'Mag Track' by Riffe dose it work?

[ferris]

Greetings fellow spearo's and divers!

It has been quite sometime since I last put digital binary to screen so I decided I'd stop the procrastination process today.

'Mag Track' by Riffe is a patent pending invention that Riffe say helps with ease of loading and "free-shafting"! I love it when companies use new terms created for the use of up selling there product (free-shafting)http://forums.deeperblue.com/images/smilies/new/friday.gif

So they have put an magnetic track in the speargun, spears are metal magnets attract metal makes sense right? Not quite!

I am in to science a lot and and so I love to find out the physics behind new inventions or in this case utilising an old concept and transferring it to a different machine.

So let me explain why it is my opinion and mine alone that Riffe's 'Mag Track' is actually a making a negative not a positive to it's already perfect spearguns!

I must admit I don't own a Riffe, but I sure would love a euro minus the
'Mag Track' though! Those spearguns are one of the most beautiful looking spearguns on the market and in no way do I want to sound as if I am rubbishing Riffe I am not and am in no way trying or even wanting you to stop buying RIFFES QUALITY SPEARGUNS OK.
I am just letting you hear 'my opinion' on why scientifically the 'Mag Track' is of no benefit to you.

#1. Not all metal is magnetic! metals are broken up in to two different types.
Ferrous (magnetic) and non Ferrous (non magnetic).
Iron is magnetic were Gold is not so certain metals will just not have enough physical attraction to a magnet, however it is worth noting that all metals are magnetic it is just that non ferrous metals are just much more stable in there atomic setup then ferrous metals.

Get to the point Ferris!!!!


My point is this true stainless steel is non ferrous therefore as explained above it is non magnetic so it just wont stick to a magnet.
This then makes the idea of a magnet track completely useless for "ease of loading and Free-shafting" as the magnets wont hold the S/S shaft.

You would have to use a low quality S/S shaft which had a greater iron ration in it for this to work. That means you have a weaker and rustable shaft though.

#2 As I explained earlier ' all metals are magnetic it is just that non ferrous metals are just much more stable in there atomic setup then ferrous metals'.
Because of this when any strong magnet is moved over any metal an opposing electromagnetic field is produced. This is called Lenz's law.
What happens is of more importance.
Due to Lenz's law the metal shaft as it is propelled over the magnets of the 'Mag Track' will actually slow it down if it is made from true S/S which is non ferrous.
This makes the shaft's exit speed even slower with a 'Mag Track' then without one.
An note to add would be this; the stronger the magnet the slower the shaft will exit from the gun! This is because the opposing electromagnetic current produced is equal to the strength of the magnets pulling power.

Now if you used a ferrous met shaft it would still slow the shaft down in theory as the shaft has to overcome the attraction of the last magnet however this once again depends on the strength of the magnets the stronger the magnet the more force is needed to overcome the magnetic attraction. It is posable to speed up a ferrous shaft if the magnets become stronger and closer to the shaft as they go along the track but the last magnet will create the force that I mentioned you would have to overcome but as you have elastic bands pulling this should not be a problem. In this case you would not lose any speed but may gain a minute more, but you do need to use a steel only shaft for this to work.


So in all for this system to work you would need to use a non S/S shaft to get any decent effect out of it but keep in mind that this shaft will rust and will be prone to bending and breaking much easier than a Proper S/S one.

I hope this has made sense to somebody and has enlightened the unknowing consumer.

Once again this MY Opinion and Mine alone! I don't represent any other company nor do I wish to rubbish Riffe in anyway as it is belief that Riffe's spearguns are of the finest available in the world! I just disagree with the purpose of there 'Mag Track'


Kind regards to all and feel free to correct me if you think that this information is incorrect in any

Ferris

 

[Unclejake]

The magnet is about the size of the nail on your little finger and it works fine with the Riffe shaft.

If you don't like it you can unscrew the magnet and throw it away

 

[ferris]

So Does that make it just a gimmick then?

