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Old 04-03-2020, 03:44 AM   #91
Satdiver
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Re: Made a 145cm inverter, 10mm shaft

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Originally Posted by 2fishin2 View Post
I hate Hunt shafts so much I have taken them off the guns that came with them and replaced them with Dean's.

Floppers on them worst I have ever encountered....

I dont understand why people still use them (Alemani)

You mean Dean's Koutras from Addiction shafts?
Addiction Shafts do look very well made. I definitely buy some to try when ever I get back to work.

Last edited by Satdiver; 04-04-2020 at 01:10 AM.
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Old 04-03-2020, 12:26 PM   #92
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Re: Made a 145cm inverter, 10mm shaft

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I hate Hunt shafts so much I have taken them off the guns that came with them and replaced them with Dean's.

Floppers on them worst I have ever encountered....

I dont understand why people still use them (Alemani)
who is dean's ?
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Old 04-03-2020, 01:54 PM   #93
popgun pete
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Re: Made a 145cm inverter, 10mm shaft

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who is dean's ?
http://www.addictionspears.com/
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Old 04-03-2020, 02:04 PM   #94
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Re: Made a 145cm inverter, 10mm shaft

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Originally Posted by Satdiver View Post
I had both your older models, 100 and 110. The 100 is drifting around Indonesian waters somewhere.
Yes, I found both guns extremely accurate and the quality of your gun builds are amazing.
Who knows, maybe someone was lucky and found it.

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Do you think the kicker band is working in conjunction with the bottom inverter bands?

My thinking is the kicker band is faster than the inverter bands and the inverter and not working in conjunction with the inverter bands.
I did a lot of testing with a kicker band and without a kicker on my Alemanni 135 Vela.
What I found, if you load the inverter line to the very rear shark fin I had more shaft speed, rather than using a kicker band loaded to the rear shark fin and the inverter line to loaded 50mm to the next shark fin.
The gun has 2 x 20mm bands and 3 sets of 19mm bands. Its a extra 400mm of band stretch loading the inverter line to the rear.
Alemania recommended to me not to use the kicker band on his Vela.
You have 4 band pairs, so maybe, but just maybe it works fine without kicker band. Kicker band do just as it's said. It kicks shaft and compensate slower start of bands over moveable pulleys. When kicker band make initial move other bands accelerate shaft to final speed. Some manufacturers like thicker bands on lower streching factor, but that way pretension is almost zero. Not just on one band pair which goes over rear pulleys.
Personally I think better solution is using softer bands or bands with smaller OD. That gives enough pretension, and shaft accelerate all the way moving to the head of the gun.
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Old 04-03-2020, 02:26 PM   #95
popgun pete
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Re: Made a 145cm inverter, 10mm shaft

You get more stretch travel for the same force on thinner bands. Bands can be thought of like an onion cut in cross section with rubber tubes of increasing diameter stacked on each other. More rubber in the cross-section then it is harder to stretch it out.

The ratio of the cross-sections of 16 mm and 14 mm bands is (16/14)^2 which equals 1.306, therefore for the same elongation it should take 30% more effort to pull 16 mm bands compared to 14 mm bands, everything else being equal. If the bands have a central bore hole then we need to adjust the cross-sectional areas for the missing material represented by the hole, thus bands of the same outer diameter but with a smaller central hole will have a greater cross-section of rubber and will need more effort to pull them to a certain elongation. Conversely a larger central hole will make them easier to pull.

Last edited by popgun pete; 04-03-2020 at 06:47 PM. Reason: extra comment
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Old 04-04-2020, 12:06 AM   #96
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Re: Made a 145cm inverter, 10mm shaft

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Old 04-04-2020, 01:27 AM   #97
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Re: Made a 145cm inverter, 10mm shaft

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Who knows, maybe someone was lucky and found it.

Yes some lucky local fisherman most likely of found it for sure. Was my mate young boy shot a fish with a brake away set up and got a bit excited and forgot about the gun.
I did like this gun, the balance was perfect.

You have 4 band pairs, so maybe, but just maybe it works fine without kicker band. Kicker band do just as it's said. It kicks shaft and compensate slower start of bands over moveable pulleys. When kicker band make initial move other bands accelerate shaft to final speed. Some manufacturers like thicker bands on lower streching factor, but that way pretension is almost zero. Not just on one band pair which goes over rear pulleys.
Personally I think better solution is using softer bands or bands with smaller OD. That gives enough pretension, and shaft accelerate all the way moving to the head of the gun.
Yes some lucky local fisherman most likely of found it for sure. Was my mate young boy shot a fish with a brake away set up and got a bit excited and forgot about the gun.
I did like this gun, the balance was perfect.

