2 Ways for a DIY Polespear

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Introduction: 2 Ways for a DIY Polespear

About: Living on a small island makes you very adaptable and inventive. so repairing-, DIY- and custumization-projects are always around! unless you want or like to spent boatloads on importing... I have a hundred ...

After my first instructable about making a DIY zookeeper, it only makes sense I also do one about making your own spear to actually being able to catch them devilfish!

This spear is based on the JBL polespear but is a bit heavier and so, packs a bigger punch on initial impact.

The actual speartip is a storebought item. I tried making one a couple times, but they just didn’t hold up over time (except a single barred one, shown in a picture and in the ‘alternatives’ later).

Because the easy-way would be a very short ‘ible, I’ll be showing you 3 builds;

Okay, its 2 ways and 1 failed experiment…

1 with scrounged-around-the-house materials. But I understand that most people are not as hoarder-ish as I am, so I’ll also show you how to build one using storebought materials.

The sling is the same for any of the builds, so that section is placed after the spear-build-options.

Tips and alternatives also given at the end.

Step 1: Buildoption 1 - Storebought Material

Tools and Hardware:

Tools;

- Iron saw/ hack saw

- Threadlocker (optional but recommended)

- Small rounded file

- Pliers with hollow grip

- Measuring tape (optional but recommended)

- Permanent marker/ sharpy (optional but recommended)

Hardware;

- Spearhead with 6mm female thread ($20,- to $30,- on amazon)

- 1m aluminum tube (10mm outside diameter)

- 1m threaded rod 6mm (I’d advise on Stainless steel)

- 2 stainless steel split washers/ split lock washers/ spring washers

- 1 6mm stainless steel ringnut/ eyenut/ lifting eye nut


Shaft and rod;

After you take all labels and residue off your hardware (you might have to use some nail-polish-remover or such). We’ll start off with securing the eyenut onto one side of the rod. If you can get them in lock-nut-style, use them! Otherwise use a little threadlock to make sure it doesn’t come off again! Give the threadlock at least 15 minutes to cure, 24 hours for best result.

Put one of the split washers onto your rod and lay your tube next to it, up against the split washer. If your rod is exactly as long as your tube, or longer, you need to cut some off. To find out exactly how much you need to cut, screw on your speartip aswell (don’t forget the second split washer at the side of the speartip!)

If you look at the picture you can see I need to cut my tube down several cm’s. The thing to keep in mind here is to leave just enough space (rod) for the speartip to be screwed on! Leave the pipe about 3mm longer as opposed to an exact fit, to ensure you tighten your tube in between the eyenut and speartip! In the picture the left marking is an exact fit, the right one given 3mm extra length.

After cutting your tube to the correct size it’s a matter of putting together; from bottom to top; eyenut (secured with threadlocker), splitwasher, tube, splitwasher, speartip.

It’s that easy!

Now, I know where I need to put on some extra grip on the tube when considering the quality of your sling, the length of your sling and the amount of force I use to cock and shoot my spear; I have a cocked grip at about 65cm from the bottom.

So from the bottom I measure and mark off at 55cm and 75cm. I wrap this solidly with sportstape to ensure a good grip when shooting bigger fish. For small fish I tend to grip just below the tape.

Step 2: Buildoption 2 - Scrounged-around-the-house Materials

Tools and Hardware:

Tools;

- Electric drill with 1/8” and ¼” drillbit

- Iron saw/ hack saw

- Hammer

- Small rounded file

- Measuring tape

- Permanent marker/ sharpy

Hardware;

- Spearhead with 6mm female thread ($20,- to $30,- on amazon)

- 1m aluminum tube (found my old blowgun in a corner)

- 1m threaded rod 6mm (I’d advise on stainless steel)

- 1x 6mm locknut

- 1x 6mm nut

- 1x 6mm acornnut + fitting bolt (missing in picture below)

- Sportstape (missing in picture below)

Shaft and rod;

When I was looking around for usable stuff for this instructable I was very happy to find an old blowgun of mine sitting in the corner collecting dust. So to give it a new life and a couple more years of useful service, I decided to re-use this aluminum tube for a polespear.

