Broken Minelab CTX 3030 Coil Ear

[phrunt]

I used PVC pipe glue and primer, seemed to work well.

[phrunt]

This guy normally repairs model trains it seems but he's done a great video on CTX coil ear repair, which obviously could be applied to the dodgy Equinox coil ears also.

He runs through the entire process in an easy to understand way and his repair looks fantastic when finished and much stronger than the original.

I didn't do mine near as fancy as this guy, my 17" coil had a small crack in the ear going from the bolt hole outwards my guess from me over tightening the bolt to try keep the big coil stable without flapping in the wind, by putting on the ABS 3D printed bracket using a plastic glue that chemically dissolves the two plastics to melt together seeing the coil is also made of ABS it worked pretty well, nice and solid.  I used PVC glue and primer on my 17" coil and ABS glue on my 11" coil and both seemed to work as well as each other, both melted the plastics during the bonding.

Because of the way it was glued there is no way for water or dirt to get up under the coil ear stiffener to cause me any grief, it's completely bonded.

I decided yesterday to do the same with my 11" CTX coil, it had nothing wrong but it's only a matter of time.  One thing I have noticed with the CTX is the washers just don't seem thick enough so the ears bend inwards as you tighten the bolt, and you have to tighten the bolt fairly tight to hold the coil in place or it flops around.  It seems quite a bad design.  In case it was just my washers were wearing thin I bought a new pack of washers which made no difference at all. 

I put the ABS glue the 11" coil on and mounted the stiffener using clamps overnight last night

You'll notice on my coil cable where it runs up into the shaft I've shrunk down some dual wall heat shrink to protect the cable there, the CTX has such a bad design where the cable goes up into the shaft, even though my coil was near new I already had signs of wear on the cable where it runs up into the shaft.    Much like the coil ears the cable going into the shaft like that almost seems like it was designed to fail.

So now my 11" has stronger ears too, I've got far more confidence in the ears not breaking now.  It's a real puzzle to me why the CTX is such an old detector now and so many people with it had coil ears fail yet when Minelab released the Equinox and Vanquish they made no effort at all to improve the badly designed ears.  Now they're swapping out so many coils for people under warranty for broken ears that could have easily been prevented with a better design.  The ones that break outside of warranty I encourage people to fix and not buy a new coil, why pay Minelab the money for their screw up, fix the thing, it can be done and it's not all that hard to do and you'll end up with a better coil after it's done than the new replacement would be.

I'm not sure if I'll bother doing my 6" coil until it breaks, for a start I'll probably rarely use it as I bought the CTX for coins, I have little need for a small coil on a coin detector in my hunting environment.  The 6" is so light it doesn't put much stress on the ears either, and you don't need to tighten the bolt as tight to drop the 6" moving around as it's so small and light.  The 17" needed tightened up pretty tight being such a big heavy coil.

In a note to Minelab, or perhaps a plea, Minelab, if you're working on an Equinox 1000 PLEASE make new coil ears for it's coils, don't give us this weak rubbish on anymore detectors.  You're starting to have competition now, you can't be so relaxed with your lax build quality anymore, it's become the butt of jokes for the competition. 

[GB_Amateur]

14 hours ago, phrunt said:

...Using a plastic glue that chemically dissolves the two plastics to melt together seeing the coil is also made of ABS it worked pretty well, nice and solid.  I used PVC glue and primer on my 17" coil and ABS glue on my 11" coil and both seemed to work as well as each other, both melted the plastics during the bonding.  (emphasis mine)

IMO, this is the key part of this kind of repair.  Unfortunately the product used in the 2nd video (Bison Plastic Adhesive) is not (easily) available here in the USA.  Anyone know of an equivalent product here?

I've learned from experience that binding platics is particularly tricky and just using the obvious, like Super Glue (cyanoacrylate), generic 5 minute epoxy, or whatever is in the cabinet is typically not going to work.  (Yes, they look good until stressed in the field and then you're back to square 1.)  Injection molded plastics (such as ABS here) seem to be in a category all their own, with their own solutions.

[phrunt]

2 hours ago, GB_Amateur said:

IMO, this is the key part of this kind of repair.  Unfortunately the product used in the 2nd video (Bison Plastic Adhesive) is not (easily) available here in the USA.  Anyone know of an equivalent product here?

I wonder if this would do the trick?

https://www.amazon.com/Weldon-10232-Medium-Bodied-Professional-Industrial-Grade/dp/B00K5PE9PW/ref=sr_1_3?keywords=abs%2Bglue&qid=1646073188&sr=8-3&th=1

 

[GB_Amateur]

That looks like it should do the trick.  The "with interference fit" comment in 'About this item' is misleading, IMO.  But one of the reviewers indicates it works for joining various ABS parts so it's not just for pipes/plumbing.

[phrunt]

yea, things like this are often cheaper in the bulk tins like these plumbers use, buy the same sort of glue at a hardware store in a little tiny tube for 1000 times the price 🙂

The reviews state they're using it for 3D printed ABS parts and it works well, so it should glue a 3D printed ABS coil stiffener onto the ABS ears very well.