The Deeperblue.net Gun Building Extravaganza - pre poll gun shape

[foxfish]

Hi deeperthanblu thanks for your input, the gun has an enclosed track & therefore will fire a shark fin spear, do you still think your sujestions apply?

[deeperthanblu]

Originally Posted by foxfish

Hi deeperthanblu thanks for your input, the gun has an enclosed track & therefore will fire a shark fin spear, do you still think your sujestions apply?

Yes, if you have two or more bands on the shark fins, you put the short one on first. The second one comes back over the first and is placed on the farther shark fin. If the speargun is wide there, it will tend to sit on top of the first band as it narrows to wrap around the fin. Having a narrow barrel there allows the bands to wrap down a bit lower. It also makes it easier for you to remove your fingers from under the bands after nocking. Third and fourth bands make it worse, as they all compete for that same space next to the spear shaft.

[Pastor]

So what shape is this gun going to be? No wonder things aren't being done if nothing is being discussed!

[foxfish]

This does seem to be the most difficult question yet! No we dont want this to be a clone however the gun already have some strong & unusual features & the tried & tested shapes will most likely be the best? I find it difficult to draw any ideas I might have as I would normally have a design in my head but to be honest I would be happy with a streamlined & slim shape but with enough wood to allow nice balance.
I have had problems with the last few wood gun I have built because there has not been enough buoyancy near the muzzle.

[glowworm]

If someone could sketch some shapes/designs and put them up on this thread it would help those who have no gun building knowledge.

[glowworm]

Could there be some pictures of possible gun shapes be put up with the poll?

[Spaniard]

Good idea Glowworm - as a no-idea engineer/designer it would help to see available options! Mmmmmmm pretty it will be.

[foxfish]

Spaghetti made this very logical post - makes sense to me -

I'd like it to be ellyptical, with tiny muzzle wings.
If I'm not mistaken we're talking of a single band 90cm euro bandgun, right?
Well if so a single band 90 is mainly a gun for agguato, the peek-a-boo hunting to fish suddenly appearing from behind a boulder, or briefly side spotted as they're leaping into a bush of weed.
This is why I think we should not make a "bulky" gun: it's a single band 90, not the gun you customarily use for long powerful shots. The gun for me has to be very manouverable, very fast tracking, and an ellyptical shape will cut the water better than any other shape.
As for wings, on a relatively slim gun the tiny muzzle wings will help to prevent muzzle whip from recoil, especially if the user decides to "pepper" the gun with stronger bands.
Just my input: I think it makes sense.
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[mishu1984]

hmmm, single 90 with enclosed track, elyptical with wings. sounds a lot like my picasso 110 except for the track part, mine is open track.
if you can, play around with some software to figure out the optimum angle of the wings to reduce drag. im sure some autocad whizz outhere will be able to run a simulation for you.
you might want to make it a circular band instead of a screw in, that way you can reduce drag at the muzzle while swinging the gun around, and make the slots in the stock itself.
im assuming you will be using a 6mm shaft since you want fast shoots?

[ILDiver]

If it's going to be elliptical and it tapers down. Here is a style of wing I'd like!


I still like this idea of tying the bands to the muzzle too. Maybe through the muzzle to mace a sort of tied circular band. With the smaller hole you could get the center line of the band more accurately in line with the spear.

[glowworm]

Do the wings have to be that big?

The comments made by Foxfish make sense.The gun sounds like it will be sweet.

[foxfish]

Personally I don't see the need for any wings but if there were to be any, they couldn't possibly be that big!!
So a thin profile & elliptical shape sounds good?

[Pastor]

Mass is more important than wings, they always seem like an after thought to a flawed design, to try and add to a lightweight gun or a way of saving money on wood before the gun is shaped. Put enough mass in it and it don't need anything else, what was it, a 6.5mm spear? What a 90cm euro gun needs is to be as aquadynamic as possible - as little resistance near the muzzle as possible but still enough bulk to absorb as much energy as possible (sound and recoil)

[ILDiver]

I just saw the style and liked it. Kind of like a manta ray. The pic is a bigger gun too.

[foxfish]

My favorite gun shape that I have produced was this one, obviously not made from wood but I like the smooth lines.