The great part of this tube is that it has a widened end on one of its sides, and the normal side is just big enough to cover the narrower part of the speartip! This will be very useful for putting-together.

A downside is that it’s made up out of 2 parts.

This was a lucky find and I don’t expect a lot of people will find this exact kind of tube.

Start off by securing the 6mm locknut on one end of the threaded rod. My threaded rod is bent at the end, so I’ll have to screw a nut on from the other side. It won’t cause any trouble though.

Take the aluminum tube with the enlarged bottom, now with an 6mm acornnut and a fitting bolt I’ll try to hammer it in the tube. Only enough so the indentations show of a 6-sided-nut inside the tube.

Scoot the aluminum tube over the rod with the widened part going over the locknut. Now you’ll have to take a nut and screw it all the way onto the tube (I use my electric drill to speed things along here, put your nut on the thread and the threaded rod into your electric drill. Don’t fasten too tight or you will damage the threads! Put electric drill in reverse and hold on to the nut as you slowly start rotating your drill). Before you hit the tube, jam the (hammered) indentations onto your nut and use the tube as a handle to fully tighten the tube in between the nuts!

You could put some indentations in the other tube-part as well, but I figured it wouldn’t make a big difference, so I decided to leave it. Scoot your other tube-part over the threaded rod now aswell.

Now either your tube or your rod will be sticking out further than the other, so one of both needs to be cut to length. If you look at the picture you can see I need to cut my rod down several cm’s. The thing to keep in mind here is to leave just enough space (rod) for the speartip to be screwed on! I cut my rod as long as my tube is.

So, in steps, mark your rod, remove top tube, screw on a nut (read tips), saw rod to length, file for neat end, unscrew nut, replace top tube, screw sprearhead on!

Now with your 1/8” drillbit, plunge a hole near the end of the pipe and widen that hole now with an ¼” drillbit. File the hole to make sure there are no more burrs in or around the hole (this will weaken or damage your rope).

Cover the connecting pieces with a bit of electrical tape for an clean look and a bit thickness for grip (a more solid grip on the fairly thin tube when cocked and ready to shoot). I wrap sportstape from 55cm to 75cm measured from the bottom.

Step 3: Buildoption 2½ - Storebought Materials; FAILED

Shaft and rod;

I wanted to make a back-end, the same style as the one described in the scrounged-around-the-house chapter… … next is a read-for-fun kinda documentation… so you know you don’t have to try.

"We’ll start with a small experiment. I going to try to hammer a 6mm nut into the backside of the tube. It needs to sit in at least 1cm deep, so… I think my chances are reasonable…

Inspired by the tube I found in the scrounged-around-the-house build-option.

I’ll heat up the tube, put a acornnut attached to a fitting hexbolt on the backend, put your tube on a block of wood and try to hammer it in gently (or barbarically, which ever works!). It needs to sit in the tube fairly straight for the rod to pass through."

"Well… the flush-with-the-tube part is possible, as the picture shows…"

"I’ll admit I was hammering pretty savagely to get it in and I used an acornnut (their rounded up all the way into hexnut-shape) on a long M6-bolt to have a handle. Worked it all the way in and then wiggled it out making place for a 6mm locknut. Heavily mangled but I got it fitting…

So go slower, take your time, ease your way in… and even though I made it as far as to where the transition is to a hexnutshape, hammering real slow and gently, heating it up gently and not blackening the end, it also bend the tube far enough not to fit anymore."

