Detector Coil Weights.

HH.

John



Edited 6 time(s). Last edit at 10/07/2016 11:45AM by auminesweeper.

I think there is some merit to just quoting the coil weight, as well as coil+cable/connector.
The coil always sits on the end of your shaft - that makes it the main contributor to the weight imbalance. The cable gets progressively nearer to the detectors balance point, so it's weight becomes less obtrusive.
Also, some coils come with quite long (and hence heavier) cables, especially for machines that can be hip-mounted. A good example is the XP GMP / GMAXX, which have a lot of cable tightly coiled up, nearer the control-box end.

Weighing coils like you have is the only sensible scientific way of comparing them. I often read people reviewing a larger coil, and non-scientifically state nonsence like " it doesn't feel any heavier than the stock coil". Give us the proof. It usually shows that the coil is significantly heavier, as you might expect.

Technical point: Most of a coils weight is the plastic case, the resins, foams inside it. And it's not that affected by the copper wire itself. In fact, the amount of copper doesn't go up in proportion to the coil size, as you might think. Bigger coils have less turns of wire, though the wire gauge ( US: gage) does vary too.

Pimento Wrote:
-------------------------------------------------------
> I think there is some merit to just quoting the
> coil weight, as well as coil+cable/connector.
> The coil always sits on the end of your shaft -
> that makes it the main contributor to the weight
> imbalance. The cable gets progressively nearer to
> the detectors balance point, so it's weight
> becomes less obtrusive.
> Also, some coils come with quite long (and hence
> heavier) cables, especially for machines that can
> be hip-mounted. A good example is the XP GMP /
> GMAXX, which have a lot of cable tightly coiled
> up, nearer the control-box end.
>
> Weighing coils like you have is the only sensible
> scientific way of comparing them. I often read
> people reviewing a larger coil, and
> non-scientifically state nonsence like " it
> doesn't feel any heavier than the stock coil".
> Give us the proof. It usually shows that the coil
> is significantly heavier, as you might expect.
>
> Technical point: Most of a coils weight is the
> plastic case, the resins, foams inside it. And
> it's not that affected by the copper wire itself.
> In fact, the amount of copper doesn't go up in
> proportion to the coil size, as you might think.
> Bigger coils have less turns of wire, though the
> wire gauge ( US: gage) does vary too.

Well that's right,

John.



Edited 3 time(s). Last edit at 10/07/2016 11:47AM by auminesweeper.

It's a complicated business, this weight thing. It's not just the total detector weight, it's the balance of the thing, and also the 'moment of inertia'.
So:
*Machines like the Minelab CTX are very heavy, but because they're well balanced, they don't feel quite at bad in the hand as users expect.
*The XP Deus is horribly balanced, but because it's also light, they seem to get the thumbs-up from users.
*If you balance a machine well, you still have to forcibly change it's direction at the end of every sweep, and this gets very tiring. I suspect this will be noticeable to CTX users. This is the effect of moment of inertia.

The key thing that features in all these measures is the coil weight. If you could make that lighter, then everything else would be much simpler. I've heard of aluminium (US: aluminum) wire being used in coils, but it's not ideal, making good electrical connections to it is troublesome, for one thing. And it has thermal issues, too.

There are a few other things you can do. Have the shaft shorter, so the coil is nearer your feet. Use a lighter lower rod. You'd probably have to homebrew this. High-performance rods are used in fishing gear, stunt kites, archery arrows amongst others. Move the battery pack to an under-the-armcup location. Don't use coil protectors if you can avoid them.

If your 6x10 Eclipse is 32 oz, then either it's full of water, or you have another 6x10 coil stuck to the bottom of this one.

Geotech Wrote:
-------------------------------------------------------
> If your 6x10 Eclipse is 32 oz, then either it's
> full of water, or you have another 6x10 coil stuck
> to the bottom of this one.

Lol, Yes Carl I was thinking that,

John.



