GPX Carbon Rods?

[steveg]

schoolofhardNox --

I KNOW you were not trying to diss anyone, and you didn't!  ?

I was responding to your post as much from "surprise," as anything.  I had never heard of a carbon-fiber detector rod/shaft "snapping," or breaking, and while it does not surprise me that it COULD happen, under extreme circumstances, I was surprised that you knew of numerous instances...

In your first two pictures, with the crack running along the length of the shaft, that one makes ZERO sense to me.  Carbon-fiber tubes are made by wrapping sheets of woven carbon fiber, with glue/epoxy on them, around a metal rod that acts as a "form."  Multiple layers of this woven carbon fiber are wrapped, as I understand it, and then allowed to cure/harden.  Point being, the "weave" of the carbon fiber, in those multiple layers, should absolutely preclude such a straight-line "split" as is shown in that first picture -- to the degree that it makes me question whether that is actually a carbon-fiber tube at all...

The second two pictures show more of what I would expect a broken carbon-fiber tube to look like -- i.e. the rough/uneven edge of the break.  HOWEVER, in that second picture, that tube looks EXTREMELY thin...hard to tell in the picture, but it looks like it might even only be a millimeter or so...and so I'm not entirely surprised that one broke.  A normal "standard" wall thickness for a carbon-fiber tube is 2mm; the ones I use on my CTX 3030 lower rods, for instance, are actually 2.6 mm thick...which brings me to your next picture.  I've never seen a CTX rod break; even the factory Minelab rods are fairly stout/high-quality.  I understand that there could be significant forces applied to the rod, when hunting with a big coil in heavy surf (LOTS of drag/leverage applied to the rod, focused at that "connection point.")  Still, that's a surprising break to me; I wonder if sand was involved, such that over time, sand "wore down" the tube, right there at that connection point -- progressively introducing a small/focused "weak point" in the tube and thus facilitating that break.

IN ANY CASE, thanks for sharing the pictures.  I can see why you'd be a bit spooked by those experiences.  I can tell you that on my end, I have never had a customer with a tube breakage failure, and can't imagine that I will.  I'll never say "never," but I think it would be an unusual/rare circumstance.  

Like I said, I'm more than happy to send you some sample pieces -- I have lots, that I've cut off the end of my tubes when building rods, and you could have a look for yourself (IF, that is, you think you ever might want to purchase a rod/shaft from me for your CTX or EQX, and feel that it could be helpful toward easing any concerns you might have).

Otherwise, thanks for the interaction!  I appreciate it!

Steve

www.stevesdetectorrods.com

www.facebook.com/stevesdetectorrods

 

[schoolofhardNox]

Steve, Thanks for the information. I did have one idea on the Equinox shafts you are designing. I think I read that one version will have a screw on counter balance weight on the end of the machine. Did you ever consider the counterweight should not be screwed on, but have a cam lock to be able to slide it on the shaft to change the balance point to accommodate all weights of coils. It would be nice to be able to adjust that weight to suit your detecting situations if needed. Maybe that won't work, but I figured I'd throw it out there.

[Alluminati]

7 hours ago, schoolofhardNox said:

Steve, Thanks for the information. I did have one idea on the Equinox shafts you are designing. I think I read that one version will have a screw on counter balance weight on the end of the machine. Did you ever consider the counterweight should not be screwed on, but have a cam lock to be able to slide it on the shaft to change the balance point to accommodate all weights of coils. It would be nice to be able to adjust that weight to suit your detecting situations if needed. Maybe that won't work, but I figured I'd throw it out there.

I agree, a clamp on version might be easier.

I was thinking of making myself a hollow pod to clamp onto the end of the shaft that I could fill with sand or scrap lead that I find.

My season is pretty much over  until spring, so I can't really try much testing unless I go to a pool lol.

I'm open to collecting data on the amount of weight and how far away from your elbow it is.

Pardon me for stepping on toes, but SOHN hit on a thought I've been mulling over in the background.

[steveg]

Gents --

THANK YOU for the thoughts.  It is a very good idea in concept -- as having a telescopic counterweight system WOULD INDEED allow adjustment in the balance point simply by sliding the weight in and out (moving it nearer or farther from the "fulcrum").

