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It seems to me, that with the advent of cheap 3d printing, someone should design some coil housings to be printable in ABS. Because of the limited printer size, they would have to be printed probably in sections, with a simple snap together ends, that could be glued with ABS black cement that is sold for solvent welding (cementing) black plastic ABS plumbing pipe. They would need to be printed such that when the top half and bottom half were assembled, and mated, that the joints holding the pieces of the upper half and the pieces of the lower half were off set significantly from each other so as to not have weak spots in the coil. I would envision the ends composing some interlocking fingers, with an additional clip like male piece on one end, and a matching female piece on the other end of each piece. Seems like Spider type coils would be fairly easily made this way. Where the wires go should have enough room to move them around enough to null The ears could be made for specific models of detector shafts, or a shaft end could also be 3D printed.
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First of all I am new to this forum so hello everyone!
I have designed and printed out coil housings and all the other parts required for a detector build as you talked about here, I designed all the parts to be 3D printer friendly and to fit on a standard 200mm x 200mm build plate, by printing the coil housing at 45 degrees I was able to just squeeze in a 9.5 inch oval coil which is about the same size as the Minelab705 standard 'DD" gold coil, I designed the coil housing to accommodate either mono or "DD", so far I have only printed it in PLA plastic which seems to be quiet strong and rigid, I am still building my first detector and may further develop these designs. I will post the CAD pics now and try and upload some photos soon when I take some.
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Some other parts I have designed and printed for my detector build which printed well, elbow support, pole handle, and also a coupling to attach coil housing to pole, another thing that printed out very well was a sand scoop, the sand scoop worked very well for about 3 hours of beach work and then broke suddenly, I not sure I will succeed in developing a scoop that is 3D printable and durable enough to last long term until maybe advances are made in 3D printing as it suddenly let go along the print lines, however I think the detector parts will be plenty strong enough with maybe the exception of the lugs on the coil housing which may be the weak point and need further development, field testing will begin as soon as I finish my first build soon.
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Hi UP interesting stuff you have been printing, what printer do you have ?
From the little bit I have read ABS is much stronger and durable than PLA
your sand scoop may be strong enough for very dry sand and very short handle
it will be very interesting to see when you test it., But if it breaks just print another one
I am interested in getting a printer to have a go at making coil housings.Comment
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The printer I am using is about the cheapest available, the Reprap Prusa, cost about $480au plus about $26 per KG for the plastic rolls. I have not done a lot of work with ABS at this stage but found ABS a lot harder to print with for the beginner, ABS needs a lot more heat in both the nozzle and print bed and on my printer I have temps dialed up to max to print with it, I don't know if it is just a matter of printing another one if it breaks, for eg: the scoop print was a 10.5 hour print and uses about $4 in plastic so its got to last more than a few hours, I may try adding a rib to the scoop design and printing it in ABS but I am not confident it will last, I was using it in dry sand when it broke after striking a drink can and a rock. the main coil housing I think from memory was also about an 8 hour print and even the shaft handle about 7 hours, not that time is a huge deal as you just start the print and then forget about it until it finishes, I often start a print before going to bed and wake up in the morning to a finished print. I have taken a few photos of the prints which I will add below and also the printer.
I have just finished soldering up my first Surf PI, crossing my fingers it works, just have to wire up the trim pods, battery, then make a coil, I was tossing up if I should do a DD or mono coil but after reading some threads on this forum I think it might be best to start with a simple mono coil and if all goes well I can try a DD and the board mod at a later stage.
Buying a 3D printer has been a really satisfying thing to do, I would recommend it for any home hobbyist with an interest in that sort of thing, to make it come alive you have to learn how to create 3D models in CAD but if you can do your own modeling then sky is the limit just about to what you can create at home.
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I might add the reasons I choose a Reprap Prusa plus some pros/cons if this is helpful to anyone thinking of buying a printer
Pros: Cheap, Decent build size 200mm x 200mm x 120mm height, easily upgradable to a bigger build size with a handful of cheap threaded bars and some 3d printed parts, fully upgradeable to latest components, nozzles etc, cheap replacement parts and readily available.
