OK I give up
If you drill the last band tab and make the loop extend past the end of the shaft, the swage can hide behind
the end of the shaft. This will cause less turbulence and less directional drag.
Some guy just add more bands.;)
Cheers, Don
Posts by Don Paul
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Makes sense. Maybe we should wax our shafts like Americas Cup racing yachts wax their hulls?
Funny you should say that... after heat treat I have my shafts polished, Twenty years ago I welded some Ti
Comp guns for friend. We found some great teflon tape that we stuck on the barrel.If you start with small changes ie; Ballistic shaped tips, with cleanly faired in wings and low profile thin tabs,
and unkinked mono cleanly swedged to hide behind the shaft, the small changes add up.I know you guys want pics but my EX ended up with my new digital cam.
Cheers, Don -
I always wondered why Riffes always had such big loops....
Jay has been coached for many years, guess where the pin/ line shaft hold down idea came from ?.;)
Don -
Found this mono wheel at bass pro shops made for mono leaders. It was $1.99, 6.5 inches diameter.
Has holes at 12, 3, 6, and 9 o'clock with slits that allow the shark fins to go through and a tight squeeze if used on the flopper side. I have 15ft of line in it but it can easily hold 2 wraps.
I use the same ones, I even store my shafts this way until the weekend diving begins.
Hey while I have you on the phone.
If you make you mono loop longer as to tuck the swage behind the end of the shaft you'll get more laminar
flow. Did you know the mat camo finish on the P51 killed a small percentage of top speed ?
Cheers, Don -
Welcome and THANK YOU for your service mate,
There's a lot of good freedive clubs up there, what is the general area you will be diving?
Cheers, Don Paul -
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yeah friend, I have been flying in the face of clean-shaven divers from the first day.
beards are fine, it is the moustache that gets you...a bit of vasaline will help the mask seal well on even the hairiest lip
Hey, I can see spearing that fish in your avatar... but why are you yelling at it?
;)
another thing that works on a stach is dry suit zipper wax.
Cheers, Don -
R.I.P. brother, my prayers to family and friends.:(
Don -
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My bad, but it doesn't change my overall question.
What I'm trying to get at is whether the diameter of the object being pushed through the water has the bigger impact on shaft speed, etc. or if the weight of the object has the bigger impact.
Stated another way, does the diameter of the tip dictate the shaft speed? If so, using a big diameter tip is a huge mistake in most applications. You might as well be shooting a 3/8" shaft if you use a big slip tip.
To be clear, I'm guessing at this. I would love to know some of the results of what the guys who measured shaft speeds came up with.
Mass is a good thing once you get it moving, a 3/8 shaft powered by 5 hi modulus bands can do a lot of
work. If one launches a Ti shaft greater than 15' you will find impact energy values drop off quickly.Seawater has a density about 900 times greater than air, yes using a tip with poor hydrodynamic profile
will have a large effect on speed on a light shaft.Off to work. Don
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Here are a couple progress shots of a gun I'm working on for a friend.
I'm happy with this new way (for me) of making muzzles where the stock gets wrapped with multiple layers of carbon fiber to build up a super strong cross section which allows for individual band holes with band change slots. I also like the look of carbon all the way to the front.
Great looking gun, very nice cross section. You are a master with the CF
Someday I envision you claying a tube with cocked bands to produce a CF masterpiece with faired in
hydrodynamic power bands that hardly touch the barrel. I love your work.
Cheers, Don -
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Don, I would love to know about the results that you guys came up with in your testing. I assume that you looked at shaft velocity with different diameters.
What about the impact of a larger diameter tip on the speed of a shaft? Does the mass of the shaft or the diameter of the tip (the amount of water which must be moved) have a bigger impact?
What factors did you find to be the most important in achieving guns with the best accuracy in terms of handle height, limit of power vs. gun weight, band slot height, etc?
Impact of enclosed track?
The list goes on and on. Bottom line anything that you can share would be greatly appreciated.
Chad
Hi Chad, I type really slow as I have a broken R hand. I'll share some things but give me some time.
I have a lot of very close friends in the gun building industry and alot of what I have learned is in the
personal guns I build for myself. I'll try to get my scanner on line next week most, of my images are pre-digital.
Gun are a little like religion, many different beliefs to the chosen path.
All the Best, Don -
Dan, it's called spline cycle, it about selecting the correct arrow spline for the wt of the bow. The arrow
bends around the noch and eventually go's into straight flight.
Cheers, Don -
I wonder if anyone has ever setup a high speed (super slow motion) camera underwater. It sure would be nice to be able to see what is happening during the firing of a speargun. When watching an arrow shot from a bow is super slow motion, I was stunned at how much the arrow was bent. I wouldn't be surprised to see that there are things going on that we didn't fully expect - especially with "high power" guns.
Jeff, if you want to come over sometime soon, we could take some video that will at least show whether or not the front of our guns are kicking up during the shot. One of us can film the side of the gun while the other shoots at the target. I have a new HD underwater video camera which might capture some decent data. You need to pull the trigger on the hybrid don't you?
I have lots of pool tests shot on Hi 8 and 8mm film but I would need to get permission to post on the
web. I used to use a spring scale and blue grease to measure shaft energy at the end of the wire rope.
later on some guys were using mono with precision black marks and a bar code reader feeding a lap top.This
gave good data on shaft velocity. Shite :0:0 this is sounding too much like work.... now where is that bikini
thread? FWIW my bands are on the same axis of symmetry as the thumb and index finger of my
gun handle.
Cheers, Don -
Your handwriting says your a Doctor not a Engineer.
My gun is as heavy as a crow bar, it helps me get down fast and muzzle flip is not an issue.
Hey I hope you know I just joking about the handwriting.
Cheers, Don Paul -
haha lunkerbuster is guilty of a few of those
welcome.. i didnt know there were casual cold water snorkelers out there
Their called Canadian.
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Welcome mate, there are a great bunch of guys here.
Don Paul -
Locally, speargun (pistola) is feminine by the way..:)
Not the John Riffe I knew;)
Don -
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I really enjoyed that.
I know Jean Tapu (1967 World Champion ) from Tahiti, he is a very deep diver, here he is now.
Don Paul
