I've been searching the 'net for 3 or 4 days now for information on reel design, and this is so far the most relevant result I have found. I wonder if you would mind me asking a few questions about a design based on fishing / speargun reels, but used for other applications?
I have several preliminary designs drawn up, but I learned long ago that whenever I am designing something, it is best to assume I know nothing and go to the experts on that subject - so here I am! I am mainly looking for hints, critiques, and suggestions about the actual reeling mechanism, but if anyone has any ideas about the rest of my design idea, please let me know!
I and some friends have come up with an engineering challenge for one another - this may seem a bit 'geekish' to most of you, but it is something we do for fun. In this challenge, we are to design and build a weapon based upon one found in a video game - a sword that can turn into a metallic whip. Further, we are hoping to be able to do so with a design that could have been crafted in medieval times, though that is just a bit of a 'bonus' as it were.
In my design, I chose to start with a 40” total blade, and extend to 4x its length, 160”. Adding in a handle of roughly 8” or so yields a 14’ reach, just shy of the ‘standard’ 15’ bullwhip. As detailed below, I will use two lengths of wire, each fed through the blade 4 times, causing each to be 644” total, with 163” remaining in the blade when fully retracted. That leaves 480” to be fed onto each spool. (There are two spools, each of which takes half of each of the two wires). I know my figures seem a few inches off here and there, that is due to the design adding a bit of sideways distance to the wires as well as traveling the length of the blade. At 24 gauge wire, I am thinking this may be a bit too bulky to fit onto the weapon – is anyone familiar with how large of a spool 480” of 24 gauge wire would require? I am afraid to go to a smaller 28 gauge, as even high-tensile may not be suitable for this application; but if I have to I will.
As I have it now (this is kind of hard for me to explain without using my schematics, so please bear with me), there are two separate sides; a double-edged weapon; each side has 20 blade fragments (40 total), and there is a 41st piece (the weighted tip of the blade) as well as the handle itself which has the reel mounted crosswise as the guard between the handle and the blade (instead of parralel to the handle as in a speargun or fishing reel). The blade fragments are connected by high-tensile 24 gauge wire running through pre-drilled grooves, starting at the 'spool', running the full length along the outer 'sharp' edge, into a 'pulley' in the tip of the weapon, back through the blade fragments just off center to a 'pulley' in the handle, up to the tip again for the final 'pulley' and then into a central hole to a second, inner spool. That is duplicated on either edge. So all in all, four lengths of wire running through each blade fragment; this is to help keep them aligned when retracting the weapon down into its compressed 'sword' form.
My approach is to apply the same basic technique used in a modern day ratchet driver (lock / spin only clockwise / spin only counter clockwise) along with a highly modified reel device to allow a few dozen pieces of sharpened metal ('blade fragments') to be pulled into a sword shape, or freed to be used as a very dangerous whip.
As mentioned, there will be two spools, one slightly larger set back closer to the handle and one slightly smaller set closer to the blade. They will both spin perpendicular to the handle/blade, unlike a fishing / speargun reel that spins parallel to the handle. They will also both handle half of the wire from each side of the blade (there are two separate wires, each traveling from the larger spool through the blade fragments and onto the smaller spool) - this is the first portion I am unsure of. Will this cause potential tangling and mis-feeding of the wires?
Second, in theory the ratcheting system should be simple - a lever of sorts (probably the pommel / bottom of the handle) is turned one way to extend the weapon, and turned the other direction to retract it; when in the 'center' position it locks the spools from spinning in either direction. I would like to have it automatically lock whenever it gets fully extended or fully retracted, both to keep from accidentally switching from one form into the other, as well as to keep any extra and unneeded tension off of the spool mechanism. I am not yet sure how that will be accomplished.
Also, as I described it, I can envision the weapon theoretically working as desired to extend the length and then retract - the tip of the blade will be weighted, when the catch is released you simply cast as if a fishing rod and it extends out. Then you wind it in again and with the pulley system and 4 guide wires to keep the pieces of the blade aligned properly, it will fit together snugly again. However, there is nothing to keep the blade fragments at any certain position - and I see them all sliding forward to the very end of the weapon, making it poorly balanced and unusable as a whip. But any means of keeping them secured in a certain position (preferably equidistant along the full length of the wire) would also hamper retracting the wire in fully. So that is one design flaw I know of already, but am unsure of how to correct without starting with a totally new concept.
I do have a bit more detail fleshed out, but it is really hard to describe without showing the sketches, and I think I have provided all the relevant information for the questions I have asked. Again, I know this isn’t really 100% related to designing a speargun reel, but it seemed close enough and from reading this you guys have a good idea of engineering such a device; so I hope you don’t mind me posing the question here!
Thanks!!!
