• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

help me design a reel

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Certified SCUBA Rider
May 7, 2002
my latest gear obsession has turned to reels. i'm really interested in trying one out, but cant afford one at the moment, so i'm thinking of making one. here at the varsity workshop we have all the required machinery (lathe, mill, drill press, welding stuff), as well as a lot of metal offcuts etc, so the only thing i lack is a decent design.

I was thinking along the lines of ss or ally for the housing, with a nylon spool. the concerns i have are the bearing, as the reel will be always used on a shore entry, and that usually means a lot of sand.

also the size...the fish arent likely to be big. probably max 10 kilos, so how much line, 20m, 30m?

please share all your ideas, big or small

A guy I once knew, a long time ago before I started spearing, had two guns - the one had a penn Jigmaster attached to it, the other what looked like a coffee tin on it :D

I'd think the biggest problem would be the braking mech, or at least a ratchet type thing to slow the fish down. Maybe look at fly-fishing reel's design to see how they operate - they've got some fairly simple designs in there that could be copied. Keep us updated!
i've done a bit of R&D, for the bearing there are two design types.
1. the spool turns on a shaft, which is supported at one end, with a stopper of some sorts on the other end (to keep the spool on). so the shaft that holds the spool as a cantilever, like putting your finger through a spool. riffe uses this design. the winder is simply attached to the outside edge of the spool.
probably good for large diameter, narrow thickness reels. also allows horizontal mounting.

2. the shaft is fixed to the spool, and it rotates on two bearing surfaces on the outside of the spool. the bearing surfaces are part of the mounting system, so it is held at two points, like holding a spool between thumb and forefinger. the winder is a lever that is fixed to the shaft. this would probably work well with small diameter, large thickness reels. vertical mounting would be better, i think.

option 2 looks easier to build, and is stronger design wise, so i can use lighter materials.

as for the drag, i was just thinking of a friction screw.
an uprated design would be a screw on a pivot, so when you reel in it just moves out of the way, but when it is pulled, it locks up. make sense?
more complex though and more can go wrong.
I guess - I was pretty shocked at it. This was back in ... urgh giving away my age again ... the late 80's - probably around 87 or 88. I mean these things were brand new then ... he had a lot of dyneema on it (although it was probably called something else back then)
I think you might be onto something about the friction screw ... and I thought only 'boere maak planne' he he he
ok, i've got my basic design, now i need to get the right sizes. i need help wrt the length of line to use.

this is my diving for intended reel usage:
max 20m deep, fish max 15kg, if i'm lucky, but mostly around 5kg.

another point is the strength of line. i assume stonger line equals less line, but i'm trying to make the reel as compact as possible, so i'd rather use a line that fits the purpose, instead of yf tuna stuff.

my design is a made out of threaded bar, nuts and big washers, mounted to steel plate bracket.
its horizontal mount, and longer than wide ie, more like a penn reel than a fly rod reel. i've made a prototype, and it seems to work pretty well.
i used 1.5mm kevlar bands and they are very STRONG and thin also thick enough to not to entangle but can be cut very easily by the rocks, if you will hunt in open water i can heavily recommend them to you...
thanks murat. if the reef cuts them up then i'm going to steer clear of kevlar. what about dyneema? its also pretty thin (1.5), but it seems like it may be too stiff. is that a problem?
i've heard from a friend who dives with a reel that 30m is standard, so i'm going for that length, unless there are some problems, so if there are, please voice them asap.thanks
i don't know how dynema will perform i tried the line in the picture...
Last edited:
thanks for going to this much effort murat, so what you are saying is i must just catch a few garden snakes and i'm set :)

another question i have is the line guide. is it worth it? dont you guide the line with your fingers when winding up anyway?
the line quide will help the line pay out of the reel when a fish is on the run as well as help you reel the line in and keep everything organized
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!

Last edited:
AAHHH. posted a long one and lost it.


I dont think you design will work - 2 reels, different spinning speeds, big mess etc.

instead use 1 wire (pref cable) but shape the blade pieces to interlock from any angle. put spacers on wire to catch blade pieces.

ask shadowkiller- he knows
btw guys, i made a reel. took me about 1/2 a day. butt ugly though. will post some pics when its prettier
Thanks for the replies, and sorry for hijacking someone else's thread here....I had meant to start a new one.

As to the two reel thing - I meant one reel with two spools, they would both turn at the same speed and with the same spinning mechanism. I just figured having all 4 wires wound onto one spool would be too messy, and thought 4 spools would be a bit overboard... seems to me that any overlaps / potential tangles from the two separate wires would work themselves out; though I could be wrong on that.
what is the wire layout in cross-section? is it four wires in 1 plane or do they from a cross?
DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing


ISSN 1469-865X | Copyright © 1996 - 2024 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Ocean Advocacy and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.