aggressive tooth pattern: 1/2" wide, 3 teeth per inch, hook tooth design. It cuts quickly with relatively little strain on the saw motor.

Resawing

The second photo shows the board being resawn. I used a marking gauge to scribe a line down the center of one edge of the board, then darkened it with pencil to make it easier to see. I then adjusted the fence so the high point of the resaw attachment was spaced half the thickness of the board from the cutting edge of the saw blade. Feeding the board slowly while keeping my eye on the cut, I was able to slice the plank in half with minimal loss of wood.

The photo shows both the curved surface of the resaw attachment and the slightly skewed angle at which I had to feed the wood to achieve a straight cut. Cutting on the band saw is rather sedate compared with the table saw, allowing plenty of time for course corrections. Experience nonetheless helps a great deal in obtaining a clean and accurate resaw. Use of a push stick is required at the end of the cut to avoid finger damage.

Resawn Planks

The final photo shows the cut surfaces of the resawn board. Although the surfaces look pretty rough, the saw marks are not deep and are easily removed with a few passes through the surface planer. See my 9/22 entry for an image of that machine in use. I need both 1/4" and 5/16" stock for my project, both easily produced by the planer, and it looks like I have enough stock here for at least two complete sconces. Once the stock is planed, I can begin laying out the pieces.

To be continued...

Some Thoughts on Safety

This seems like as good a time as any to interject some of my views on the safe use of woodworking machinery. Hearing protection, protective eye wear, and dust collection are givens in using any of the machines shown in my entries. The planer and jointer are relatively safe, requiring mainly that the operator stand out of the way of potential flying wood fragments and, in the case of the jointer, the use of push blocks rather than bare hands to feed the stock. I will cover safety issues for the band saw in my entry on resawing, but it is one of the safest available means of cutting wood. It is the table saw that sends the greatest number of people to the emergency room, both because it is found in so many home and professional shops and due to the dangers inherent in the machine itself.

The Classic Kickback Pattern

Most table saw accidents are the result of kickback. Kickback occurs when the wood being cut makes contact with the back of the blade, that is, the part of the exposed blade furthest from the operator. Because that portion of the blade is moving upward and towards the operator, such contact causes the wood to be lifted up and flung at the operator, often with considerable force. The flying wood can cause serious injuries in itself but, in addition, if the operator's hand is near the blade when kickback occurs, it can be thrown against the moving blade.

Most kickback injuries are hand injuries involving everything from lacerations to partial or full amputations. The photo at right shows the telltale pattern of kickback left on the underside of a piece of wood. Fortunately, I was not injured when this occurred and have since upgraded to a saw with improved safety features. My luck held, but it was a sobering experience.

The cardinal rule in avoiding kickback is never to cut freehand on a table saw. Ripping, or cutting lengthwise, should always be done with the aid of a rip fence, shown in the photo below. The rip fence must be adjusted so it is exactly parallel to the blade. Measurements should be made with an accurate machinist's rule at the front and back of the blade to verify the spacing. Squaring the fence with the front edge of the table is only reliable if you have verified that this edge is truly at right angles with the blade. Though the relationship can be adjusted on most saws, the procedure would easily provide enough material for an entry or two of its own.

T-Square Style Fence

A fence that cannot be relied upon to lock parallel to the blade each time it is moved is extremely dangerous and should be replaced. Fortunately, excellent replacement fences are available from a number of manufacturers. Their cost may exceed that of an inexpensive table saw, but the hand injuries they help prevent would surely be much more costly.

I have a preference for the t-square style of fence pioneered by Biesemeyer and widely copied by others. The fence and its guide rail are extremely rigid and accurate and, since the fence locks only at the front, it is impossible to lock it at an angle. The Biesemeyer knock-off that came with my saw is shown in the adjoining photo.

The rip fence should never be used to guide a crosscut, that is for cutting a piece of wood to length. I will cover crosscutting in my next entry on safety.

To be continued...