I’m sure if you take a 10mm (inner diam.) tube this would be possible! The hardwarestores were out at the moment of purchase… Islands…

Step 4: Sling

Tools and Hardware:

Tools;

- Screwdriver (+)

- Scissors

- Measuring tape

Hardware;

- 50cm rubber tubing, surgical grade (slingshot-type/ theraband/ harpoonsling)

- 40cm paracord

- 4 small tierips/ zipties

Sling;

For the sling you need about 50cm of surgical grade rubber tubing (surgical grade for its stretchyness and longevity). Theraband (black or gold) would be a good alternative, but as with a lot of stuff on small islands, I can’t get that here… I do think the round tubing is more water-dynamic (less drag through the water).

Start with knotting off both ends of your 40cm piece of paracord using a figure-8 knot. Take a screwdriver (or other pointy, not sharp, item) and work the knots about 2,5cm into the tubing on both ends.

Secure with 2 small zipties on either side and cut off access straps. Try to get the ziptie-‘heads’ pointing in the same direction, on the outside of the tubing (so exactly opposite side of where I tightened them! ). Sometimes they are positioned in a way that it will scratch the inside of your arm when shooting, try to avoid this by adjusting the way you secure your sling onto the spear.

Double up the paracord (in the middle) and pass it through the hole on the back of your spear. Pass the loop over the end of the spear and pas the rubber tubing through the loop and pull tight.

Step 5: Alternatives and Tips

Alternatives and tips;

- Use stainless steel and aluminum!

- If you, like me, couldn’t get stainless steel rods (I ended up buying a zinc plated one, which WILL rust), you might want to cover the parts of the threaded rod, there where the speartip and nuts screws on, with a 50/50 primer. This way if you need to change anything, it is still completely dismantlable/ replace-able.

- You can also use rope or cord as a grip-feature on a spear (glued in place).

- Make sure there is still a way for water to enter and drain out of the tube. A waterfilled spear shoots better as an airfilled one, so don’t make it airtight (using glue or anything).

- A little epoxy or threadlocker makes for a solid nut-to-thread-connection, just don’t accidentally fill/ airtighten your tube!

- The counterhooks on the speartip are (very) aggressive. So much so that it will take chunks out of your fish or it will damage the funnel of your zookeeper when trying to get the fish off. I suggest (on these spearheads) to grind down or flatten 3 of the 6 counterhooks.

In the picture you can see one of my older spearheads; the outer (3) spikes are counterhook-less! On the new one I hammered the inner 3 counterhooks flat with the help of the sawn-off piece of rod

- Use a solid 12mm rod. Drill a hole 5mm wide, 5cm deep into the top of your rod. Take a 6mm hex bolt (6cm long), grind down the theads just slightly on the 5cm you intend to insert into the rod and hammer in (like frkng Thor himself!). Angle-grind the hex-nut-head off and clean the top up. You could use some epoxy, this wasn’t necessary in my case. Screw on speartip and don’t forget to put a hole in the back for your sling to attach!

OR… use a 15cm long 6mm hex bolt, Thor it in, cut off hexbolt-head, file/ grind the threads off leaving just 1 strip of theads (vertically, 1mm wide to act as ‘counterhooks’) and grind/ file a point to it. No need to spend 30bucks for a speartip! Single barbed spreartip tho.

- When you have to saw your threaded rod, make sure you have a nut on the inside. Screw off after sawing and filing to align the thread again.

- When using a different sling or different length (spear or sling) the 55 -75cm might not match up with your grip. You might want to wait with taping until you can try the sling itself. Stretch the tubing a couple times before simulating a shot, then mark off on both sides of your hand (when holding it cocked) and give it 5cm extra on both sides.

Now you know exactly where to put your tape!

- It might be a bit tricky to get the tube, split washer and speartip to line-up nicely. I use the hollowed/ rounded part of a pliers to squeeze the splitwasher into place.

- Use a 10mm (inside diameter) tube. Or better yet; take measurements from the speartip and find an exact fitting tube!

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    2 Discussions

    Great inventiveness on display! Well done :)

    1 reply