now, I am not entirely sure if it's the same way everywhere, but at least in the con's I've gone to, carrying metal swords is forbidden, or, if allowed, it is forbidden to unsheathe metal swords, weather they have edge or not.
Also, let's face it, a true sword, even a prop metal one is not exactly cheap
Wood Sheets [1 of (5 to 7)mm and 2 or 3 of (7 - 10)mm] (I recommend you read the rest to explain why the sizes and amounts)
--- here I am using basswood, for all of the sword, first, because it's a soft and easy wood to work/carve, and secondly, because I don't have power-tools to work with harder woods, but if you do, feel free to use them, and use harder woods.
Cutter (like a snap-off blade) / wood-saw or other wood cutting tool
Paint / spray paint (silver/metal, gold/bronze, and black/brown)
flat shoelaces (not the rounded ones) / seam-cloth (sorry, don't know the actual name)
Step 1: Step 1 - Study Your Swords
so, yeah, there are plenty of pages around where you can find the makings of a katana (or other swords in general, actually). And, most importantly, it's parts
image isn't mine, there are quite a bunch of images in google, and names, and stuff
se sure to also considered exactly how much detail you want to add
Step 2: Step 2 - Measure and Cut
I'm *sigh* a rather small person, thus, having a normal sized sword would not be beneficial for me (what purpose is a sword, meant to be unsheathed that you can't unsheathe due to its size, after all)
so, use some replacement for the sword (a broomstick or something) to check the length the sword can have and you can still unsheathe
- important point here, the place you have your hand in is not the true length of the 'blade'
then go to your first wood sheet, the slimmest of the group, this one will be the swords blade
a good size for this one is 5 mm / 0.5 cm. I put an optional 2 mm extra because, for my first sword, I was really two scared of the sword's stability with the basswood that I made it a bit thicker, just as a precaution; turns out it's also fine with 5mm, just, remember they're meant to look cool, not to hit things (neither the 7mm nor 5mm one).
so, you go to the first sheet with the measure of the blade
Remember what I said that the place where you put your hand is not the true length of the blade, well, that's because of this
where you're putting your hand should actually correspond to where the guard is, otherwise, you'll end up with a blade far too long for you (and you either coupe with it, or cut it a bit)
now that you left a part for the (inside of the guard). Use a tube or something that can bend softly to create the curve of your katana (cause katanas do have curves). and draw over your wood sheet the line you'll follow to cut
a good width for the blade is 3 cm, so make it that the blade has 3 cm of width through out the entire length of the blade, later on you can make the point a bit less wide
and now to cut
Step 3: Step 3 - Check, Doble Check, and More Cutting
So take your 'blade' and check how unsheathing would be with this one, remember now you know where the tsuba (guard) and tsuka (hilt) of the sword go, and thus, where your hand will truly go when unsheathing
if the size is comfortable, now it's time to start the more detailed aspects of the sword
but first you must make some more cuts to the 'blade'
Step 4: Step 4 - All the Little Parts
it is entirely up to you if you want to recreate all of them
the kashira is ... like a seal of sorts, it is used as protection as the ending part of the hilt, and also to keep the tsukamaki (the cord) knotted
the fuchi is on the oposite side of the hilt, where the hilt is next to the guard, and it also wraps its end
the hilt, here I cut out of the two sheets of thicker basswood, made a canal (the canal being half carved on each side of each sheet) that fit the hilt part of the 'blade'; and pasted it together
the mekuni is a... safe... a little wood (or bone, I believe, in a proper katana); that is what prevents the blade from slipping out from the hilt
the habaki is like a holder, the last part of the hilt and the first part of the blade. I don't know if it has a specific use, but at least for me, it is what keeps the scabbard from slipping open (just tight enough)
the parts here shown (and their order in the sword's hilt)
Tsuka (with the cord and other decorations)
Menuki (still inside the tsuka)
Fuchi (collaring the blade end of the tsuka)
the second Seppa
and the blade
Step 5: Scabbard and Putting All Together
I believe I found a video that showed how to clean the blade of the katana, and for that, how to disassemble the katana; what I found, was that the habaki is what keeps the seppa and guard from slipping to the blade side
that meant, for me, that I had to shape the habaki so that in entered through the hilt side of the blade while making and placing it; just like the rest of the hilt's components
building the scabbard was pretty much the same as building the hilt, this time, though, it was using the rest of the two thicker wood sheets, and likewise, carving a canal thick enough, and with a curve, (using the katana as a model) so that the 'blade' can easily slip in and out. and then pasted it together.
also, be careful with the Habaki, the idea is to make the scabbard's canal big enough so that the blade doesn't suffer (so that it doesn't scratch the paint off) when unsheathing, but, be careful not to overdo it, and where it must also take into consideration the habaki, make the scabbard tight enough so that the habaki can keep the scabbard in it's place when lifting the sword (and scabbard) by the hilt (don't let the scabbard fall) but be careful also not to break the habaki with too much pressure
the cord around the scabbard is... kind of optional too, depending on how realistic you want to make it look; I found a few pages that told what kinds of knots to use on a scabbard (this one is mostly decorative; but in case you want to make one such, do consider, you will need to add the Kurigata to the scabbard, which is a kind of little bridge, so that the cord can hold.