Mel Lammers graciously published directions for making a leather belt case in the Pilot newsgroup. What follows is my interpretation of those written instructions -- Mel is not responsible for my changes to his design.
There's also the question of investment in tools, if you don't already have such oddities as rivet setters and punches on hand. (You'll certainly have a lot of leather dye left over.) What I did was make a half-dozen holsters and sell them, with Mel's blessing, priced to break-even when the last one sold. If you are ambitious, you're welcome to carry on the tradition. I would suggest you plan on throwing away the first couple of prototypes, though; and you should wear your own work for at least a month or so to make sure it stands up to daily use before you offer it to the public.
Leather thickness is measured in "ounces per square foot"; 5 ounce vegetable-tanned leather is a bit over 2mm thick. It has two sides, the smooth "hair" side and the rougher "flesh" side. You'll need about two square feet of 5 oz. "tooling leather." Talk to the store personnel about what's available on their scrap table; you don't want to buy an entire "side" or "shoulder" unless you plan to take up leatherworking as a hobby... which could happen, come to think of it!
From craft, hobby, or sewing store:
Construction details
Being a natural product, a large piece of leather will have some spots where
it is thicker than its nominal weight. Pick out two of these thick areas to
make the back of the case. They should be simple rectangles, more than four
inches by five inches (11 x 13 cm). Don't try cutting the pieces to exact
size yet -- in fact, make sure you've left plenty of margin to trim away later.
You also need to leave a large enough piece for the front, at least a
six-inch square (15 x 15 cm).
The outside needs two oblong holes to accept the heavy-duty nickel-plated interlocking belt clip, which is riveted in place at the bottom. (For light use, you can get by without the rivet if you cement it in place.) You can make these holes with a sharp No. 11 X-Acto brand knife, but it's worth investing in an oblong "belting punch." You can dampen the leather slightly to make it easier to cut or punch. Let the leather dry, then fasten the clip in place with contact cement and/or a rivet. Make sure the smooth side of the leather is facing out.
Complete the back by gluing the rough sides of the two pieces of leather together. We'll be using contact cement, the thick yellow-green rubbery kind. Use this in a well-ventilated area -- the fumes are terrible! Coat the rough sides of both pieces and let dry for fifteen minutes before pressing the layers together firmly. Lay this "sandwich" down on a flat work surface with the clip facing up, and tap all around it with a wooden mallet to insure there are no gaps in the cement. Then put heavy books or other weights on each side of the belt clip, and let the bond dry for an hour or so.
The front of the case is wet-formed over a wooden model of a Pilot. (I went a little overboard with mine! The scroll button area is built up from epoxy putty, and the "power switch" is a strip of sheet metal, epoxied into place. A simple block of wood would have worked just as well, though.) A PalmPilot Professional and a III series have the same width and height, unless the III is wearing its removable flip cover; you can use the same holster for both models. A backing board provides a rim about an inch wide, but not too thick; we need to fit C-clamps over it. Drive four screws through the backing into the mockup. Use washers to separate the mockup from the backing by about 1/8 inch (or the thickness of your leather). Later on you will want to use the mockup without the backing board, so make sure you can unscrew it without damaging it. Drill pilot holes so the mockup doesn't crack or split.
Soak a piece of 5-oz. leather in water for five minutes. It should be
large enough to cover the entire form with a good margin all around -- at least
six inches (15 cm) square. Wet leather will stretch quite a bit. The idea is
to make a rectangular "cup" with a flat margin on both sides. This margin
will be glued, riveted, and sewn to the flat back. Use flat sticks, like
paint stirrers or Popsicle sticks (sold as "craft sticks") to keep the front
snug against the wooden form on both sides and the bottom while it dries and
takes the shape of the mold. Make sure the finished side is facing out;
later you'll be covering the rough inside with self-adhesive felt.
You'll need to stretch, squeeze, and tease the leather to form the bottom
corners. A flat wooden stick for poking is very helpful here. The leather
may try to fold or take a crease, but if you are persistent you can shape it
almost like plastic instead. Don't settle for a folded corner -- stretch
it into shape. A heavier piece of leather (8 oz. or so) makes for a
stiffer and more protective holster, but in order to form it, you would
probably have to "skive" (thin) the corners; it's better to use a
lighter piece of leather.
If you want to get fancy, now is the time to impress a "basket weave" pattern, your initials, or any of the other artistic things that leather crafters do to express themselves. The Tandy catalog may give you ideas, or you may just want a plain professional or high-tech appearance. This is when I'll stamp my company logo (using a metal stamp which Tandy produced from my original artwork -- this is quite an investment unless you plan to do a lot of projects). Creating a custom monogram is an interesting artform in its own right; instead of a single stamp, the outline is cut in using an X-Acto knife, and the outlined area is then permanently stamped using a variety of tools. One has to work carefully but also reasonably quickly while the leather remains damp.
I also use a technique called "boning" to pick up the exaggerated features from the mockup beneath the leather. This involves pressing and rubbing the leather with a plastic tool, similar to a small spatula. The compressed leather takes on the shape of the underlying mold. In the days of the original Pilot with its distinctive double-curved bottom, this made for a very striking sculpted appearance, as the drawings on this page show. Recent Palm designs are more subtle, but it still adds a touch of distinction when you echo the slight bulge (the finger grip) on the flip cover of a IIIx, or add a bit of extra relief to protect a button.
This is also the time to avoid making any dents or dings. Wet leather "remembers" what you do to it, for good or for bad. Be careful with your fingernails! Let the damp leather dry naturally; do not subject it to heat or direct sunlight. (If you do, it will become brittle and its surface may even crack.) Let it dry thoroughly and slowly, overnight at least.
