Thursday, November 20, 2008

mortiser



Friday, December 30, 2005

Shop-made Bandsaw Table and Fence

under contruction -- updated 01-19-06


This website illustrates how I constructed a combination enlarged table/adjustable fence/sled for my laguna tools 18 inch bandsaw.

(Let me express my appreciation for the assistance given by James Haddock in the early stage of developing this project. Let me add, too, that I take a little pride in reporting that my shop-made bandsaw table and fence came in 17th, from among 550 entries, in the "Solving a Woodworking Problem" contest, conducted by Woodworker's Supply, Summer and Fall, 2005.)


I have owned my bandsaw for 4 years, since June 2001, when I retired. When I purchased it, I also purchased a Robland x31 combination machine. I have been an amateur woodworker for over 40 years, and until 2001, but during that time never owned nor used a bandsaw.

As well, I own a 1970s Delta Unisaw, a 1950s Delta Double-Arm Radial Saw, and recently I purchased a Hitachi 10-inch sliding compound miter saw, with laser light. And I have just rebuilt a 1950s vintage shaper/router (In the near future I'll post a file on the rebuilt shaper/router.)

Nonetheless, one of the most useful tools in my shop, the bandsaw can, like a table saw do most of my cross-cutting and ripping. It really shines, though, in resawing thick/wide stock or slicing off thin veneer, in cutting curves, circles, tenons, and dovetails like a jigsaw, scroll saw and/or tablesaw, in following templates like a router, and, uniquely, in sawing compound curves. Another asset of a larger bandsaw is it's (3hp or greater) more powerful motor.

Where the bandsaw lacks versatility, primarily because of its limited table size, is in ripping and/or resawing larger boards, and in cutting sheet goods. Limited table size (i.e., the bandsaw’s 18" “throat”) also limits its cross-cutting capacity.

I have heard that Europe’s equivalent of osha will not allow stacked dadoes, which means that, for dadoing and rabbetting, European craftsmen greater emphasis falls upon shapers and router tables, with a de-emphasis upon table saws. Take the capacity of dadoing/rabbetting away, a table saw’s other major attributes are cross-cutting and ripping, both tasks that also can be done on the bandsaw. In other words, you can make the case, as did Gary Rogowski, a Portland-based professional woodworker/teacher, in a recent issue of FW, that a bandsaw is a more important first purchase for woodworkers than a table saw. Would US woodworkers widely embrace this claim, at least to the point of making a bandsaw their choice for first purchase over a tablesaw? With enhancements of bandsaws, I believe they would. Already the market is breaking out of the 14-inch syndrome, and amateur woodworkers are, increasingly, purchasing 16-inch or larger bandsaws,

Now it is true that, in comparison with the polished cuts possible with, say, Forrest blades on the table saw, the quality of cuts on the bandsaw come up short. (Clean up of cuts can be done easily with the jointer and/or planer or performax-type sander.) On the other hand, safety considerations, like no kickback, and the narrower width of the kerf, which means less waste sawdust, give bandsaws specific advantages. But all of these issues are choices each woodworker makes, according to his particular likes and needs.

Taken together, many of the things mentioned above persuaded me that without enlarging the table of my bandsaw, its capacity for becoming a more central tool in the shop was limited. With that in mind, I began experimenting a little, and with experience, have arrived at the model for an improved table/fence/sled combo that you see in photos below. Improvements and/or changes are made as needed, though.

My table/fence cuts accurately, the set-up is quickly adjusted, and using the graphing makes everything easy to read, especially for repetitive cuts.

Costwise, it is difficult to estimate. The parts of the table/fence/sled that you see in the photos cost me considerably less than $100. For the table in this initial version, I used a half a sheet of birch 12-ply plywood, at $40 a sheet. The graph cost under $20. Everything else I salvaged from other items in my shop.

Blades for bandsaws:

Bandsaw blade drift presents a key issue to bandsaw users. As I've found in my own experience, each blade seems to have its own personality. In the picture below, notice that the fence sets perpendicular to the track on the infeed side. That's because this particular Lenox blade (2½ tpi) doesn't have a blade drift, and so I use it all the time.

