SpudFiles

How does it compare to electronic firing?

I'm thinking it should be pretty much the same thing, but a lot simpler

Putting something together to test the valve

Finally figured out how to make a slide show

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Trying to organise my commonly used tools a bit, found some old aluminium channel to use as a stand. This is my metric nut spinners, 5.5, 7, 8 & 10, metric x7 Hex key driver, 1/4" ratchet (25 year old Snap On and still all original) with Standard and metric sockets.

Those 1/4" drive Snap On sets are just the best to work with hands down!

jrrdw wrote:Those 1/4" drive Snap On sets are just the best to work with hands down!

I have a Wera 1/4" ratchet at work and it is pretty sweet as well
And another stand for my T handle metric keys and some wrenches

I finally figured out the ideal way to make darts for my blowgun! I tested out how moving the center of mass would affect long range performance and I've found that grinding the dart so that the center of mass is just behind the middle of its length makes for a very nice long range penetrator. Here's a shot at an empty can from approximately 40 feet away, it still had enough force to pin the can to the fence!
For a simple blowgun made out of nothing other than a 4 foot length of 1/2" sch. 80 PVC, that's quite nice performance.
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As you can see from the marks on the fence, it took me several attempts to hit it from that distance. I'm not sure if that's my lack of practice, the sloppy cone on the dart, or a combination of both. Either way, the grouping was still decent.

Cthulhu wrote:I finally figured out the ideal way to make darts for my blowgun! I tested out how moving the center of mass would affect long range performance and I've found that grinding the dart so that the center of mass is just behind the middle of its length makes for a very nice long range penetrator.

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Here's a shot at an empty can from approximately 40 feet away, it still had enough force to pin the can to the fence!
For a simple blowgun made out of nothing other than a 4 foot length of 1/2" sch. 80 PVC, that's quite nice performance.
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As you can see from the marks on the fence, it took me several attempts to hit it from that distance. I'm not sure if that's my lack of practice, the sloppy cone on the dart, or a combination of both. Either way, the grouping was still decent.

It looks excellent shooting ... I like it! I love blowguns and crossbows. Try to buff the darts. Here I leave a video of how to do it, in case you are interested
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hectmarr wrote: It looks excellent shooting ... I like it! I love blowguns and crossbows. Try to buff the darts. Here I leave a video of how to do it, in case you are interested
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Thanks!
I really should spend more time polishing and cleaning my darts before tempering them, it's a shame I'm so lazy

I finally got around to testing fletching on darts.
I made some quick and experimental (AKA sloppy) helical fletching onto a barbed dart I lathed on an electric drill.
Turns out (pun intended), that the dart actually does rotate as it flies! I'm not sure if this increases accuracy at all, but my current tests have shown that it does indeed rotate clockwise as intended.

Sadly the fletching is easily crumpled and torn, so I'll be looking for a better material for it soon.

The best dart fletching design I've come up with so far is a three finned dart with angled leading edges. It's intended more for air cannons than blowguns, but it's possible it might be of some inspiration to you.

I don't seem to have a picture of the current version, but this is an older prototype with four non-angled fins that gives an idea of the rough design. (Naturally, this design needs some form of sabot behind it to seal the barrel).

The angling of the leading edges on the fins isn't strictly about trying to improve accuracy or stability (although I think it helps, but I've never thoroughly tested it), but about reducing the drag on the leading edge.
Firstly, it's easier to angle it one way or the other rather than trying to create one straight edge in the centre.
Secondly, once the dart is set spinning, the leading edge has a lower relative flow velocity over it, reducing drag further.

The swap to three fins had a similar motivation - reducing drag. It reduces the skin surface of the dart considerably - skin drag (rather than form drag) seems to be one of the most significant contributors to the drag on this design.

Mind you, I'm not sure I'll ever use these in a context where that would matter. As far as I can tell, these would probably preserve about ~90% of their velocity out to 400m, but there's nowhere I can think of where I have a hope of actually trying to shoot them that far.

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One of my creations made it to the Taofledermaus poster