X-terra S-shaft Modded For The Equinox

[steveg]

Tom,

I agree with you.  There are two things you need to be able to do, physically, to swing the Equinox.  One, as you said, you have to have the strength in your fingers/hand/arm to LIFT the machine, and KEEP it lifted, in the first place.  If you can't easily lift 3 pounds, and KEEP it lifted for several hours, then yes, detecting will not be comfortable.   And yes, if your main issue is that you struggle to lift the 3 pounds and carry it for several hours, then it will be even more difficult for you to lift and carry FOUR pounds.  So I agree with you there.

However, most folks I speak with have a consistent experience with the Equinox.  They say the machine feels "light" at first, but after several hours of swinging, they "feel it" in the wrist, forearm, etc.  Most of these users ALSO say that when swinging the 6" coil, the machine feels not only light AT FIRST, but that they can swing it all day, with no issues.  In other words, it REMAINS light.  But, they say, while even with the 11" coil the machine starts out feeling quite light, they become fatigued after a couple of hours, when swinging the 11", unlike when swinging the 6".

So, given that, let's consider this.  The 6" coil weighs about 10.6 oz.  The 11" weighs right around 19 oz.  So, by removing the 6" coil and adding the 11" coil, you are adding 8.4 oz. to the machine.  Adding 8 oz. is very unlikely, just from an "absolute weight" perspective, to be the "make or break" issue.  In other words, that 8 oz. of ABSOLUTE weight should not be enough to move the machine from the "I can swing it all day with no issues, it feels light as a feather" category, to the "after a couple of hours, I start feeling fatigued" category.  Said another way, it's not the "absolute weight" making most of that difference, it's the fact that you increased the nose-heaviness of the machine MUCH MORE SUBSTANTIALLY than just an 8 oz. addition of weight would otherwise suggest.  Why?  It's due to the physics/leverage arguments, of course.  Adding that 8 oz. at the "fulcrum" (i.e. the handle of the machine) would have MUCH less effect, than adding that same 8 oz. down at the end of a 3-foot long lever (the shaft).  Leverage, as we all know, multiplies the forces involved, substantially.  

So, to continue with the analogy, since adding 8 oz. of absolute weight to the machine when switching from the 6" to the 11" coil should not be a "deal breaker" in terms of comfort, adding 8 ounces of absolute weight to the machine (but as a counterweight, at the butt end of the machine) should ALSO not be a "deal-breaker."  Again, this is speaking from an "absolute weight" perspective.  However, when 8 oz. of weight is added in an EFFECTIVE location, relative to the coil, THEN that 8 oz. of counterweight can have a SUBSTANTIAL effect in balancing the machine, and thus making it counter-intuitively MORE comfortable to swing.  In fact, 8 oz. of counterweight is very close to being the amount needed -- when swinging the 11" coil -- to return the overall balance of the machine back to where it was when you were swinging the much lighter, 6" coil.  And therefore, for most people, adding 8 oz. of counterweight makes the machine SUBSTANTIALLY more comfortable to swing, with the 11" coil attached.  Again, it brings the "feel" of the machine back much closer to what it felt like, when swinging just the 6" coil.

I'd like to reiterate that I was not saying that simply switching to an S-shaft couldn't bring a bit more comfort, for some.  Switching to an S-shaft, you would definitely change, to some degree, which muscles are being used, and that might be at least a partial solution, for some.  My only argument is that the idea that adding counterweight "doesn't help" in making the machine "swing better" is not, in a large number of cases, a "true" statement.  Because, in fact, for many users, it in fact does...and there's science behind the reason that it does.

Steve

[nickelNdimed]

2 hours ago, steveg said:

You said counterweight did not help you, and that it just gave you a "heavier-feeling" machine.  My guess is that you were not using the right amount of weight.  If you put on some counterweight, and it's not enough to balance the shaft, then yes -- you have not solved the balance issue but instead you've just made the machine heavier, without the benefit of "balance."

With that said however, the pictures you showed do indicate that you "helped" the balance situation, in that the machine is "better balanced" in the picture where you have your weighting attached, versus the one without.  That would by definition mean you were exerting less "muscle effort" to keep the coil lifted off the ground with the counterweighted shaft, than you were with the un-weighted one.
 

Steve, the weight is an axle socket that weighs about a pound. I can probably get away with a little less at the end of shaft as the coil “floated” a little too much there as compared to the same socket attached further forward under the cuff. 

Either way, the weight needed at point A to offset the coil increase weight at B is roughly double. All of that extra weight is felt at C. Which is all then felt through the arm at each joint as more weight.  
 

