3D printed detector

[Tec]

Beautiful

[The Urban Prospector]

Here is the safety data sheet for ABS, its pretty harmless material, the only thing it really mentions is it could irritate the nose and throat during processing but I have never seen anyone affected by it in the 32 years I have worked in the plastic industry, the only health hazard really is that its recommended not to breath in the dust, not an issue for 3D printing, a respirator should be worn for handling raw granules or during the grinding and granulating of reject parts for recycling but thats about it really.

http://www.cityplastics.com.au/site_files/687/pdf_files/abs%20msds.pdf

[The Urban Prospector]

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.

I don't believe this at all 666, sounds like misinformation to sell you a more expensive printer, the fumes from ABS are very mild and I can barely smell it in my house while printing, and PLA smells like sugar or corn syrup which has a pleasant smell, I have spent most of my career working in molding shops using all types of plastic especially ABS and if ABS was toxic I would be dead by now, I think the only plastic that puts out really noxious fumes is Acetal, this stuff will sting your nose and eyes while its being molded, however I seriously doubt we will be printing in Acetal to quick as its also explosive and for that reason I doubt it would ever work in a 3D printer.

[The Urban Prospector]

PLA stands up fine in water, it only breaks down when subjected to body fluids according to what I have read, however one note on this is I noticed one of my PLA rolls has become quite brittle, I suspect that its because I do not have a range hood or extraction fan in my kitchen and its been subjected to a fine layer of animal fat like everything in my living area.
I have been printing in ABS lately and its not necessary to print in a box, well at least not during an Australian Summer, Winter might tell me a different story.
My last coil I printed in ABS and is virtually unbreakable, its very strong flexible material, its epoxy reinforced to which makes it more rigid and water proof.
My printer is down at the moment with a blocked nozzle, when removing the nozzle I found the nozzle temperature sensor wires were hard wired to the nozzle somehow and I broke these wires, still scratching my head about this and how to fix it again, might have to throw it in the bin because if there is a sensor in the nozzle I don't think there is any way I will remove the sensor to re-solder the wires, really it should have had plugs fitted to it but I guess you get what you pay for, to complicate things further the design of my Prusa nozzle is nothing like any other Prusa nozzle I have seen so ordering spare parts might not be that easy either, I may have to manufacture my own nozzle but this is also not desirable as putting a 0.5mm hole through stainless steel is not so easy especially on my antique hobby lathe.

[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.

[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.

[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]

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]

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]

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.

[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..

[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.

[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!

[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.

[Davor]

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