Photo 1 shows for my Laguna 18 inch bandsaw, (1) an enlarged table, approx 48 x 48 inches, and (2) a fence that combines wood and extruded aluminum.

The fence consists of (1) a wooden part, that stretches across the table from infeed side to outfeed side, and (2) an adjustable extruded aluminum bar, about 4 inches high. The extruded aluminum fence attaches to the wooden part of the fence, roughly 4” x 1 ½” by 4’, with ¼ “ 20 tpi threaded bolts. The heads of the bolts slide in a groove in the extruded aluminum. The bolts are tightened with the black knobs, seen on the right of the wooden part of the fence in Photo 1.

As shown in Photo 3, the wooden section of the fence includes roller bearings to reduce friction. The fence itself adjusts in two ways: (1) the wooden section is adjustable for blade drift (the three bolts on wooden part of the fence on the infeed side allow fence angle adjustment) and (2) the extruded aluminum fence is adjustable before and after the blade.

Locking the fence in place is easy. Since the fence is on the right of the blade, on the infeed side, it only has to be prevented from sliding to the right, and this is done with a clamp (also part of the salvaged jig) screwed to the track that the head of the fence slides in. On the outfeed side, the fence is secured from movement by a "stabilizer bar" (the best view is photo 8) secured with a threaded knob.

The plywood part of the table is screwed onto a frame composed of oak pieces, roughly 1½ " x 1" x appropriate lengths. The 1½ " x 1" oak pieces that wrap around the bandsaw's cast iron table are attached to the table with 8 ¼" bolts, i.e., two for each side. This "frame" also extends around the outside edge of the table, giving sufficient support to the plywood. The combination of this frame and the 3/4 ' plywood create a strong table. ( A diagram would be ideal, but I am not good with illustrations. See Photos 14 and 15.)

On the top of the approx 48 x 48 plywood is an approximately 1/8" thick plastic "graph" and “ruler”. This plastic is included for a variety reasons, primarily to help in measuring for cuts and for adjusting for blade drift, but it also reduces friction. This plastic graph comes from a fabric store.

Tilting the table:

I don't "tilt" the table, but with difficulty, it can be tilted. With the sled, using different kinds of wooden "angle squares" that I've made myself, I can make a variety of angled cuts.

On the right of the table, note first, the two parallel miter tracks for a sled, and, second, the adjustable bar, for stabilizing the fence on the outfeed side.


In Photo 2, note the ruler on the infeed side and on each of the other sides. Useful for setting fence at regular increments for resawing veneer, or just resawing to width. Also note biesemeyer-like track mechanism for setting infeed side of fence.

This "track" I cobbled together from parts cannibalized from an elaborate jig, mostly extruded aluminum, for cutting plywood panels. I purchased this jig at a woodworking show, but found that when set up permanently, for the amount of use I was getting from, it ate up to much real estate in my shop.




In Photo 3, note roller bearings under fence. When I first installed fence, because of friction between fence and table top, even with plastic surface, maintaining the angle, whether a 90º or a special one for specific blade drift, was dicey. Now the fence moves with ease, but temporary "fillers" are needed in the tracks where the roller bearings pass over. The two parallel miter tracks are for sled.

Photo 4 illustrates the set-up for the featherboard(s). First, the track that the featherboards slide in is itself held securely in two parallel T-tracks perpendicular to the fence. Second, the slot in the track allows the featherboards to be set "before" the blade, and, if needed, "after" the blade, on the outfeed side of the table. The featherboards themselves are flexible; i.e., for ripping, one layer is sufficient, but if needed for resawing thick pieces, the height of the featherboard can be increased by adding needed layers on top of the base layer.






Photo 5 gives another view of the featherboard mechanism, including the black adjustable stop, on the outfeed side.(There is no Photo 6.)



P6160047.jpg
P6160047.jpg


Photo 7 is the first of several that show the sequence of resawing a rough sawn piece English walnut. The bark is being saw off first, in preparation for resawing into veneer.




