versions – MossGoblin

Elegant 2.0 – tape finish and result

I skipped a photo, I think. There should have been one showing the rough cut.

Anyway, it was (as it should be) the most nerve wrecking part, cause you can’t undo the cutting. And the experiment with a double core made me anxious, because I had 20mm I had to avoid in the middle, instead of 10mm.

Anyway, I cut the shape, then beveled it as much as I could. Here is when I found that the core is too long, should have kept it ~30mm shorter (see at the end).

Here’s the tip after beveling:

Then… the hell begins.

I don’t have a belt sander (nowhere to mount it, at least) and I currently don’t have a rotary tool, so I had to do the sanding by hand.

Technically sanding was not necessary for a training sword with a lot of new and untested stuff, but I did it for the XP.

And yeah, 100% density EVA foam makes a mess.

The good thing is that the dust does not pick up static electricity. It inevitably ends up beyond the boundaries of your working area, but at least it’s easy to vacuum later and even clean by hand from the smooth surfaces.

This part of the process is wide open for improvements.

Then there’s a part that is again not necessary for duct taped training weapon, but I did it for consistency – passing over the sanded areas with the heat gun. At the least, it gives great satisfaction to see the foam cells close in a wave under the hot air.

You can still see the roughness of the surface. That’s because I did the sanding by hand and also used only one size sandpaper – 80. In an ideal world (proper power tools) the sanding would be much finer with a 120 after the 80, may be with an even finer grade at the end.

Also, the cuts between the grip and the blade are not perfect. Again – good for a training sword.

Yup, last portion – the covering.

Here’s what’s important to have in mind:

I don’t have a way to prevent fragmentation of the tape at the tip – it is what it is, the duct tape does not bend, so there will be a lot of cuts.
Concave parts of the edges have to have separating cuts – the stronger the curvature, the closer the cuts to each other. This results in empty ‘slices’ on the sides of the blade where the cuts are made (it will start making sense in the photos).
Convex parts of the edges will also have such cuts, this time to prevent wrinkles. And the concaveness means the pieces surrounding the supporting cuts will overlap. So at least they should overlap in the same direction (symmetrically on both sides of the blade).
Some parts of the sides of the blade need to be covered before anything else, to ensure that when longer, more conforming to the shape strips of tape are put, there will be no visible foam around them.

First – initial layer for the tip of the tip.

Place a piece of tape.
Make radial cuts, starting from the tip – this will separate the tape into portions that will cover the tip from different sides, while keeping the tape at the tip of the tip continuous.
Fold.

A bit ugly, I know.

Then lay in the ground work for the back side of the blade. Most of this will be covered with another layer, but we need to make sure everything is covered on the lowest level.

You can see here the empty patches left when you make the supporting cuts along the tape. And you can not avoid the cuts, because:

a) curvature (negative; curse you, Gauss!)

b) non-stretchiness

Usually, I place thin supporting tapes below that, but I needed Q.E.D for the photos. So now I’ll place the tapes above the… fractures (I like that term for this, I may continue using it).

Here are those supporting tapes around the concave portions of the edges.

Aaanyway. After the thin strips to support the concave curvatures and the wider patches to cover the tricky bits, it’s time for long, full width strips to cover most of the blade.

I could go full length, but it’s easer to prepare a tape not longer than my cutting board. Also, for a training weapon, it’s good to have long continuous strips of coverage, but it’s not a disaster it you do not cover the whole edge in one go. The longer strip you try to use, the more unwieldy it gets, so at some point it’s not worth the trouble and the risk of a sticky tangle.

So I start by covering about 60cm, starting from the back of the blade.

Then we start on the tip side of the blade. The edge is convex, so the supporting cuts will overlap (as I mentioned above). We can place a long full-length strip right away.

Position it on the edge itself, make supporting cuts – close together where the curvature is greater, sparser apart where the edge is almost straight. Then start applying the tape to the sides. And for both sides of the blade, start applying in the same direction – top to button or the other way around. You want the overlaps to be symmetrical.

Covering the small leftover areas at the bottom of the blade is trivial.

I added one last layer of tape, making sure the longest straightest strips are on top of the more fragmented ones. You can go up to 3-4 layers of duct tape before starting to lose flexibility in any noticeable amount.

Last place to be covered with duct tape (for this sword, at least) – the pommel. The design calls for small to non-existent pommel and I have left it as simple as possible (only with slight bevel on the grip edges).

I only need to cover the tip of the pommel and may be 1-1.5cm of the grip.

Several overlapping thin strips of duct tape around the pommel – for visual structure, mainly. And also for a slight increase of grip width (the rest of the grip will have 2+ layers of electrical tape, so I don’t want the pommel to end up tapering off).

The electrical tape I did not take a photo of (got distracted). But there’s nothing tricky there. Using electrical tape is easy – it is relatively stretchy, so you can cover curvature with a long continuous strip. This makes it easy to cover the boundary between the blade and the grip.

All in all, here’s the result.

Aaand it’s done!

Here it is by itself and with v1.0.

How does it feel? Heavier. And you can tell that it’s not the foam itself. The core felt heavier to wield even before the sword was assembled and now that it is ready you can tell the core is heavier.

We’ll see, the double core was part of the planned experiment.

The sword is definitely too long for me (for one hand, at least), but it’s not for me, so it’s ok.