Your band setup up on your gun definitely works very well, can see that quite clearly with the video you shared.
I think there would be more recoil with smaller I/D bands on my gun, but would be a interesting test to see the difference.
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Old 08-30-2020, 04:34 AM   #98
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Re: Made a 145cm inverter, 10mm shaft

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Hi Jon, Yes, I think you had left Bali when I moved there. I'm in Aberdeen Scotland, I few here just before the flights stopped. I hear Bali is super quiet.

This gun is very accurate, even though the is shaft is lifting. I believe this is because the gun has zero flex. The shaft is pushed back into the track as the wishbone leaves the stopper tube and leaves the gun flat. I would like to try a 11mm shaft but no idea where to buy one.
When you shoot this gun, your first thoughts is. it doesn't feel like it has much power as there is very little recoil from this gun. The recoil is smooth, if that makes sense.
I will try and find better side view video, I know in that video it looks like the shaft is down a bit, but the shaft is very flat in flight.

I have made some video's testing 3 & 4 band classic guns, theses video's showed both set ups had shaft lift. I believe most powerful classic guns will have shaft lift. But yet to prove this theory. I'm sure Majd could correct me on this theory with all the testing Majd has done.

Andre did make a inclosed track roller gun, the shaft was splitting the wood where the shaft was exiting the end of the inclosed track. Andre doesn't make inclose track roller & inverter guns anymore.
My thinking with a inclose track, is there to much force been pushed up and which will course poor performance, but I have never tested a inclose track gun.

The gun is quite big size to float the heavy shaft and the three & half raps 1.6mm cable (total length 11.2 meters). I will attach dimensions of the gun.
I have just taken the measurements of the "vela"
apart from your head which is 5mm wider your measurements are almost identical to alemanni for 10 cm more draw, it is remarkable work.

have you had success?
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Old 08-30-2020, 09:01 AM   #99
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Re: Made a 145cm inverter, 10mm shaft

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Hi Pete,
I have been using inverter & roller spearguns for many years now. I can't think of any problems I have had, other than the wishbone slipping. I now do a double sheet bend to stop the slipping with the heavy load on the wishbone.
These guns do look complicated and slow to load. But after you use one, they are not so complicated and as fast to load as classic gun. Easer for the first loading as the pulleys halve the load.

If you look at the side view in the video of shooting this gun, you can see the shaft lifting about 30mm as soon as the shaft leaves the mechanism. Also the 10mm shaft is bent under the force of the bands. As the wishbone gets towards the stopper tube the shaft is pushed back down to the track and leaves the gun flat. The rubbers are powering the shaft all the way to the stopper tube.
All the inverter and roller spearguns I have tested, the shaft will lift as soon as it leaves the mechanism.
I made the front rollers as low as I could, trying to stop the shaft lifting. but doesn't seem a problem from the testing I have done.

You are correct with the roller size, bigger rollers are better for the bands.
I made my back rollers size to keep the 20mm rubber in the routered groves on the top of the gun to help with tracking the gun.The other thing is the rubber should be clear of the gun body by a couple of millimetres, but not to much as it will course the gun to make that shuddering noise when tracking. The gun will lose performance if the bands are touching the wood when the gun is fired.

You don't use small cord in the bands for inverter gun bands. Only use cord in bands going through the front rollers for double and mono roller guns.
Great gun!!!! which diameter do you think the roller must be?
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Old 08-30-2020, 10:23 AM   #100
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Re: Made a 145cm inverter, 10mm shaft

wow, nice gun, I'm still using 7.5 on my four band 150... 10 mm!!! I wouldn't even know where to get those lol.
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Old 08-30-2020, 01:05 PM   #101
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Re: Made a 145cm inverter, 10mm shaft

Quote:
Originally Posted by 2fishin2 View Post
I hate Hunt shafts so much I have taken them off the guns that came with them and replaced them with Dean's.

Floppers on them worst I have ever encountered....

I dont understand why people still use them (Alemani)
In fact, the best american made shaftAre the Dean Koutras and Mori, The hunt ones that I see at their website, shows poor work and bad weld at the shark fins
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Old 09-01-2020, 12:57 AM   #102
Satdiver
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Re: Made a 145cm inverter, 10mm shaft

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Great gun!!!! which diameter do you think the roller must be?
Hi Memosub, I made my back rollers 27mm, measured in the center of the roller. I router groves in gun body so the bands are partly in the grove to stop the bands shuddering when tracking.
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Old 11-13-2020, 12:40 AM   #103
fredfoes
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Re: Made a 145cm inverter, 10mm shaft

Hello

does your speargun float with the spear ?
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Old 11-14-2020, 01:40 AM   #104
Satdiver
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Re: Made a 145cm inverter, 10mm shaft

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Hello

does your speargun float with the spear ?
Hi Fred, it is balanced with a 10mm shaft. Sinks very slowly. Without a shaft the gun floats.
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Old 11-14-2020, 05:41 AM   #105
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Re: Made a 145cm inverter, 10mm shaft

Merci beaucoup

Last edited by fredfoes; 11-18-2020 at 10:39 PM.
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