Now you can cut the front roughly to shape, but leave a little extra -- cutting it too small now will make it impossible to assemble the holster. Note how the sides are cut away at the top so you can get a good grip on the Pilot. Heavy scissors are probably the best tool for this initial trimming, or the X-Acto knife with a steel ruler to use as a guide.
Carefully place this metal plate inside the leather "cup"
so that it will overlap the screen when everything is assembled. If something
presses in on the holster, the metal sheet should spread the force all around
the frame. If an edge of the sheet misses the frame, it could bow or even
bend inward and allow the screen to be crushed. If you're not sure that you
can place the metal that accurately, you might want to make it extra wide so
as to cover the entire front of your Pilot and wrap around slightly on
each side. Secure it permanently with contact cement (coat the inside of the
leather and the outside of the metal sheet, let it dry for ten minutes, then
press together firmly). It's important that you avoid getting cement on the
finished (outside) leather surfaces -- dye won't penetrate glue and the
result will be awfully splotchy. There is an opaque paint sold as "Edge
Dressing" that can save the situation, but using it this way is definitely
a last resort.
There's a technique called "skiving", which is shaving or cutting
away some of the thickness of leather. I skive two strips, half-an-inch wide
by an inch and a half tall, so they are paper-thin at one end. They act as
wedges to grip the base of the Pilot firmly when it is fully seated, yet
release smoothly as it is pulled out. Cement these inside the cup, one on
each side, at the very bottom. For a III series Palm, you might be tempted
to make an elaborate nest for the tapered lower end, but it really doesn't
matter; the rectangular cross-section still determines the overall fit.
The next magic ingredient is Presto brand self-stick felt, available at fabric and craft stores. It's surprisingly tough, adheres well, and provides a surface that will be kind to your Pilot. Line the back with a rectangle just the size of your Pilot. You can line the inside of the leather cup with individual pieces, but I prefer a single larger piece for a seamless fit. Cut away the bottom corners so the sides and bottom can fold in. If you have a Pro, study the side where the contrast wheel is in danger of rubbing against the case -- you'll want to cut away the felt here, so you don't have to readjust your Pilot every time you pull it out. Don't let the felt cover the flat rim where you'll be gluing the front to the back! When you have the shape correct, peel away the paper backing and press the felt into place, working from the center out to the edges.
Line up the front with the back and adjust the fit so that your
Pilot will be held snugly, but not so tight that you can't pull it out.
Now's a good time to unscrew the mockup from the back board and use it to
help line things up. It's better to make the holster a little too tight
at first -- leather stretches with use. Apply contact cement around both
side edges and the bottom, and remember, when that contact cement meets,
it's forever. Tap the seams with the wooden mallet for luck.
Even with practice, it's all but impossible to get a perfect fit this way. You'll need to take advantage of leather's forgiving nature. I made yet another wooden mockup, this one cut slightly oversized with a generous handle. Once the contact cement is thoroughly dry, I force this oversized model into the pocket several times and work it around until my Pilot goes in and comes out with no effort. Properly fitted, the real Pilot will not fall out even if I hold the holster upside down and shake it, yet I can "draw" the Pilot as smoothly as a wild West gunfighter.
Mel's original design was stitched all the way around with linen thread. I added small rivets on mine where the top opening has the most stress, and used just a few bar-stitches on the bottom corners. The glue is effective, but the limiting factor is the tensile strength of the leather itself, which can pull apart in layers. For that reason, a bit of stitching is a good idea. Traditionalists use two needles so even if a thread breaks the seam remains sewn -- the needles sold at Tandy come with instructions. If you decide to try stitching by hand, Mel recommends you pull the needles through with pliers to spare your fingers. I suggest the "Awl for All" stitching tool; it's easy to learn, inexpensive and produces a lockstich like a sewing machine. I'd also buy a small leather punch, one that makes four stitching holes with each whack of your mallet. That insures your stitches are evenly spaced. Four stitches on each bottom corner should do the job.
You should still have lots of extra leather around the margins. Time to trim the case to size. Tinsnips or very large scissors will do it, though the result may look a little bedraggled. A sharp X-Acto knife is another way, though it's awfully easy to slip up and ruin a lot of hard work. Still, it's better to use a really sharp blade that works with little force than a dull blade that tricks you into pressing so hard you can't control it. Leave a full quarter-inch of glued seam or even a bit more, all around the case. Once you've got the case cut down to its final dimensions, Mel's secret is to use a belt sander or grinding wheel to finish the edges. Those rough edges will take on a finished appearance in no time with a little power-driven elbow grease.
Apply the leather dye of your choice. Oil-based dye works very well, but
involves wicked chemical solvents (even worse than that contact cement).
There are less offensive water-based dyes that work almost as well.
But whatever type you use, be certain to wear rubber or plastic gloves! This
stuff does not wash off. The way to apply the dye is with a wool
"dauber" available at Tandy. It's just a ball of sheep's wool with a wire
handle, but nothing else works as well. They come in bundles of a half-dozen
or so.
Also pick up a wooden or plastic tool called an "edge slicker" -- it's only a dollar or two. The Tandy salesperson can show you how it works. It's a flat spool with a rounded channel around the circumference, and is used to round and smooth leather edges by compression. After that you can apply a coat of "Edge Dressing," a thick paint-like substance, to seal the raw edges and give a finished, professional look.
After you've given the outside a couple of coats of dye and it has thoroughly dried, finish the job with acrylic clear coat to protect against casual moisture and keep the dye from rubbing off on your hands or clothing. Tandy's house brands are called "Super Sheen" and "Satin Sheen."
