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#1

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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03 October 2020 06:25 pm

Ok, so I've done a search on the forum and the net looking for info regarding shaft materials for a metal detector.

Some background- After spitting venom for some time about the quality of Minelabs components (I've long said that I want their control box and would rather make up the rest of my detector from aftermarket parts and accessories), I've decided/realized that perhaps I've been a little too harsh on Minelab....

Reason being, I run big coils. I started off for a while using an 18" Commander DD, then I bought myself a 21" x 17" Detech SEF (which I still own), added to the collection with a 20" NF Mono Advantage, but for quite some time now I've been running a NF 25" DDX, and I understand that in all fairness to Minelab, the stock standard shafts and associated parts and materials were never designed to run such big heavy coils constantly.

First I broke a shaft lock and had to replace it with one I bought from Nenad. Then I broke that one so bought myself a whole new Minelab upper shaft and a Coiltek Carbon Fiber lower shaft. Not long after, the lower shaft split completely in a straight line from one end to the other which caused the DDX to flop around on the end and drive me nuts.

So........ I bought another Minelab lower shaft to replace it, only to then have the shaft lock on the upper go again devil

So, then I locked the shaft lock as best I could, and filled the bloody thing up with Supa-Glue, AND drilled an 8mm hole right through the guts of the shaft just above it, where the lower shaft passes inside the upper shaft, tapped an 8mm thread in the hole and inserted an M8 stainless steel screw through the whole bloody lot with a stainless steel Nyloc nut locking the whole thing together!!!! Sure, no longer height adjustable, but it's set to my height and is perfect for 'lil ol' 5' 6" me.

Thinking that I had outsmarted Minelab, Coiltek, Nugget Finder, and all of the Detecting gods in total, I then enjoyed some months of trouble-free detecting with my whopping great coil, and I must say I finally got to experience the pleasures of a stiff shaft, including I might add, finding my first 1.5g nugget perfect

Then...............Last week what happens? The eye insert of the bottom shaft (the stem that is glued into the bottom end of the lower shaft and has an eye that pushes in between the coil lugs for the coil to pivot on) decides to fall out of the end of the lower shaft

1601709251_1581901842_suicideemoji.jpg

I've supa glued the offending part back into the lower shaft today, which will get me by, but I'm sick to death of this stupid game, and I don't like the idea of continually adding more and more metal in the way of screws and nuts into the shaft equation so close to a large sensitive DDX coil. Has anybody else who runs a GPX with big heavy coils had any experience with Sandy Shafts and their compression fitting style shaft lock in a combined upper and lower set-up? Are they any better than Genuine Minelab shafts?

Thanks in Advance,
Deepseeker

Last edited by Deepseeker (03 October 2020 06:32 pm)


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#2

goldierocks
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Joined: 10 January 2015
Posts: 3,260
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03 October 2020 07:01 pm

Politeness prevents me from quoting one of your sentences - only to say "how true".


Robert Benchley...
I have kleptomania, but when it gets bad, I take something for it.

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#3

mbasko
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From: Central West NSW
Joined: 27 January 2015
Posts: 4,815
Member
03 October 2020 07:52 pm

I converted over to a Sandy Shaft set up a few months ago.
The lock nut on the Minelab upper still does up, to a point then loosens like it's stripped, but anything bigger than a 14" coil felt like it was flopping around all the time.
Always wanted to try out the Sandy Shaft so took the plunge.
The lock nut set up on the Sandy Shaft definitely feels a lot sturdier than the Minelab shaft lock nut & tightens with less force. It doesn't feel like it will fail/strip like the Minelab one.
It's early days for me yet really but I'm also finally experiencing the "pleasures of a stiff shaft" yikes argh
My Coiltek lower shafts also fit into the Sandy upper nicely too - a little bit tight if anything but I'm using a couple of them without issue.

Last edited by mbasko (03 October 2020 07:53 pm)


Everything we use comes from mining or farming.

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#4

OzzieAu
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From: Adelaide
Joined: 04 November 2014
Posts: 1,273
Member
03 October 2020 08:46 pm

Yep, nice upper shaft, apart from the fact that some lowers are a little tight, so a little vaseline on the O ring helps insertion playful
And yes, it certainly is stiFFer. power
Nenad has them.

