3D printed detector

[The Urban Prospector]

Well done Tec, nice job!
I have also recently finished a complete 3D printed detector build which came out good, functions as intended, I am about to start tweaking my design and make it even better, I can't imagine a better and easier way of making home made detector especially when you become competent at making 3D models in CAD.
I noticed we had some similar idea's like our housings and some totally different idea's!
Here is a pic of my project.
http://www.geotech1.com/forums/attac...1&d=1421816670
And lots more pics and info in this thread.
http://www.geotech1.com/forums/showt...684#post200684

[The Urban Prospector]

Hi Tec how do you think your 3d machine would go makeing the former for this type of coil ?
http://www.geotech1.com/forums/attac...1&d=1414104068

Hi 6666 I noticed Tec didn't reply to some comments so thought I would answer, 3D printing is a perfect solution for things like the 'spider coil", I intend to try one myself soon, and I can do it in an oval shape to or any shape for that matter, as long as the coil is smaller than my 8" print bed, however it could be done in quarters for a bigger coil, things like than can be drawn up and start printing in like 15 minutes, my coil housing used about $6 in plastic and doubt more than about 50 cents to a dollar in electricity, have not noticed any increase in my power bill since I started 3D printing.
In regards to PLA plastic from what I have read and been told it won't just start bio-degrading after a few months, it needs chemicals, PLA was designed with artificial implants for the human body in mind, like bone implants that break down as the bone heals and replaces the implant as the implant degrades, its needs to be subjected to body fluid or chemicals that mimic body fluid to start the process, none of my models printed 8 months ago when I bought my printer have any signs of degradation, how salt water affects it well time will tell with my testing, PLA has some great positives and is a very interesting plastic to work with, it seems more rigid than ABS, but yes can also be very brittle especially along the print lines, they are also developing better grades to like hemp fiber reinforced PLA, Recently a conductive ABS was released which may be useful for self shielded coils, board casings and things like that, I read it was designed to actually print circuit boards into the model as its being printed. Cold printing heads are also being developed which could be used for printing silicon, chocolate and other materials. If PLA or ABS isn't strong enough then you can use your 3D models in a different way, like using your 3D model for sand or lost wax casting in various metals, or maybe you can use the model for vacuum forming?, be much easier than making a wooden model, and if that won't do you can just take your CAD model to someone with more expensive printer and get them to print it in titanium dust which is then sintered into a solid, probably get your wallet out for that sort of thing to. Owning a 3D printer at home really revolutionized my home work shop, one of the best tools I have ever bought. Next goal would be a CNC router or milling machine at home to, maybe even a laser cutter would be a good DIY project.

[6666]

Thanks for the info UP, I do plan on getting one of these 3d printers they look a lot of fun, it would be so much easier to print a coil former than spend a long time with the jig saw, just downloaded sketch-up so will check that out to see if it makes any sense, how is the sand scoop holding up ?

[The Urban Prospector]

Thanks for the info UP, I do plan on getting one of these 3d printers they look a lot of fun, it would be so much easier to print a coil former than spend a long time with the jig saw, just downloaded sketch-up so will check that out to see if it makes any sense, how is the sand scoop holding up ?

I think about the sand scoop a lot, its on my thinking bench lol, I still don't think a decent size 3D printed sand would work unless printed in titanium or something, I was watching Fredrick Barnes on YouTube with his plastic shovel turned into a detector invention and he snapped about a 1.5 inch (hard wood?) handle on that thing which gives you an idea of the stress involved on a beach scoop, then I met a guy down the beach the next day with a popular brand stainless steel scoop which looked fantastic but after 2 hours in the water he was complaining about how heavy it was and that he was tired and going home, and no doubt a scoop that size would have to effect the field of his detector as well, so it reinforces my idea of a non metal light weight beach scoop, also while I was testing the 3D printed scoop I made the non metal design had huge advantages over metal, mainly because you can swing detector over scoop without washing and check you have the item, which is probably pretty obvious, but it has to be nearly as strong as steel, so I keep going back to maybe carbon fiber as the only obvious solution, maybe its time that I learned to work with carbon fiber, that might be a good topic to start a new forum, I have also noticed metal detector companies have been using carbon fiber on detector shafts for a while now which also makes sense.

