Home made coil shells/housing/casing ideas

[nonkapo]

I think is good to have one thread where we can share ideas about what tomade the coil housing from. At the beginers stage it is beter to do something your self exploring own creativity and than after few builds to start using the better looking coil shells from the ebay or anywhere else.
There are few topics in the forum but spread around badly. So i'll try to summarize what i've got as idea from the forum and add my own discoveries.

So far i've seing the following coil casings:
1. Made of heat formed PVC pipe - nice, light and neat but a bit of a challenge to fit the coil inside;
2. Made of Frisby - nice but avaiable only for small diameter coils;
3. Made of dish for the flower pot - nice but what the wife will do after missing it ;-), the main challenge here is they rarely sell them separate from the flower pot, otherwise wide range of sizes avaiable;
4. 3D printer made - perfect as far as you can afford such a printer;

I miss for sure something but feel free to give your sugesstions

Here are mine:
I have no wide choise here but at least Carefour, Ace and Ikea are next to each other, so after nearly one whole day spend there see the following materials i get:

1.Laminate made serving dish from IKEA -(made in Bulgaria, probably in some of our ex military production factories). Comes in two sizes. Relatively light and stiff, but a bit tricky when drilling or cutting it - tend to crack(material smells getinax when angle grinder is used). The dish can be used as a coil former too.
2.Mammut child chair from IKEA - made in India from plastic. These are my last discovery. The upper part can be easily dissasembled. Unfortunatelly avaiable only in bright colours and one size.
3.Cake stand from ACE - these are too tick and after removing of the foil you figure out the materialis pressed cartboard. However still usefull for coil forming.
4.Coroplast board - stronger than cardboard but still easy to bend. I'm usig it only for experiments.

Will post some photos and links tonight.

[Qiaozhi]

You could also use the method described in Chapter 10 of Inside the METAL DETECTOR, and purchase an inexpensive coil cover. The top part can be made from either hardboard, plywood or thin MDF.

[bbsailor]

To make a coil housing do a web search on “plastic paint can lid” or “ plastic can lid”. Depending on the type you select to use, the groove that accepts the coil will need to be carefully measured to ensure a good coil fit.

Joseph J. Rogowski

[Andi68]

I always thought wood is unsuitable because it can absorb moisture ...

[Qiaozhi]

I always thought wood is unsuitable because it can absorb moisture ...

The wood was painted and the joints sealed. Seemed to work just fine during testing.
You could (of course) use a different material instead of wood.

[nonkapo]

To make a coil housing do a web search on “plastic paint can lid” or “ plastic can lid”. Depending on the type you select to use, the groove that accepts the coil will need to be carefully measured to ensure a good coil fit.

Joseph J. Rogowski

Thanks Joseph and George. I think about that sort of Lid, but it seam to me not stiff enough(they can be twisted easily). But also have advantages. They are superlight and can be sourced for free.

About the wood as material i think if you do not use it in water is good and unexpensive alternative.

And at the end the promised pictures:


Links to the materials:

https://www.ikea.com/sa/en/catalog/products/20382324/ it cost here around 6$;
https://www.ikea.bg/eating-and-drink...9441/90387422/ again 6$ 32cm, avaiable sizes are 32, 43, 56cm;
https://www.guineapigcagesstore.com/coroplast-on-sale - quite expensive new at 25$, however if you can source used one it willbe free.

[nonkapo]

Talking about the PVC made housing just ignore all the industrial heaters, hair blowers and so advices. It will take you much more effort to worm up equally the pipe as well as the risk of damaging it or unequally bending. You will save alot of time and have nearly perfect results if you have around 500grams of sand(thanks god desert is all around me;-). Put that sand in you wife's favorite pot and worm it up on the hot plate. Than do not forget the thick working glowes(ATTENTION HOT PIPE:-). When the sand is hot enough block one side of the pipe you wish to bend with shortest possible plugs(i use narrow parts of wine cork plug) so they do not disturb the bending at the ends. You can also just wrap the end with some duct tape. Than with a small funnel add the sand in the pipe. Keep in mind that the moment sand is in the pipe the last will start behaving like a cable or lets say snake. After filling to the top and close with the plug you have few minutes depending on the surrounding temperature to form the circle. In my case i just put the pipe in a bucket and it follows the ring shape perfectly. Once cool you can remove the plugs and sand from the pipe. Do not forget to clean it(here i have some iron deposits, silicates and oxides in the sand unwonted next to the coil).
I know i do not discover the hot water(hot water also can be used to bend PVC;-) but hope this is helpfull to the beginers. Will share pictures soon and show you how i wind inside my UTP basket coil.