Edited 1 time(s). Last edit at 10/07/2016 11:48AM by auminesweeper.

I suggest you check your scales, many of your numbers are way off. 6x10 coils are about a pound. Not 2 pounds.

Wow my entire deus with remote, shaft, 9" coil, and coil cover weighs a smidge less than the 6x10 eclipse. Lol

Geotech Wrote:
-------------------------------------------------------
> I suggest you check your scales, many of your
> numbers are way off. 6x10 coils are about a pound.
> Not 2 pounds.

Well Carl I checked them and Recalibrated them just to make sure

John.



Edited 3 time(s). Last edit at 10/07/2016 11:49AM by auminesweeper.

[www.nwdetectors.com]

detectingMO Wrote:
-------------------------------------------------------
> Wow my entire deus with remote, shaft, 9" coil,
> and coil cover weighs a smidge less than the 6x10
> eclipse. Lol

That maybe true but the point Pimento made about the balance is spot on as the overall weight is minor unless you are severely disabled . The only really important figure is the amount of force required to change directions when swinging. I believe it was Tom who referenced how the F75 was designed with that in mind so that the balance required the smallest force possible to change directions. Swing a F75 then swing the 11" Deus and the difference is remarkable. Coil weight should come with both a weight figure as well as figure in newtons per swing.

shoveler Wrote:
-------------------------------------------------------
> detectingMO Wrote:
> --------------------------------------------------
> -----
> > Wow my entire deus with remote, shaft, 9" coil,
> > and coil cover weighs a smidge less than the
> 6x10
> > eclipse. Lol
>
> That maybe true but the point Pimento made about
> the balance is spot on as the overall weight is
> minor unless you are severely disabled . The only
> really important figure is the amount of force
> required to change directions when swinging. I
> believe it was Tom who referenced how the F75 was
> designed with that in mind so that the balance
> required the smallest force possible to change
> directions. Swing a F75 then swing the 11" Deus
> and the difference is remarkable. Coil weight
> should come with both a weight figure as well as
> figure in newtons per swing.

Water hunting trains you how swing and overcome the inertia. Let the coil slow by itself at the end of that swing and gradually increase the force as the coil changes direction.

____________________________________________________________________________________________________________
In a democracy, it is difficult to win fellow citizens over to your own side, or to build public support to remedy injustices that remain all too real when you fundamentally misunderstand how they see the world.

And regarding the scale calibration - surely you can get hold of a pile of good coins, their weight is well established and quite accurate.

shoveler Wrote:
-------------------------------------------------------
> detectingMO Wrote:
> --------------------------------------------------
> -----
> > Wow my entire deus with remote, shaft, 9" coil,
> > and coil cover weighs a smidge less than the
> 6x10
> > eclipse. Lol
>
> That maybe true but the point Pimento made about
> the balance is spot on as the overall weight is
> minor unless you are severely disabled . The only
> really important figure is the amount of force
> required to change directions when swinging. I
> believe it was Tom who referenced how the F75 was
> designed with that in mind so that the balance
> required the smallest force possible to change
> directions. Swing a F75 then swing the 11" Deus
> and the difference is remarkable. Coil weight
> should come with both a weight figure as well as
> figure in newtons per swing.

I've swang them all just about. Agree it is balanced better. Hard not to be nose heavy when most of the deus weight is the coil. At the end of the day though, regardless of swing, you will have been carrying a detector 75% heavier.

Weight is a non-issue for me but it sure is nice having ultra light, compact, and wireless. A bit liberating actually.

