Funting with a Polespear

I have recently added a new hobby to my life.

The timing couldn’t be worse, really.

I already have a 2 year-old daughter, a baby boy due any day, a full time job, a wife, and a large number of unfinished projects, but now I have to accommodate the compulsive urge to kill fish with pointy objects.

I grew up in the Seattle, Washington area and always enjoyed fishing, but somehow, since moving to San Diego 10 years ago, I haven’t found to time to go fishing.

I guess the problem is that I’m pretty busy with many other areas of my life, and it’s hard to justify spending a few hours on a weekend sitting and  waiting for a fish to commit seppuku with a hook on a string.

Then I discovered spearfishing. Spearfishing is different, it’s like snorkeling with a purpose. It’s not just sitting around waiting, or even just swimming around and looking, it is hunting. Fish hunting. Funting. 

I’ve gone twice now, and I’m mildly obsessed.

As is the case with most of my hobbies, it’s not enough for me to just participate in spearfishing, I have to improve on it, customize it, make it better, or at least make it my own.

To this end I modified the tried and true polespear to add a trigger mechanism.

The polespear design is simple: it’s a spear with a rubber band attached to the base. To kill a fish with it, you hook the rubber band with your thumb, stretch the band toward the tip of the spear, and then grab the spear shaft near the tip in order to hold the band under tension. Then you point it at a fish nearby and loosen your grip, allowing the spear to lurch forward; ideally impaling the fish in the process.

The idea to modify this weapon came to me when my friend complained about his hand getting tired from swimming around holding the polespear cocked and ready to shoot. 

I decided that the polespear would be better if it had a trigger, and came up with this design:
PoleSpear

Then I built it…

First I took a piece of stainless steel and shaped it into a snug-fitting collar that I attached near the tip of the spear with a spring pin.
PolespearMod

Then I glued together a few pieces of wood (something like teak that I had laying around from old patio furniture), drilled a hole through it (slightly large than the spear shaft), cut it to and arbitrary shape using the bandsaw and affixed a little latch (also made from stainless steel) to hook onto the collar.
PolespearMod

To keep the spear from traveling too far, I added a collar at the base with some soft rubber tubing to act as a cushion when the spear is stopped (I think the piece of rubber is an in-sink garbage disposal adapter).
PolespearMod

To use the spear, I hook the rubber band through the wooden handle, and then slide the handle up the spear till it latches onto the collar at the tip.
PolespearMod

PolespearMod

And then I fired it at a piece of plywood.
PolespearMod

I will hopefully get to use this to kill a fish this weekend, if my son doesn’t disrupt my plans by being born.

Update: I used this over the weekend and probably killed a few fish. I say “probably” because I didn’t actually “catch” any fish.

The rubber band I used is the standard light-duty polespear band, and the added weight/drag of the collar seems to have slowed the spear down just enough to really damage a fish but not actually skewer it. The result is that there are an number of disabled fish hobbling around the waters off the San Diego coast, if they are lucky. The unlucky ones died slowly Saturday morning, trying to figure out why I feebly stabbed them with a dull piece of metal.

The trigger itself worked beautifully, and I’ve ordered a more powerful band that should many little fish fatherless when I next enter the waters.

Lathe Boring Bar Holder

I find boring bars exciting.

I have a boring head for my milling machine, which is excellent (indispensable) for milling holes to a certain diameter in square stock. But for round stock in my lathe I’ve been messing around with various cutters with mixed results while trying to cut the inner diameter of various projects.

Boring bars are the correct tool for the job on a lathe, but I don’t have any. Even if I did, I don’t have a holder.

I decided to rectify this situation by making a holder that would accept the cutters from my boring head set.

When I made my quick-change tool post, I milled a dovetail into a large block of steel. The idea is that I can cut off chunks as needed to make various tool holders without having to mill a new dovetail.

I sliced off a chunk with my portable bandsaw, cleaned up the shavings, and then milled it down to a more appropriate size.
Boring bar holder for lathe
I drilled a starter hole  in one end and through the full length of the workpiece.

Then I used my boring head to bring the diameter to fit the boring bars’ 1/2-inch shanks snugly.
Boring bar holder for lathe
Boring bar holder for lathe

In order to check by progress while boring the hole, I had to move the workpiece out from under the cutter and fit some calipers into the hole. My DRO proved very helpful for this: I could set the axis to 0, move the table to get the workpiece to a measurable location, and then  move it back till the DRO read 0 again. It perfectly relocated the hole under the boring head every time.
Boring bar holder for lathe
Boring bar holder for lathe
Boring bar holder for lathe
Boring bar holder for lathe

Once I had bored out the hole to the proper depth and diameter,
Boring bar holder for lathe

I set the workpiece on its side and drilled 2 holes through to the 1/2-inch hole, which I then tapped out with 1/4-20  threads for set screws (i once again use the DRO to relocate the holes after changing the drill bit out for the thread tap)
IMAG1Boring bar holder for lathe069
Boring bar holder for lathe
Boring bar holder for lathe

In order to tap the threads perfectly straight, I like to lock the tap in the drill chuck, and then use my lathe chuck handle to turn the chuck manually.
Done!
Boring bar holder for lathe
Boring bar holder for lathe

I slapped the new boring bar holder on my lathe and bored out the inside of a couple of my lathe feed gears as an inaugural project. The boring bar performed perfectly in its new holder.
Boring bar holder for lathe

I win.