Last edited by OzzieAu (03 October 2020 08:48 pm)


GPX5000..2Evo’s...Whites SPP...Makro Multi Kruzer... ProFind pointer.

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#5

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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03 October 2020 09:02 pm

Thanks guys. I read your replies so took the plunge. Nenad only had the Lower Shaft listed, so I did a google search and found both the Upper and Lower available from Townsville Prospecting World, and ordered both express post. Hopefully that will be the end of the saga!

Thanks again guys,

-D.S


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#6

Anniegee
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From: WERRIBEE, VIC
Joined: 26 November 2019
Posts: 398
Member
04 October 2020 12:20 am

Very amusing accounts by you fellas discussing your shaft/coil/nut problems. Ask most of us women and we'll tell you "size doesn't matter"...but using super glue on a broken shaft...well that's another thing altogether...sorry, couldn't help chipping in lol lol lol


I am willing to be pleasantly surprised!

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#7

Goldfreak
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Joined: 13 May 2017
Posts: 2,475
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04 October 2020 05:44 am

Anniegee wrote:

Very amusing accounts by you fellas discussing your shaft/coil/nut problems. Ask most of us women and we'll tell you "size doesn't matter"...but using super glue on a broken shaft...well that's another thing altogether...sorry, couldn't help chipping in lol lol lol

Was about to say a whole bunch of stuff but better just shut up instead lol

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#8

just starting
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Joined: 28 December 2018
Posts: 1,327
Member
04 October 2020 06:52 am

There is a heap of funny stuff i could write , but that won`t help your problem .

Have you looked into reinforcing the carbon fiber shafts with a hard tubing over the outside to stop or reduce any flex ? Sounds like you punish your machine a fair bit . You need to reduce the stress points from using the coil and maybe run a strong rope or string or thick fishing wire or thick bungee cord from the bottom of the shaft to the top near the head unit to help with the weight distribution.
Also , if gluing, i would use a good quality 2 part epoxy glue, not superglue . Smells lethal before it dries .but is good stuff. Some have made that lower coil pivot lug out of wood. Probably some sort of ply board. You need to re-distribute the weight in the coil and lower shaft to other areas of the detector to minimise stress on them.

Have you got pics of your broken shaft so we can see the problem ?

Last edited by just starting (04 October 2020 06:53 am)

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#9

Adrian ss
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Joined: 08 December 2018
Posts: 236
Member
04 October 2020 08:13 am

Have never had any stiff shaft problems. You bloke must really flog yours to death. Some of yez have even broken yer shaft. I can see how that could be a problem butt, errr I mean but. especially when pounding rough territory. argh argh argh big_smile big_smile big_smile

Last edited by Adrian ss (04 October 2020 08:16 am)

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#10

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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04 October 2020 08:24 am

Thanks just starting. I've hopefully solved the problem once I have received my Sandy upper and lower shafts. I already run a bungy that is anchored just above where the upper and lower shafts join, that is hooked onto a hip stick that is attached to my harness. I use a guide arm also, which helps control the coil and stops things from flapping around and twisting to some degree, but I have been thinking for a while now that maybe two bungy's may help, or better still some type of guide arm that attaches closer to the coil on the lower shaft.

Thinking about your fishing line/rope idea though has made me think that perhaps another idea may also be to get some thick fiberglass or carbon fiber tubing and securing it to the upper and lower shafts at the bottom, midway, and at the front of the control box in some way that it kind of resembles an over and under shotgun.

The superglue is just until I receive my Sandy upper and lower shafts. There's not much left of the unit now that is genuine Minelab, other than the control box itself and also the quicktrack handle (and even that has been replaced once- if it goes again I'll replace it with a hardwood version). It's a bit like the old story of the janitor who has had the "same" old broom that he has had for nearly 30 years. He's only had to replace the head three times and the handle twice. smile

I don't think I'm overly harsh on my gear, everything gets treated well and nothing gets abused, other than I think the problem is that none of Minelabs equipment was made to have a dirty great big 25" half bundle wound/ half spiral wound coil with a solid skid plate, hanging off the end permanently.