Intuitively I feel the counterbalance may help someone suffering from wrist, forearm, and maybe elbow pain trying to use those muscles to force the coil to be level at an unbalanced state.  I feel this is were your  counterbalance concept would help most.  I wish it worked for me. 

I feel that pain or discomfort further up the arm or shoulder may be more related to the angle the detector is being held.  Shortening the shaft helped bring my arm closer.  I think the s-bend will allow My arm to be closer to vertical while the S-bend effectively moves the coil forward again(and so perhaps would offset coil ears like the F75).  I feel more weight hanging off an aching shoulder joint with a closer to vertical arm would certainly not help regardless of balance.
 

That’s my theory anyway so wanting to try other solutions.  It may also prove ineffective for my issue.  I certainly don’t want to be tethered to a harness with a less than 3lb detector and wireless headphones. 

[kac]

S shaft puts the center of gravity towards the upper part of your hand and not on the lower part of your wrist. Balance is the next issue where a nose heavy detector will put the forces towards your elbow. Last is the angle of the grip where your hand should be in a relaxed position and still have control.

Be nice if someone made a universal adjustable shaft system.

 

 

[Goldpick]

One of the main problems with the Equinox is the grip, more to the point your hand wanting to slip up the grip to the screen all the time.  Hence you tend to hold the grip quite tightly trying to prevent this from happening which can be tiring after a while.  In comparison the Simplex grip is more ergonomically correct with the notch below the screen preventing hand slippage resulting in a much more relaxed hand grip. 

I do see a lot of people with lower shafts near fully extended when it is maybe not so necessary (depending on how tall you are), personally I prefer a shortened shaft closer to my feet vs being extended out a fair way from my body.  If I can get a detector to effectively hang off my arm using the cuff strap and with the grip loosely held, then I know it can be swung comfortably - essentially an extension of my arm.  Same for the Deus S-stem, the balance and lack of weight is so good that I never need to run with a cuff strap - in fact it being a bit nose heavy tends to work in its favour.  The pivot point transfers the weight to the forearm via the cuff, and the grip only needs a moderately tight hand to keep it in check.  I guess that is why I still prefer s-bend shafts that have the main shaft in-line with your arm - most the detector weight/swing is controlled through the stronger muscles in your upper arm and shoulder vs relying on the hand/wrist. 

As for counter-balances, the jury is still out for me on adding extra weight for balance vs total swung weight.  Much like some saying that the CTX is perfectly balanced, though there is still a fair chunk of weight to swing/control for extended periods.

What Minelab should have offered is a universal control box with either an optional straight or S-stem shaft, similar to that provided with the Vanquish.  Though it is pretty hard to please all involved with so many personal preferences, having such options available should appeal to a wider user base.

[steveg]

Goldpick, 

Good points.  As for the CTX, I've never checked the actual balance on the CTX, but I do swing one, and I can tell you that having swung a "perfectly balanced" Equinox, the CTX is NOT "perfectly balanced."  It is DEFINITELY "more balanced" than an Explorer or E-Trac, but it absolutely does NOT feel "perfectly balanced."  Again, I've never checked to verify that, but if you go back to nickeldNdimed's pictures, and look his pictures, I am expecting that at best, the CTX would hang somewhere between his "no weight" picture (machine nearly vertical), and his "weight applied" (machine approaching "detecting position") picture.  In other words, I expect that the CTX is rather far removed from being "perfectly balanced" (perfect balance being defined as the machine "naturally" resting in "detecting position").

Steve

[Goldpick]

I should have said more well balanced vs perfectly balanced, with the battery pack offsetting some of the coil/shaft weight.  More to the point is even if it were "perfectly balanced", there is still a reasonable amount weight to have to control on each swing of the coil - something that I don't think I could comfortably deal with these days, especially after using much lighter platforms.  I do have to agree that the s-bend Explorer and Etrac shafts were definitely not well balanced.  Despite loving the SE Pro, I did end up with a bad case of "trigger finger" after several years of usage, mainly thanks to the crook angle of the hand grip.

I guess sometimes we are a bit spoiled with the current crop of detectors using minaturised electronics, lightweight lithium power sources and composite/carbon shafts, you do tend to forget what is was like hauling around the older FBS detectors in the past.

[steveg]

Goldpick -- no doubt!  I got such a bad case of "tennis elbow" swinging an Explorer, that I ended up having to become "ambidextrous" and learn to swing left-handed!  ?

Steve