Problem – The core is too long for this sword. There is about 10mm of foam left at the back end (the pommel), in order to make sure the pommel is well supported (see problem 4 with v1.0). So the core is pretty close to the back of the weapon. And yet, the tip of the blade has only 50mm core-less. This may sound like a “no-problemo” for a straight edged weapon, but not for a curved one. I ended up lacking the freedom to make the curve as smooth as I would like. Also, when I beveled the edges, I could not do it with a smoother, larger bevel, because I would end up exposing the core at the middle of the edge curve. Bad planning. Note to self.

Question – The grip is wide enough (or at least wider than v1.0, as planned), but… is it thick enough? I could have added a 3mm foam strip on each side and that would probably have improved the profile. If it turns out that the grip as it is is not comfortable, I may end up trying to re-do it. As it is electrical tape only, it may prove… possible.

We’ll see!

Elegant 2.0 – gluing it all together

So, I left it aside for a while, cause I had to quickly put together another sword.

(It is my first long sword, so I left it undocumented, mainly because I don’t like to document the experiments, but also because I was pressed for time. Perhaps I will place here it’s second version. We’ll see)

Getting back to it, my next step is gluing the layers together. One thing that I find annoying in my current layer choices (3mm, 10mm, 3mm) is that I trace the silhouette of the sword on the main later (the thick middle one), because I need to mark and cut out the slot for the core. However, when I make the foam sandwich, I need another tracing on one of the sides, so that I can actually cut the silhouette. And both tracings need to match (at least to a reasonably high extent). So… Double work with some chance of mismatch. Sloppy.

Anyways, I got the thin layers cut to the same starting width – 80mm.

Cutting it down to size. The sword will be 90cm total. The foam sheets I’m using are supposed to be 1×2m, but it turns out the short side is actually a bit more (I have not checked the long side). Irrelevant in this case.

Here I am missing a photo. As I mentioned, here I trace the dimensions of the groove on the thick layer. Here’s the tricky part:

The core is being brought up to a thickness of 10mm (by the use of electrical tape), but the sides of it are still rounded. If I cut a straight groove in the foam, the sides of the core would not fit well. The space there would be too large for my peace of mind. I want the groove to be as close as possible to the cross section of the core, so that I can really count on the glue.

So I need a cut with an internal profile. Something like this:

Cut it at an angle along each line, the blade pointing outwards, and you should get what you need. It worked surprisingly well.

(those are test cuts on a leftover piece of foam)

The middle part separates easily after the cuts.

If you are careful (and with some luck), the space left will comfortably accommodate the core.

And… a lot of glue – thin layer, thick layer with a well-covered in glue core, then another thin layer. Then fix in place with weights or clamps and wait for the glue to cure. We’ll see in a while.

What I learned:

Cutting the profiled groove: I estimated that if the groove should be a little more than 20mm at it’s widest (in the middle of the foam), then I should make my cuts a little more than 10mm apart. This needs to be a bit more… calculated. I ended up with a groove that is a bit too tight for my liking. Should have ended up with another 1-2mm. Anyways, it was not a disaster.

Cutting a profiled groove: Using the craft knife is not perfect – the body of the knife gets in the way. I’ll start using a blade only, with a marking for the depth of the cut.

Elegant 2.0 – core, foam, basic dimensions

Easy part – getting the basic dimensions of the foam. Version 1.0 of the sword is still around, so I could easily cut a piece of foam for the main layer. The sheet of foam I have is 100cm length, so there will be some leftover, but I don’t consider it a loss at this point, cause I use those pieces for practicing my cuts.

I’m starting with this:

Foam: 8×100cm EVA foam, 10mm, 100% density:

The first version has a single rod for a core. It is not too flexible, but we decided to try with two to explore the differences. 85cm rods to accommodate the lengthening of the blade, compared to v1.0.

Then comes the width work.

The rod is 9.5mm thick, while the foam is 10mm. It’s kind of fortunate, because the rods need to be tightened together into a single core. This will require a couple of layers of tape, which would also take care of the width discrepancy.

One layer, two layers, double core:

So far so good. Cutting next time.

Elegant v2.0 project (Elegant 1.0)

A second version of an already made sword.

Idea: side sword, single edge, curved at the end (reference image below), training sword (duct tape finish)

Reference notes – curvature in the top third of the blade, curvature of the grip, no guard, no large pommel, grip length – standard for side sword

That was my first sword with glass fiber core and EVA foam. The result was encouraging.

Feedback from the first battle test:

Preference – Should be a bit longer (~5cm)
Preference – The grip should be wider (~1cm).
Preference – The widening at the back before the tip should be removed, along with the false edge.
Problem – the end of the grip (where the not-pronounced pommel is) suffers a bit – the sword is generally used with one hand, but the second hand does help from time to time and the end of the grip is not supported (the core does not extend all the way). May be this should addressed.
Problem – As the layering at the moment is 3 + 10 + 3mm, the boundaries between the closing 3mm later and the main 10mm layer are prone to heavier tear (see below). I’ll try another layering later on, but for now I’m stuck with this. Clearly this works only for training weapons (duct tape finish). For spray-and-paint weapons I’ll have to revert to two-layered pattern (the way most people do it on the net, see Resources).
Hidden problem – by mistake the weapon is actually made out of two parts – the blade and the grip were separate and currently being held together by elaborate pattern of electrical tape ‘wiring’. I’m waiting to see how long it will take for the sword to break apart during training at the grip. It is quite a light sword, with good balance even without weighting, so the sword may live longer that I initially anticipated, but… we’ll see.
Problem – the core of the weapon is a 9.5mm rod, while the main foam layer is 10mm. I did forget to compensate that, so you can feel that there is a hidden groove in the blade. This means that the glue does not pull it’s weight and the blade is prone to dismantling.