I would say yes!
my opinion and point is that it is of no use to the consumer and is just a selling point for hype sake.

yes or no?

 

[ferris]

Could you please be so kind to explained to us how well it works?
As I have put in the effort to explain to you why it won't!

I could of just written that it doesn't work but how in anyway is that informative or factual without proof to back up my opinions.

Kind regards,

Ferris

 

[Tin Man]

Check your metallurgy:

Spear shafts are typically made of 17-4 Precipitation Hardening stainless steel. It is a martensitic stainless (like 410 and 420), and is attracted quite nicely to a magnet. The martensitic part is important, because the crystalline structure of the steel has more to do with the magnetic attraction than does the iron content. 316 stainless steel is about 70% iron, and yet is not magnetic, while 17-4 is nearly the same (about 72%) but is quite magnetic. Likewise, price has little to do with iron content, as iron is just about the cheapest element in the mix. The other alloying elements (like nickel, chrome, molybdenum, etc.), the tightness of the specification, additional heat treatments, etc. have much more to do with the price of different stainless alloys.

The magnetic track works quite well. It takes only a small magnet, with less than 1 pound of pull, to keep the shaft secure in the track. A single 16mm band pulled to 300% elongation has a force of well over 100lbs. So the drag caused by the magnet is well less than 1% of the band pull force.

 

[Unclejake]

Could you please be so kind to explained to us how well it works?
As I have put in the effort to explain to you why it won't!

I could of just written that it doesn't work but how in anyway is that informative or factual without proof to back up my opinions.

Mate, it is just a button magnet, about 6 or 8mm in diameter, screwed into the end of the barrell. It helps hold the shaft down (open muzzle) while you are re-stringing the gun.

The magnet would not be strong enough to hold the weight of the shaft or even a quarter of the weight of the shaft if the gun was inverted

 

[JimCuda]

The magnet is not screwed into the wood. It is inlaid in the teak and covered, I checked on my Riffe 90. Sn Man has the metallurgy correct and not all SS are nonmagnetic. The effect on slowing the shaft is so miniscule compared to the drag of the water that it is inconsequential. The benefit of having a magnet for loading is nice. I wish they put one near the trigger mech so that it would make the shaft "pop" in place easier when reinserting it.

 

[ferris]

Thanks for your reply's.
Tin man, You are right about the different kinds of S/S but I did mention that in my post however I was wrong about the iron content and did try to explain the atomic structure. none the less thank you for your correction mate my apologies. Most quality S/S is actually supposed to be non ferrous ask any scrap metal place and they won't except ferrous S/S as scrap due to it's ability to rust quickly. All mine are non ferrous as they are high quality S/S.

Either way I didn't want to cause an argument just make the real point that this is just Hype to sell guns that's all and I believe that the consumer deserves the right to know this.

Unclejake, Thank you also for your reply,

Did you really have any trouble loading your speargun before this invention?
From my experience be it not anywhere near your's most likely, is that once the shaft is locked in the handle then you have absolutely no trouble in loading the gun even when putting loading the shaft on to the gun rail itself have you ever had enough trouble to warrant a magnet!

Like i said I wish not to argue and respect you both greatly as fellow spearo's.
I am sure you are both amazing free divers and would love to learn from your skills. Kind regards

Ferris

 

[ferris]

The magnet is not screwed into the wood. It is inlaid in the teak and covered, I checked on my Riffe 90. Sn Man has the metallurgy correct and not all SS are nonmagnetic. The effect on slowing the shaft is so miniscule compared to the drag of the water that it is inconsequential. The benefit of having a magnet for loading is nice. I wish they put one near the trigger mech so that it would make the shaft "pop" in place easier when reinserting it.

Your idea of putting a magnet closer to the handle is more in line with a good idea maybe putting one in the handle itself would make much more sense to me but I like the way you think mate!

 

[Unclejake]

The magnet is not screwed into the wood. It is inlaid in the teak and covered, I checked on my Riffe 90.