Cons, not a very rigid design which can effect print speed and accuracy (but this can easily be upgraded and fixed), wiring not ideal and may need periodic replacement, twin motor design on Z axis not ideal and can cause problems especially if one screw locks up or misses a step (keep screws well lubricated with grease to avoid this), print bed a little cheap and hard to level (but this is upgradable/fixable), screws/nuts etc can vibrate loose while printing (to avoid this check and tighten all screws regularly especially stepper motor pulley and drive screws)Comment
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totally blown away.Originally posted by The Urban Prospector View Post
Would you be willing to upload the files for the coil, the handle, the arm cuff to this forum? I don't know enough about 3D printing to know what software is standard etc. What program did you do the design in? What is the most flexible export format.
The idea I had was to build the coils in 4 sections with lock together tabs. When printed in ABS, and you use ABS cement, you can glue the joints, snap lock it together, and have a strong waterproof housing. That is, you design it so the 4 pieces will lock together solidly with tabs or snaps, then put the ABS cement (black, and used for trailer plumbing in the US) on it and snap it together. AFter it sets, you can coat any missing areas. This will solvent weld the seam.
I would be looking also for a handle similar to what you did, but with a meter housing kind of like the whites, or ace 250, that would have a place for 8 AA's (I'd put them in the vertical handgrip). It should be capable of being clamped around a 3/4 inch electrical conduit or if you leave the bottom clamping plate off, be capable of being screwed to a box. Which would mean that it should have a tang on the bottom.
Please PM me.Comment
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hello urban prospector
i had not read all
but could you write how much time you need to print the single parts with which settings (infill etc..)
would you allow me to post the pictures on german detektorforum
printing parts a think i would really love to to, but at monet and have to re organize my whole house and also soem of my hobby machinesComment
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Bernte_one he said the the scoop print was a 10.5 hour print and the shaft handle about 7 hours.Comment
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The models were all designed in Solidworks, G-code compiled in Cura and then I run the G-code in Pronterface, Cura and Pronterface I think are both freeware and probably come with most 3D printers. Uploading files is something I am still thinking about, I already made a decision not to upload to public model download sites for a couple of reasons, one is I don't want to see my models, printed parts and intellectual property up for sale on Ebay by anyone other than myself, this has happened to me before and really hurts, the other is these are all high resolution models and the STL files mostly range between 300MB and 750MB in size and with an upload limit of 80kbs I would be uploading for a long time. Now I may consider sharing actual CAD files which are much smaller with individuals who would guarantee personal use only, format may depend on the person and what CAD package you run, something like IGES or DXF might be appropriate.
Your idea of a large coil printed in 4 quarters sounds challenging, I designed what I believe may be the best goldpan in the world, its around 350mm in diameter and so I cut it into 4 quarters with each quarter only just fitting on the print bed, however I have been reluctant to hit the print button as each quarter would take about 10 hours so its a 40 hour print. I am considering building a bigger printer with 400 x 400mm x 300mm high capacity which may be a far better solution. Something to consider is that 3D prints can be slightly porous and hents not waterproof, its something I maybe want to explore in these forums when I get to it and what options there may be to make these prints waterproof, like maybe a layer or coating of silicone or something. The handle and elbow support I have designed is to suit 1" inch or 25mm upper tube and the lower tube 27/32" or 21.5mm PVC tubing. I have designed a control box for the Surf PI which works great but needs some tweaking with sizes as the board didn't quiet snap in like it was meant to, its just a simple rectangle box with all the holes for trim pods etc printed in, its designed to suit the standard 3x18650 battery holder which screws in above the board.
I would suggest to download some CAD packages and have a play around with your design idea's, use them as a learning project, certainly some packages have good tutorials and you can be designing your own models in no time at all.