[bernte_one]

https://www.thulemann.de/Hobby-h-s-u...te-/kat-11.htm

made from a flower pot, and one u-shaped Profile

hole Price is under 10€

[nonkapo]

Bernte Quick question - is the shaft plastic and what it is from? Especially interested in the telescopic mechanism(the lock nuts and screw).Thanks.

[Goaty]

interested in the telescopic mechanism(the lock nuts and screw)

My MPP detector is still a work in progress and recently I switched my attention from the electronics to the shaft.
For the telescopic section I originally had a 25mm worm drive steel hose clamp but have never been happy with having this chunk of metal relatively close to the coil, especially since the rest of the shaft was all PVC electrical conduit, so I set about finding an alternative.
While perusing the plumbing section of the local hardware “superstore” I came across a plastic joiner intended to connect a 3/4” threaded pipe to 20mm polypipe (black semi-flexible irrigation pressure pipe fitting - approx $au6).
To my delight it was an almost perfect fit to the 20mm and 25mm conduit and the twist clamping worked very well on the 20mm conduit. The only drawback being that it is a little bulky, but not overly heavy in spite of this. Also, it is necessary to remove a moulded ridge in the centre of the fitting so that the 20mm pipe can slide right through (used a half-round file for this)









I investigated several ideas for attaching the clamp and thought I should describe them in case anyone can adapt them on their own project.


#1 Glue 3/4” threaded end of the fitting to the 25mm pipe.
This is how I will probably end up attaching it.
The 3/4” thread is a taper thread and the PVC can only be forced in about half way so a taper will be needed by filing or sanding the conduit. I will probably end up using this method as the pvc plumbing solvent cement should soften and bond to the conduit forming its own thread. I don’t think it will bond to the fitting as this is probably polyethylene.


#2 Melt a thread into the conduit.
I experimented with making a tapered thread by heating a 3/4” brass coupling nut and screwing it over the conduit and allowing to cool. This was moderately successful and could be refined to improve it.









#2 Thread the 25mm conduit with a suitable 3/4” die
It should be possible to cut a thread onto the conduit if a suitable die is available.


#3 Make a clamp out of the 3/4” threaded section of the clamp only.
A cheaper alternative, especially if the fitting I used is not readily available, could be to use any other plastic fitting which has a 3/4” F taper thread. A suitable M thread will need to be made on the end of the 25mm conduit then 3 or 4 longitudinal saw cuts made in it so that it will clamp down on the 20mm pipe when screwed on. I tried this using the back half of the fitting and it seemed to work OK.


P.S. The 20mm conduit is a fairly loose fit into the 25mm – to stop it flapping around I softened it with heat and forced a suitable sized wooden dowel in to slightly expand it.

[qute1]

Back to upvc plumbing pipe ring coil covers if you use 22mm thick wall you can just (if strong enough) bend it so long as 10" or so no heating required and just plop it into a tee and tighten down and it will develop a "set" within a few hours i have done 4 coils this way (and 3 with even smaller diameter 15mm?) and works fine and no wrinkles or kinks like i used to get by heating wider (28mm) pipe.
After a couple of hours you can undo one end to allow feeding the cat5 plenum through more easily and it just does right up again. Simples.

[nonkapo]

Nice solutions all. Qute1 if you use hot sand you'll never get wrinkles or kinks as it worms up the PVC equally.
Goaty i was thinking of buyng one of these standard golden mask links(https://www.goldenmaskdetectors.com/...?id=28&lang=en) but after seing your post i have another hope.

[Tibuck19]

I 3d print my coil housings

[qute1]

Thank for the tip Nonkapo i will try hot sand but i only used to get wrinkles and kinks if i tried to heat bend thick pipe into too tight a circle seems to depend on the type of pipe too i now use hp waterpipe (thick grey stuff) and no more problems.

[nonkapo]

No time for a videoclip but when free i'll try to upload one.