Shaker Sconce - Preparing the Stock

Since I purchase my wood directly from a sawmill, it is only roughly finished at best and needs a considerable amount of preparation before I can begin to lay out the actual pieces of my project. Even finished wood from a lumber yard is likely to be too warped, cupped or twisted to be used as-is for furniture or cabinetry. Finishing the lumber myself also allows me to mill it to the exact dimensions I want rather than being stuck with what is commercially available, and it saves me a lot of money.

Face Jointing With the Jointer

I begin by establishing one flat face on the board using the jointer. You can think of the jointer as a giant motorized version of the hand plane. Instead of moving the tool across the wood, as with the plane, the wood is moved across the tool. That would be from right to left in the photo.

The wings on either side of the machine are perfectly flat cast-iron tables. In the center, under the red guard, is a set of cutters rotating at high speed. These are capable of flattening up to a six inch width in one pass, leaving a finished surface. I can control the amount of material taken off in a single pass by raising or lowering the right-hand table.

When planing wood, it is important to keep track of the grain. As with petting a cat, you can run into trouble if you plane wood in the wrong direction! I have drawn in the grain with a sharpie on the edge of the board in the photo to show the proper orientation. If I were to plane the wood so that the grain angled up and to the right, it would tear rather than cut, leaving a rough surface.

The Planer

Having established one flat face on the board, I use the planer to create a second flat face parallel to the first. The planer also has a set of rotating cutters inside, here located above the wood rather than in the bed of the machine. Where I had to push the wood across the jointer by hand, the wood is pulled through the planer under power by means of rubber rollers. I can control the thickness of the finished board by raising or lowering the cutters.

The jointer will create one flat surface on a board but cannot produce a second face parallel to the first. The planer is great at producing parallel surfaces and controlled thicknesses but is not very good at removing warps and twists. Both machines are definitely required.

Edge Jointing With the Jointer

With two flat and parallel surfaces, I move back to the jointer to create one edge at right angles to the faces. The cast iron fence of the jointer, more visible in the first photo of the machine than here, is set at right angles to the bed to guide the wood as I pass it over the cutters. Again, grain direction is very important.

The long bed of the jointer bridges any low spots in the edge so only the high spots are removed by the cutters. I take multiple passes with the jointer, stopping when I hear that the machine is cutting along the entire length of the board. I now have a perfectly flat edge at right angles to the faces of the board.

Ripping With The Table Saw

I use the table saw to produce the final finished edge on the board. I adjust the distance between the blade and the rip fence, the black and white straightedge along the top of the photo, so that a small amount of wood is removed from the entire length of the board. I now have a a board with a perfectly rectangular cross-section.

This description makes the process sound much more complex and time-consuming than it actually is. In real time, it took no more than ten minutes for the entire procedure, not counting the time spent cleaning up afterwards. The finished board may be square, but it is still too thick to be used for this particular project. In the next installment, I will show how I resaw the wood to the proper thickness using the bandsaw.

First Project - Shaker Sconce or Pipe Box

In the Shaker tradition, I will start with something simple and functional. The Shakers were nothing if not great organizers, and this little shelf was designed to hang from one of the rows of wooden pegs that lined the walls of many of their rooms. Present-day smokers will find it serves its original function quite well, while non-smokers may find it useful for the display of small objects or plants.

The design is taken from John G. Shea's Making Authentic Shaker Furniture. While it lacks the sophisticated joinery of more complex designs, it has the functional elegance of the best Shaker pieces. Much of the time and energy consumed in building anything from solid wood is taken up with the preparation of the stock, and the simple design will allow me to concentrate on that aspect of the work while giving me an opportunity to practice my blogging skills on a live audience!

There is no particular variety of hardwood favored by Shaker woodworkers in general. Most used whatever was available in local forests and, in that tradition, I plan to make use of some rough-sawn planks of local walnut that have been gathering dust in my basement shop. In the next installment, I will show how I turn these into finished lumber.

Welcome to My Blog

Welcome to my new woodworking blog! In coming days I plan to make regular posts as I work my way through a series of projects in the Shaker and Arts and Crafts styles. I will begin with objects based on measured drawings of surviving Shaker items taken from Ejner Handberg's Shop Drawings of Shaker Furniture and Woodenware and John G. Shea's Making Authentic Shaker Furniture. Watch here for future developments!