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Most of the larger parts I think ranged from approximately 6-8 hours per print, I didn't keep a record of actual print times, the handle due to its shape had to be printed on a raft, all other prints just had about a 10 line brim to stop edges curling, I use a 0.5mm nozzle with layer height at 0.2mm, used 1mm shell thickness all around and between 20%-25% infill density depending on the part.Originally posted by bernte_one View Post
I am OK with you posting pics on another forum, maybe send me a link to it!Comment
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Just for interest what size do they compact to useing 7zip ?STL files mostly range between 300MB and 750MB in size
Is that from a kit ?I am considering building a bigger printer with 400 x 400mm x 300mm high capacityComment
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Originally posted by 6666 View Post
I just tried zipping some files and they actually compact quiet a lot, for eg a 180MB STL compressed to about 60MB, still pretty large in size but I can also reduce the size's much further than that by reducing the tolerance (resolution) and cutting down the amount of triangles in the STL model. The actual CAD files are way smaller, usually only around 1mb or less, another option is just the G-code files which range from around 1MB to 10MB, they might compress further to but unsure whether the different printers out there may need slightly different code and settings which would then need to be manually edited.
No I would just import the parts from China and build my own printer, I would probably make a very rigid welded steel tube design, on that list you posted a link to, (which is a good list by the way) there is a couple of large capacity printers with around 400 x 400 capacity, but the price on them is pretty steep, $5000 -$7000, I would use a similar design in cheap MS tube, I think I could completely DIY the same capacity for under $1000au, another option is to buy a $500 Reprap and use that as a donor, it would then need bigger screws (probably ball screws), a bigger wiring loom would need to be made and then I don't know how big they make the heat beds but 4 x 200mm $30 heat beds could all be mounted on one plate with one large sheet of glass over the top, (not sure about the electronic hook up for that but I presume it wouldn't be to hard). I have no immediate plans to do this at the moment due to other urgent issues more important, still just an idea.
Finished my Surf PI project and tested it on the beach last night, quiet impressed, within an hour I found $6 and a rare lightly circulated 1929 Half penny which would be worth a bit if not for corrosion, plus a crap load of junk lol, but it punches through the heavily iron infested salt water area's where my Minelab 705 has a total fit, it could do with some fine tuning and playing around with coils, at the moment its getting coins and gold rings at around 6" to 8"inch max, I don't know how much better the Surf PI can go but I would like to get up to a foot if that's possible. Will post some more pics of the finished project soon.
Here is a pic of something else I printed which worked really well, a coil winding jig.
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Just posting the finished pics of my fully 3D printed Surf PI 1.2, it came out really good and functions as intended.
After testing I think I will do a bit of tweaking to most of the parts, coil housing I want to completely re-design more like conventional coil building methods, I want to make the next coil fully water proof, and epoxy filled or something with less plastic used for the print, the current housing was mainly a test model, handle could be angled further forward maybe another 10 degrees, Surf PI 1.2 board housing needs some slight tweaks, board didn't quit clip in properly and I accidentally made it left handed so the knobs keep hitting my body and adjusting themselves, I might mirror image the current case or relocate the knobs, and the elbow support needs thickening around the strap slots or deleting the strap slots altogether because they may never be strong enough printed in that direction, screw on slots printed in a direction that makes them stronger might work. I even printed out the little plastic thumb nuts for the case, tube plug, shaft adjustment and locking screw, everything accept the actual shafts which was taken from an old adjustable mop I found in my garage and a piece of PVC tube for the lower shaft. Overall I am very happy with how it came out and I couldn't imagine a better way to build home made detectors, the best thing about the detector is its well balanced and light as a feather, My Minelab 705 feels like a brick in comparison. Something strange I noticed is that when I snapped the 2 housings shut around the coil I lost 2" -3" inches in detection depth, attempts at re-tuning failed to recover any lost depth, I am wondering could the 3d printed housing be slightly conductive and working like a shield? I had no success with ally foil shield so I removed it as that also took 3" inches off the depth.
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