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#11

Manpa
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From: Sheidow Park, SA
Joined: 06 January 2018
Posts: 3,747
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04 October 2020 08:29 am

“Sandy Shafts” sounds like a name for an “adult” entertainer/movie star . playful


One of these days Ma!

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#12

Dave law
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From: East Maitland
Joined: 09 February 2015
Posts: 1,350
Member
04 October 2020 08:48 am

1601761638_9315a65b-bbbd-440d-b159-411e72839a00.jpg carbon fibre may be the answer.


I enjoy haveing my electromagnetic feild disturbed. XP Deus. 9" low&9"hf coil MI6 pinpointer. Diamond Digger. Oldest coin. 1797 Cart wheel penny X2. FOM winner 5/17.

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#13

just starting
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Joined: 28 December 2018
Posts: 1,327
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04 October 2020 10:47 am

Manpa wrote:

“Sandy Shafts” sounds like a name for an “adult” entertainer/movie star . playful

Dare you to google it !!!!!

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#14

silver
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Joined: 19 December 2013
Posts: 17,075
Member
04 October 2020 11:32 am

Sounds like a bloke with a problem needs to make a wooden shaft for complete and utter pleasure in performance.... could end up in a split with a splinter at worst....wood deepend on how hard the going is.... but I'm betting you could get over mountain with a wooden shaft in the long run... might bend a little bit as your poking around in the bush with it.... but nothing like a plastic one(those things bounce around like rubber as soon as you put em to work)
Anyway... good luck with it tongue


What a great day ! ,... " I'll see you in the field ".

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#15

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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04 October 2020 12:35 pm

Dave law wrote:

I've already searched some of that stuff thanks Dave Law, problem is though it never seems to come longer than 1mtr, so once again we are back to joining two pieces. It's a shame nobody has come up with custom pieces made to length. Having said that I can already see the problem there- Starting with price, and ending in the fact the most postal services won't ship anything over 1.05 mtrs long, meaning specialty courier/freight services and yet again more cost.

I guess if I could find out the correct/best/strongest way to slide one piece of carbon fiber tube inside another and bond them together, I maybe could make my own shaft to length. I thought my Coiltek lower was made from Carbon fiber by the way, but that split as though it was a straight seamed tube. I thought good carbon fiber tubing was supposed to be seamless and not capable of doing that???

Update: I just had a look at the playwithcarbon site that Davelaw has mentioned. They also sell it in 2mtr lenghths cool

Last edited by Deepseeker (04 October 2020 12:42 pm)


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#16

EVIE/BEE
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From: 6383, WA
Joined: 16 November 2018
Posts: 630
Member
04 October 2020 01:41 pm

You spend thousands on a detector, i don't understand, things wear and break.

Just buy a couple of spares.
I have one on each coil, saves a lot of messing around. roll

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#17

just starting
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Joined: 28 December 2018
Posts: 1,327
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04 October 2020 02:13 pm

Have you asked a minelab dealer if they have a solution ? It may have been something they have come across before.

#18

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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04 October 2020 02:18 pm

It's not so much about wear and breaking Evie/Bee, it's the moving around of a big DD on the end of a flimsy stick. As I said earlier, that's not Minelabs fault, the structure was never designed to take such a big solid DD. If I could end up with a unit that doesn't break or fall to pieces on every second or third day trip I'd be happy big_smile

Last edited by Deepseeker (04 October 2020 02:27 pm)


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#19

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
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04 October 2020 02:26 pm

just starting wrote:

Have you asked a minelab dealer if they have a solution ? It may have been something they have come across before.

I guess it's a bit like dropping a big V8 into a small 4 cylinder car and then complaining to the manufacturer about the useless front suspension and the tail shaft snapping. No, it's all good, I'm sure the Sandy shaft will be fit for purpose from what I've heard and read since yesterday.


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#20

Manpa
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From: Sheidow Park, SA
Joined: 06 January 2018
Posts: 3,747
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04 October 2020 02:27 pm

just starting wrote:
Manpa wrote:

“Sandy Shafts” sounds like a name for an “adult” entertainer/movie star . playful

Dare you to google it !!!!!