However, I opted for screw-in, versus telescopic, for two reasons...

1.  If I went telescopic, one of my concerns was that the tube containing the weight would have to be smaller in diameter than the upper shaft to permit the telescopy -- i.e. I would need the tube to be of the diameter of the lower rod.  And that smaller-diameter tube would accommodate less lead, per inch, and thus would mean that longer lengths of counterweights would be needed to achieve the same "balance."  And I know many folks would like to keep those extensions as short as possible.

2.  More significantly, though, is this -- the amount of distance available to "telescope" the counterweights into the butt-end of the upper shaft is EXTREMELY LIMITED, due to the through-bolt that holds the arm cuff.  This is especially problematic for someone who uses the "most rearward" arm cuff hole -- in which case you'd only have about  1 3/8" of telescopic capability, as limited by that through bolt.

So, while in the absence of the arm-cuff through bolt, the "cam lock/telescopic counterweight" idea is superior in theory, these were the limitations that led me to opt for the "screw-in" idea.

The ONLY way I know of, to use the telescopic idea, would be to make the shaft longer at the butt end -- i.e. -- lengthen the part that extends beyond the arm cuff holes, and then put the cam lock out there at the butt end of the now-longer shaft.  Then, the counterweight would have more "shaft" to telescope into.  The problem there is, shipping boxes I have been able to procure are limited to 37" in length...so I really can only add about an inch additional to the butt end...which would only increase telescopic capability (if using the rear-most cuff hole to about 2 3/8")...

Thoughts?

Steve

[steveg]

Gentlemen...

I am still pondering this idea (of "telescopic" counterweights) a bit more; as I said, I ruled it out initially, due to the lack of telescopic distance available, AND to the fact that the counterweights would have to be longer, due to the smaller-diameter tubes.  

I calculated how much longer of a tube would be needed to achieve the same amount of weight; I can get roughly 8 oz. of lead pellets in a roughly 5" tube that is the diameter of the upper shaft.  I calculated that it would take about a 6 1/4" long tube, the diameter of the lower shaft, to get that same 8 oz. of lead pellets inside.  Hmm.  Not TOO terribly much longer.

I know this is taking this thread WAY off topic, but -- let's say there was only that 1 1/2" or so of telescopic ability -- i.e. not that much.  Would it still be a better idea, in your minds, to attach/detach a slightly longer tube, via a clamping cam lock, versus unscrewing tubes via threaded connectors?

Just curious...

Steve

[schoolofhardNox]

1 minute ago, steveg said:

Gentlemen...

I am still pondering this idea (of "telescopic" counterweights) a bit more; as I said, I ruled it out initially, due to the lack of telescopic distance available, AND to the fact that the counterweights would have to be longer, due to the smaller-diameter tubes.  

I calculated how much longer of a tube would be needed to achieve the same amount of weight; I can get roughly 8 oz. of lead pellets in a roughly 5" tube that is the diameter of the upper shaft.  I calculated that it would take about a 6 1/4" long tube, the diameter of the lower shaft, to get that same 8 oz. of lead pellets inside.  Hmm.  Not TOO terribly much longer.

I know this is taking this thread WAY off topic, but -- let's say there was only that 1 1/2" or so of telescopic ability -- i.e. not that much.  Would it still be a better idea, in your minds, to attach/detach a slightly longer tube, via a clamping cam lock, versus unscrewing tubes via threaded connectors?

Just curious...

Steve

I see what you are getting at with your design. Skimming through a lot of post doesn't let me digest them all very well  I originally envisioned your counter balance to look like a small tube with a small ball on the end of it. Now I realize that is a tube filled with weight (no ball on the end). So I can see why the extension length may be an issue. For some reason I just thought of how some digging trowels  have that 1-2" ball on the end.

[Alluminati]

I figure as long as I can make mine smaller then a Excalibur pod I'm golden.

[steveg]

SOHN -- got it!  Thank you for your reply!  Yes, it would be lead-filled tubes, no "ball" of any sort on the end.

I will not derail your post any further!  ?

Thanks!

Steve

[Goldseeker5000]

Hey Steve do you have any ajustable rods for the Gold Monster?