P6160049.jpg

Photo 8 shows the bark cut off, creating an almost square workpiece. However, the two sides are run through a jointer, to flatten the surfaces and make two sides square with another.



Photo 9 shows two things, first the half inch "slab" cut off the English walnut workpiece, and second, on the right outfeed side, the threaded knob for securing the stabilizer bar.

Photo 10 shows a caliper measuring the thickness of resawn veneer, 1/8" thick, or, as the readout for the caliper shows, one 133/1000ths of an inch. Cutting thinner veneer, to uniform thickness, is easy.

Photo 11 shows sawing timbers with the sled. Much more efficient than sawing with 10-inch table saw, skil saw, reciprocating saw, etc. Capacity for sawing timber is limited by the size of the bandsaw's throat, and, for longer and/or heavier pieces, capability of holding material steady while sawing. I could have photo that shows that the cut is square.

Photos 12 and 13 show 48 x 48 inch sheet of plywood setting on sled in preparation for cutting. Limited by size of bandsaw's throat, and ability to balance sheet on table. The set-up will saw accurately. The half sheet (i.e, 48 x 38 inches) is the unused part of the 4 x 8 sheet used for the table top.

In Photo 13, be assured that the table is level and square with the blade.


In Photo 14, above, but not captioned, the extruded aluminum track is attached to a board that, in turn, attaches to the front of the plywood table top. Without support, table top is weakened by blade slot. The board's purpose is to strengthen infeed side of table. (I think that for added support, two ¼” bolts, on eachside of the blade slot, need to be mounted.) Note threaded olt with black knob in Photos 2, 8 and 9. If further strengthening is required, to keep table from sagging with weight of workpiece, two additional ¼ inch bolts, one on each side of blade slot, could be added.

Photo 15: View of underside of table, showing framing bolted to bandsaw's cast-iron table. This set-up creates a very stable table. Also note that thetable-tilt mechanism is accessible.




Friday, December 23, 2005

Jigs for Creating Picture Frames with Compound Miters

under construction 1-18-07


This post shows designs for

  1. a jig for cutting compound miters for constructing picture frames
  2. a jig for gluing-up picture frames with compound-angled corners

I prefer to use a system for cutting the sides of picture frames that I devised myself for my radial arm saw. This system also works as well on a table saw.

My first photo is a picture of my Dad that I created out an old 4” X 5” box camera photo that I found in family memorabilia. The over-all dimensions of this frame are 19” w x 21” h, with the sides of the frame 3” w. The photo itself is standard 8” x 11” (I printed the photo with with my scanner and HP printer) but had the photo professionally matted. I also did a similar picture for my mother.


As well as barn wood, I have examples of frames constructed from molding that I have created with my shaper.


The frame in the photo below does not do justice to the frame’s 30˚ cant, a feature that gives considerable depth to the frame, depth that is missing when you simply glue up mitered frames at flat, 90˚ angles.


The photo of my Dad looks professional, largely, I think, because it is professionally matted. (For a joint funeral for my parents, I framed pictures of both my parents.) The racoon on the lower left is a Christmas gift for a friend of my wife. It's better at giving a sense of the depth of the frame that is obtained with the 30 degree slant on the frame's sides.












The depth the cant,
30 degrees, makes the frame, for me at least, quite striking. Photographed straight on, as for my Dad's (above) photo, this cant is hard to perceive.

Let me say that with more adept photography, the depth that the cant on the frame’s sides gives the picture an attractive appearance, certainly different than the rather heavy handed simple mitered corner look.



The material in the frame itself is old growth Douglas fir, taken from a 100-year old barn. Again, we live in the Puget Sound area of Washington State.





1. Cutting Compound Miters


The photo below, the four sides in prep for gluing, on the left, shows the angle or "cant" in the frame.

The photo on the right, directly below, shot from the side, gives you an idea of the angle/cant of the frame.




Experienced woodworkers will, immediately, understand that my technique allows you to overcome a difficulty inherent in working with "weathered barn wood." The charm of this media, the aged, "weathered" look, must be preserved, otherwise the appearance that you wish to achieve is ruined. Why? Once you cut weathered boards, a fresh cut is exposed. [will get a picture to illustrate soon]



The photo directly below is an "end" view, showing for the jig (1) the 30 degree angle, (2) T-track (for precisely cutting lengths of frame sides. and (3) aluminum "angle iron", for a precise cutting of the frame's sides.