Whites coils are definitely boat anchors

Weight is one aspect....ergonomics another....Some control box areas are heavy and heavy coil balances them out.

detectingMO Wrote:
-------------------------------------------------------
> shoveler Wrote:
> --------------------------------------------------
> -----
> > detectingMO Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > Wow my entire deus with remote, shaft, 9"
> coil,
> > > and coil cover weighs a smidge less than the
> > 6x10
> > > eclipse. Lol
> >
> > That maybe true but the point Pimento made
> about
> > the balance is spot on as the overall weight is
> > minor unless you are severely disabled . The
> only
> > really important figure is the amount of force
> > required to change directions when swinging. I
> > believe it was Tom who referenced how the F75
> was
> > designed with that in mind so that the balance
> > required the smallest force possible to change
> > directions. Swing a F75 then swing the 11" Deus
> > and the difference is remarkable. Coil weight
> > should come with both a weight figure as well
> as
> > figure in newtons per swing.
>
> I've swang them all just about. Agree it is
> balanced better. Hard not to be nose heavy when
> most of the deus weight is the coil. At the end
> of the day though, regardless of swing, you will
> have been carrying a detector 75% heavier.
>
> Weight is a non-issue for me but it sure is nice
> having ultra light, compact, and wireless. A bit
> liberating actually.
>
> Whites coils are definitely boat anchors


You can balance an anvil but its still heavy.

Thank you John!

This is a good informative post, an eye opener for sure and will help us select coils for weight purposes and maybe depth as you found the 10" DD was deeper than the 950 coil.

Thank you John!
Paul

Apolonio (CA) Wrote:
-------------------------------------------------------
> Thank you John!
>
> This is a good informative post, an eye opener
> for sure and will help us select coils for weight
> purposes and maybe depth as you found the 10" DD
> was deeper than the 950 coil.
>
> Thank you John!
> Paul

The Whites 10" DD is the Best standard Coil I have ever seen, It can see your bare hand between 4 to 6 inches and it can see bits weighing 0.02 to 0,03 grams, When you turn up the machine the Coil just comes to life and when you consider that it can out run a Concentric of equal size that is quite an achievement,

PS I have ordered another couple of sets of Scales so I will Double check my figures, Ok.

John.

My swing arm just burns up if I'm constantly battling the inertia of a light machine needing a brisk sweep for a decent report.
You just can't try this in the shop, it feels light as a feather. Out detecting it's a pain to use.

Beach hunting with the Excalibur for 4 hours, I can time my swing to my step. It's a heavy thing but we just click and my swing arm doesn't feel any worse for wear.

The CTX is so and so in the hurt department. Fairly heavy, but you can creep it along and still get a decent report.

In the end, you just need a machine which clicks with you in so many ways.

Pimento Wrote:
-------------------------------------------------------
> It's a complicated business, this weight thing.
> It's not just the total detector weight, it's the
> balance of the thing, and also the 'moment of
> inertia'.
> So:
> *Machines like the Minelab CTX are very heavy, but
> because they're well balanced, they don't feel
> quite at bad in the hand as users expect.
> *The XP Deus is horribly balanced, but because
> it's also light, they seem to get the thumbs-up
> from users.
> *If you balance a machine well, you still have to
> forcibly change it's direction at the end of every
> sweep, and this gets very tiring. I suspect this
> will be noticeable to CTX users. This is the
> effect of moment of inertia.
>
> The key thing that features in all these measures
> is the coil weight. If you could make that
> lighter, then everything else would be much
> simpler. I've heard of aluminium (US: aluminum)
> wire being used in coils, but it's not ideal,
> making good electrical connections to it is
> troublesome, for one thing. And it has thermal
> issues, too.
>
> There are a few other things you can do. Have the
> shaft shorter, so the coil is nearer your feet.
> Use a lighter lower rod. You'd probably have to
> homebrew this. High-performance rods are used in
> fishing gear, stunt kites, archery arrows amongst
> others. Move the battery pack to an
> under-the-armcup location. Don't use coil
> protectors if you can avoid them.

HH
Johnb

Edit



Edited 1 time(s). Last edit at 10/07/2016 11:52AM by auminesweeper.

I Have just bought 3 sets of Scales ,

john



Edited 2 time(s). Last edit at 10/07/2016 11:53AM by auminesweeper.