Help- can I build a large 4x8 detector coil for meteorites?

[FarmDectector]

First post... looking for help. Has anyone built a large detector coil like seen on the meteor men show where a coil is mounted to a pvc frame.

Coil appears to be 4 x 8 feet.

I'm looking to pull this behind an atv in a farm field.

Any ideas?

 

[FarmDectector]

Op here. Above is a picture of what someone else built that is similar.

Appears custom made?

What ideas do u have to contruct that coil?

 

[FarmDectector]

Or, can people point me to sites or sources that can answer these questions?

 

[JWalker3]

Building a detector coil is a lot more than just fitting some pvc pipe together and running a loop of wire through it. It would have to be an exact length of wire for the frequency of the detector it will be connected to. I'm fairly sure that not any metal detector can handle that size coil. Unless you are an electrical or have the assistance of one you have a big hill to climb.

 

[atomicbrh]

Building a detector coil is a lot more than just fitting some pvc pipe together and running a loop of wire through it. It would have to be an exact length of wire for the frequency of the detector it will be connected to. I'm fairly sure that not any metal detector can handle that size coil. Unless you are an electrical or have the assistance of one you have a big hill to climb.

As JWalker3 says, unless you are a electrical engineer specializing in this field, you are going to throw money away on something that does not work and costs you many hours of endless frustration. The pvc pipe will not stay together even on the smoothest of fields. The control box will require real expertise to build from scratch. The surface coil cannot have wheels unless the axle and wheel is totally plastic. Something that slides like a sled seems to be the only solution. The pipe cannot take that abuse for long. Your best solution is to buy a used complete machine from:

Formtech Services of ID LLC
Bill Swearingen
43 Shoemaker Ln.
Horseshoe Bend ID 83629

Questions, technical support or orders
Bill 208-995-1749
Rod 307-690-8857

Formtech makes the hotfootrug which is a pull behind sheet detector.

http://hotfootrug.com/Hotfootrug_Metal_detector.html

Here is the link from the nugget shooter forum for this same sort of homemade device:
https://nuggetshooter.ipbhost.com/topic/30745-metal-detector-sled/

There are some specifics about coil design with the pvc pipe in that discussion.

 

[FarmDectector]

Thanks. I saw the hot dog sheet that drags behind. I agree the pvc pipe can break.

I'm following up on the other link. Looks interesting.

Thanks.

 

[atomicbrh]

Thanks. I saw the hot dog sheet that drags behind. I agree the pvc pipe can break.

I'm following up on the other link. Looks interesting.

Thanks.

I have another idea. If you decide to go forward with this project, why not use a sheet of Kydex instead of the pvc pipe. Kydex comes in 4 foot X 8 foot sheets, is easily sawed, drilled and bent/curved but it is still very tough and abrasion resistant. Over the decades I have bent Kydex at sharp 90 degree angles and put a gentle curved radius on it.
All without any kind of heat. Used it for chain guards and belt guards on all kinds of equipment. You can drill holes in it and hook a rope to it to pull behind your atv. You can ziptie your coil to the top of it without having to cut or glue the many pieces of pvc pipes, connectors and corners. You should be able to mount everything by just drilling holes. Kydex comes in gray or black and a great variety of thicknesses. It seems to have the properties of Delrin but in sheet form. It will be easy to put a slight bend in the leading edge so that it rides smooth like a sled. Kydex is expensive if you buy it from just any retailer but if you shop around you may be able to buy a surplus sheet for pennies on the dollar. The other alternative would be what we call "rubber glass". Rubber glass is used by race car builders to make car noses that can take abuse. It comes in a roll and is cheaper than Kydex but it does want to retain that roll shape and not lay out flat. It is very long but probably too narrow for your application. I do not know the trade name of rubber glass but any major shipping race car retailer will stock it.
(If it was me, I would simply put a knot in both ends of the pull rope and even use high strength zipties to attach the two ends of the pull rope to the Kydex. That way if you hit a big dirt clod, root or obstruction, the ziptie will just break and none of the rest of your device is broken. Also the zip tie will not interfere with your coil like bolts.)

 

[FarmDectector]

I need to look into that. I like your idea.... it won't break like pvc will

 

[amc rulz]

Sure! Here’s one that I built… Drag half this across a field.

 

[maxxkatt]

one guy hooked 4-5 gold metal detectors on the back of a small trailer. Set the sensitivities, etc so as to only pick up large nuggets. Wired all the audio back to his head sets and set out in the desert.

Not sure when but eventually he found one of the largest gold nuggets in the western US. I may be getting parts of the stories mixed up, but the 4-5 detectors fastened to the back of the small trailer was correct as I remember it.

Maybe try something like that. You could hook up 4-5 AT Pro's and they would do the job for you.

A lot simpler than trying to build your own control box and coil.