[more description of T-track and related matters coming]














Note on photo on the right that along the lower edge toward the side of the jig, toward the viewer, is an aluminum angle iron. (See also above, end view of jig, where angle iron is easily viewable.) One side of the angle iron is attached to the jig itelf, while the second side of the angle iron etends upward and holds the stock, on one side or another, at a uniform position while the miter is cut.




















In creating a frame, I first cut the rabbets. Making the square rabbet.

Again, my saw blade is set at 30 degrees. I place the fence to the right of the blade, just far enough that I able to place the kerf line exactly on the corner of the weathered board (check the blade's location in both left and right photos below). For the next cut (no picture yet), I move the fence over to the right, lay the board on its side, so that the cut cleanly removes the material and leaves a square rabbet, as illustrated in photo directly above, on right.






































The photos above show the jigs that I created for the cutting
on a radial arm set-up the compound miters for the frame’s sides . ( I can also show how it could be done on a table-saw, or of course my Hitachi compound miter saw. On the Hitachi, the jig wouldn’t be required, but the cutting operation would involve other complications, I think. )







photo from outfeed side of table saw







My jigs let woodworkers who lack the compound miter saw to easily make three dimensional frames with compound miters on the tablesaw. [will have more pictures and description soon.]


In the photo above is illustrated a downside of using weathereed barnwood. Every cut exposes wood that is not weathered. To avoid exposing these cuts, I cut the picture frames sides so that these exposed areas are always on the inside of the frame, "inside" in the sense that when the four sides are glued up, the cuts are located where the picture is placed in the frame.

Setting the saw blade at 30 degrees, I make two cuts, that form a "square rabbet". (See photo below, on right.) This square rabbet is cut so that the exposed, "fresh" wood is all eliminated, with the weathered frame sitting next to the matte, between the frame and the picture. For an example, look closely at the framed photo of my father, at the top, and focus on where the frame meets the matte.


2. Clamping System


The clamping system I use is from lee valley, but the clamps look very similar to WS catalog no 139-745. What I did not see in your catalog was the “ring”, important for holding the four clamps when the frames are glued up.




















These photos, above, on the right, and below, show several features about this system: Use of biscuits for better glue up on compound angles at corners. Specially created clamps for holding angled corners securely, with surfaces tightly held together by metal “clips”, while glue sets.

The photo above below shows the final clamping set up. I pondered this problem (i.e., how to glue corners with compound angles) for many years, and, when I saw this clamping system in the Lee Valley catalog, finally settled on this solution. If there’s a “secret’, it is the clamps that I have created, which during glue up, with the aid of the metal “clips”, hold the surfaces of the compound angles tightly together, very important if the glue up is expected to last.

[needs editing] For the glue-up, the corner frames that I made have metal “cleats” that, corner by corner, apply pressure uniformly. (I bought the clamping system at lee valley store in coquitlam.) I was surprised myself at how efficient this clamp is. The clamping set-up itself I bought at lee valley. Before I thought of this solution, for glue-up, I used a brad nailer to hold one corner at a time, not a satisfactory way to go.

As the photo below shows, the picture frame clamps are simple. I made mine out of scrap wood and sheet metal. I think that equally effective clumps can be constructed out of plastic. If there is a downside, it is that the angle (in this photo, the bent metal “clip”) that helps secure good surface bonding is “fixed”. In this case the angle is 30˚. How make this clamp with an adjustable angle has, so far, eluded me. More important, is an adjustment mechanism needed? Most frames will be satisfactorily glued up with 30˚ cants. If other angles are desirable, plastic clamps with a variety of angles can be offered.


need better photo than above

The photo below shows the picture frame's corner at a different angle.

"Sizing" the frame to the matte. [need details here about difficulty of measuring appropiate size of frame's rabbet.]







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Link: http://raymondmcinnis.blogspot.com/