[Davor]

How about stainless steel?
Recently I "tested" airport security door with my wrist watch that is made from stainless steel. Not a beep.

[The Urban Prospector]

How about stainless steel?
Recently I "tested" airport security door with my wrist watch that is made from stainless steel. Not a beep.

That's really strange, I know my stainless steel Seiko watch has triggered both the airport and courthouse door detectors, and my new Surf PI detector has already found 3 SS spoons and a pair of scissors on the beach during testing, my Minelab 705 I think will ignore most SS objects depending on the discrimination level but not all, a lot of SS will read as iron depending on the grade, there is many different grades of SS, could the airport security detector have had its discrimination on? lol surely not? But even if your discriminating against something its still effecting your field, masking and reducing signals on other items in the surrounding area.

[The Urban Prospector]

That's really strange, I know my stainless steel Seiko watch has triggered both the airport and courthouse door detectors, and my new Surf PI detector has already found 3 SS spoons and a pair of scissors on the beach during testing, my Minelab 705 I think will ignore most SS objects depending on the discrimination level but not all, a lot of SS will read as iron depending on the grade, there is many different grades of SS, could the airport security detector have had its discrimination on? lol surely not? But even if your discriminating against something its still effecting your field, masking and reducing signals on other items in the surrounding area.

After writing the above comments it had me wondering what type of detectors airports use, VLF or PI? And say the guy behind you is carrying lots of metal, like a Mexican hat lined with foil, a suit of armor and he rests an aluminum beach scoop against the airport security detector while its scanning you, would this mask the small items you are carrying like your watch? maybe airport security is not so foolproof, I mean there detector technology wouldn't be anymore advanced than what we use on the beach, scary thought!

[Davor]

Most security systems are targeting suckers like you and me, and it is far from fail-safe. For some odd reason people feel safer when properly intimidated. Making an airport sensor that works on psychology most of the time is much easier than making a detector that has to identify metals from production faults.
My point with stainless steel is a disproportionately weaker response even for larger objects like scoops.

[Tec]

Hi,

Sorry for the late reply.
It would be be great, would need to make it in a few pieces (because of size).

I have another chance to work on the detector. And I have ordered some Conductive filament. Apparently it is 10k ohm per cm, so I am going to make a shielding former for a bundle-coil..

[Tec]

Yes,, I have used PLA and ABS. PLA is easier to work with and non toxic fumes (smells like sugar) and more rigid, (consistency and weight of bamboo) I have painted the parts with epoxy. I will see how long they last.
Otherwise I would use ABS for unpainted parts outdoors.

[6666]

Had a bit of a look into these 3d printers and was told if you want to print ABS the printer needs to be in a box because the plastic fumes slightly.

[Tec]

You could design something that could be printed and then reenforced with epoxy..?
Here is something I printed yesterday , it is 1cm hexagons, separated by 0.5 mm gap. When I brush epoxy on it , it becomes quite strong. How strong I don't know yet...

[6666]

Interesting, I was thinking about trying to print a riffle tray for a river gold sluice, do you think PLA would hold up in water.

[Tec]

Good idea, I'm not sure how long PLA would last, I haven't used it in water yet. I think it breaks down over time. It should last a for a few sessions at least..

Regarding ABS, the printer I got is in an enclosed box (flashforge) , when printing ABS the door is kept closed, when printing PLA the door is open.

[sinclairuser]

brushing with acetone consolidates the print, it smooths out print lines and gives a shiny finish too.
@ tec, look into nylon filament, very strong!, i got a small sample sent form makerbot( very small), but it was enough to do a print to test.
over the next few years there will be an explosion in filaments, all the printer manufacturers are doing something different its exciting.