Yeah, nah, yeah, nah, yeah! playful


One of these days Ma!

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#21

EVIE/BEE
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From: 6383, WA
Joined: 16 November 2018
Posts: 630
Member
04 October 2020 03:25 pm

Now i understand.. try schedule 80 pvc.
Super strong will do the job.

https://www.pvcfittingsonline.com/resou … le-80-pvc/

#22

IBGold
Newbie
Joined: 19 February 2020
Posts: 9
Newbie
04 October 2020 04:01 pm

Excel Composites in Melbourne sell carbon fibre fibreglass composite shaft in 2. meter length's in the correct sizes you require it is what I use for my own shafts.

Regards, Ian. big_smile

1 user likes this post: Deepseeker

#23

pinfire opals
Banned
Joined: 16 February 2019
Posts: 415
Banned
04 October 2020 06:47 pm

What were the shafts the 2 Vic boys were using this year on AGH, looks like they can handle a large coil.

#24

Deepseeker
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Joined: 13 August 2018
Posts: 1,701
Member
18 October 2020 02:10 pm

I gave the Sandy Shaft upper and lower combination a trial run near Kingower yesterday- thumbsup thumbsup thumbsup thumbsup

No twisting, flopping, flexing or fighting with the Minelab toy-like shaft twist lock. Sandy Shafts are one purpose built piece of equipment, and the shaft locking system is precision machined and chalk and cheese compared to Minelab's effort. Not cheap, but then not much worthwhile and quality is......

One other thing of note is that I no longer have an 8mm stainless steel bolt through the upper shaft to hold the two shafts together. Neither do I have an aluminium upper shaft anymore, plus I have also replaced the stainless steel screw and nut on the bungy clamp with a coil lug plastic srew and nut. Now I'm not sure how much of the sensitivity improvement is the absence of stainless steel bolts/screws/nuts, aluminium upper shaft, or the carbon composite sandy shafts and the fact that I can dangle my 25" DDX coil a couple of inches further away from me and the control box, on a longer shaft combo with still zero twisting and movement, or indeed a combination of all these things?

But, I will say this unequivocally- I have an enormous increase of sensitivity as a final result of this act of jettisoning Minelabs feeble offerings.
A few times when retrieving a small target (and remember, I had already pinged a 1.5 grammer with the 25" DD-x before the minelab shaft dummy spit), I kept getting a signal on the weekend as I moved my arm with the scoop from the hole to my coil to check/discard the soil. It drove me nuts! I checked to see if something metal was stuck in the scoop- Nope. Checked around my shirt sleeves/cuffs to see if something was caught up- Nope. Tried it without my gloves on- Nope- AAAAARGGHH!.

Then I realized- it was as I turned my head left to right, right to left- from the hole to the coil, and then from the coil to the hole. The Only things that I have out front are the fillings in my teeth and the glasses on my face. Of course, it was the glasses (damned lucky actually, as I didn't fancy getting all of my teeth pulled for the sake of a cleaner signal!).

That has never happened before. I have to check the scoop at complete arms length with my head back as far as I can. That's incontrovertible proof for me. The new shaft set-up is an all out winner thumbsup

Thanks again everyone who contributed above,
With special thanks to Mbasko and OzzieAU for sharing their experiences with the product thumbsup clap

Last edited by Deepseeker (18 October 2020 02:32 pm)


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#25

ProspectorPete
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From: Narre Warren Sth , VIC
Joined: 11 September 2014
Posts: 1,299
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18 October 2020 04:38 pm

Hey Deepseeker, that's great you've solved the problem of the sloppy shaft.
Now you have the new issue of having to lean right back at arms length with the scoop while finding the target, I had a similar issue when I used to detect with dual speakers and they would cause bad feedback when the target in the scoop passed over the coil, I came up with this easy fix, it's just a 400mm length of 32mm PVC over the scoop handle and fixed with liquid nails.
Works a treat and thought it may help solve your new issue.

1602999495_20201018_161936.jpg


GPX4500/NF Coils/sP01/STUMPY Picks
GM1000 Equinox 600

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