Mine is a Euro. I thought it was scewed in from behind (above) the shooting line anchor plate, but I could well be mistaken as I have never removed it.

 

[JimCuda]

Mine is a Euro. I thought it was scewed in from behind (above) the shooting line anchor plate, but I could well be mistaken as I have never removed it.

I thought the same thing until I got a piece of metal and ran it in the track. You'll immediately know where it is.
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[JimCuda]

Ferris, it helps when you don't have the shooting line over the shaft yet, as it holds the shaft in place. Additionally, many don't use a shooting line at all and freeshaft the fish (aim accurately).

The quantity of ferrous material isn't a testament to quality, the adjustments in metallurgy have many impacts. In this case, this SS is usually harder and stiffer than non-magnetic ones (barring really exotic materials). Also, 17-4 PH has a track record as a good spearfishing shaft material.
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[Tin Man]

I second Jim's thoughts. The "Quality" of stainless depends on what you want it to do. For example, 316 stainless stays bright and shiny in seawater forever, but it makes a poor knife blade because it is relatively soft. 420 stainless, on the other hand, can develop some discoloration in seawater, but makes a much better dive knife because it can be heat treated to be much harder than 316.

I don't know a lot about metallurgy, but it fascinates me. The difference between cast iron, vs. the cheapest carbon steel, vs. a high quality tool steel is little more than 1%-2% carbon content, and the tiniest traces of other elements.

 

[ferris]

Ferris, it helps when you don't have the shooting line over the shaft yet, as it holds the shaft in place. Additionally, many don't use a shooting line at all and freeshaft the fish (aim accurately).

The quantity of ferrous material isn't a testament to quality, the adjustments in metallurgy have many impacts. In this case, this SS is usually harder and stiffer than non-magnetic ones (barring really exotic materials). Also, 17-4 PH has a track record as a good spearfishing shaft material.
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I must admit I don't know anyone who doesn't use a shooting line as that is one quick way to lose your shaft if you don't stun the fish.
If your that accurate and never miss then I guess that may help.
As to the metallurgy yes but this also makes it more brittle and the amount of chromium changes everything. in this case we are referring to Martensitic S/S if it is ferrous.

Look I just think that Riffe guns are good as is they don't need any gimmick to sell them however the idea of having a magnet pop the shaft in the locking mechanism sounds very helpful to me. nice one!

 

[ferris]

17-4PH, uses about 17% chromium and 4% nickel

 

[ferris]

I prefer Austenitic S/S shafts or even better superaustenitic S/S if possible as it is much more superior in strength and corrosive abilities.

 

[ferris]

Austenitic S/S is whats commonly called the 300 serious ie; 304 or 316 superaustenitic S/S has high amounts of molybdenum and nitrogen that help it in anti corrosive ways.

 

[ferris]

But anyways all this makes me sound like a tosser so i'll quit while I'm ahead and say sorry if I have offended anyone I didn't mean to. Also I do not think I am more intelligent in anyway than anyone else on this forum truth be known you are all far more intelligent then I will ever be and that is fine with me as it will allow me to learn from the best!

Much love and good will to all on Deeper Blue.

Ferris

 

[Tin Man]

304 and 316 are more corrosion resistant, yes, but they are no where near as strong as 17-4. 316 has a yield strength of about 42 ksi, where 17-4 is anywhere from 130-190 ksi depending on the heat treatment.

 

[ferris]

304 and 316 are more corrosion resistant, yes, but they are no where near as strong as 17-4. 316 has a yield strength of about 42 ksi, where 17-4 is anywhere from 130-190 ksi depending on the heat treatment.

I completely agree with you mate I guess it depends on where you hunt most.
I am around reef a lot so 17-4 can be more brittle due to it's strength and if i hit reef which happens when you shoot something under a rock or in a cave you don't want brittle you want some more give. If you were chasing ocean fish then that would be of no consequence and so I guess the 17-4 would be the better option. thanks for your reply and knowledge it is appreciated.