New Prototype Detector - My First Analog Attempt

[Johnny Crunch]

On 12/31/2020 at 1:25 PM, GB_Amateur said:

I'm not a gardener which leads to this question.  Is potting soil just natural earth that has been dug up and put in a bag?  Or is it specially prepared organic material selected to 'feed' plants?  If the former then I agree, but the latter (depending upon if natural soil is included) may not contain the ferromagnetic minerals that affect real life detecting.  It's pretty easy to just bag some dirt from the backyard.  I've done that with ZipLock freezer bags.  You can fill them so that they have a more/less consistent thickness.  Mine are quart volume and when filled, sit flat with a thickness of approximately 1 inch.  Then I stack them.

Yeah, I think you are right, GB. Potting soil is probably too unlike normal detecting conditions. I seem to remember something about it containing coal dust to make it darker, which might add another complexity to using it. My initial thought was it could be used as a standard for anyone running such a test, but that's a specious assumption on my part— anyone might be better served using the actual soil that they have to deal with normally, mineralized or not... Thanks for the constructive criticism!

[Joe D.]

Sun-Boy 

   Seems like you have a pretty good handle on your design and implementation! I don't think any of us could have guessed you were so far along on your prototype when you got here! Congratulations! I really like the carbon fiber over the aluminum! Keep up the good work, and keep us posted! Interesting to have a window into the birth of a new detector design! Thanks for sharing!??

[kac]

There is also Shapeways, might be a bit more competitive to 3d Hubs. When 3d Hubs first started it was everyone under the sun with a 3d printer then they tightened up the requirements for quality assurance and now it seems only the big shops are supplying.

You could check out Stratasys directly for fdm part they offer printing services. Alternatively if you don't require high temp fdm parts like the nylon series you can take a look at the Flashforge units. They have a dual extruder for $879 delivered and upgradable to high temp. Dual extruder so you can print a pva support material to prevent your part from distorting or failing during the print process.

I'm pretty good at spending other peoples money ?

[Sun-Boy]

Yeah Joe, I've been dabbling with the design for several years, it's just now gotten to this point, you know, life happens, you step away from it, may not get back to it for months or years.  I can't do everything else I used to, but this thankfully is keeping my brain busy.  And I'm surprised how light the parts are coming out, aluminum is really pretty, and I wanted to go with it, but the price is just to high.

I haven't used Shapeways, but I'll definitely look into them and get a quote on my next parts.  Yeah I used 3d Hubs when it was folks in there garages and you didn't always get what you were expecting, but I knew that going in, so I would take my warped coil forms and do my best with them, lol.  I'm not interested in 3d printing enough to  buy one, I know me, I'll do a few prints and then the machine will sit idle, better to send out for my parts.

I've gotten my mechanical parts in for the housings, and interconnects, as well as the new main electronics pcb, I'll update the thread later tonight with some new pic's.  Still waiting on my components from Digikey, and then the soldering begins again.

A buddy of mine who is a software guy, really expert with embedded micro's dropped by yesterday, he wanted to see how it was going.  I walked him through the design, and he gave some idea's, I was amazed at how well the unit would see his gold wedding band.

...so it continues, hope to upload some pic's tonight...

[PimentoUK]

As an electronics engineer, I have to say your project is very neat and well planned.

Are you a member of Carl & George's "Geotech1 Forum" ? It's a useful resource, if nothing else, and there's always the angry Lithuanian/Bulgarian/ etc guys to keep the place entertaining.

Re: the coil. I would advise designing your machine to work with a known good commercial coil, then when you're confident it's working OK, consider making your own coil. Your chances of success are much improved that way.

[Chase Goldman]

3 hours ago, PimentoUK said:

As an electronics engineer, I have to say your project is very neat and well planned.

Are you a member of Carl & George's "Geotech1 Forum" ? It's a useful resource, if nothing else, and there's always the angry Lithuanian/Bulgarian/ etc guys to keep the place entertaining.

Re: the coil. I would advise designing your machine to work with a known good commercial coil, then when you're confident it's working OK, consider making your own coil. Your chances of success are much improved that way.

I second Pimento's call out of the Geotech forum as a tremendous resource for detector DIY'ers.

[Sun-Boy]

Getting some parts in:

Display housing, main pcb and other miscellaneous parts.

Display housing parts and display pcb

Display board in housing

Internal frame to hold pcb, batteries, and other connectors

Inserted into the carbon fiber housing, with front feet attached

Display frame laying on top of the main tube housing

Coil form

Wire attachment area and cover

 

Spent some time today cutting carbon fiber tube, doing a little spray painting, nothing major.  I'm not looking forward to cutting out the openings on the tubing without a decent mill or cutting tool, only two of the drilled holes will be showing, everything else will be covered by frames, so no jagged holes will be showing - but this stuff isn't the easiest material to work with.

About Carl and George's Geotech1 Forum, is it on this forum somewhere?  I would like to check it out.

...we'll see if I'm able to get anything done tomorrow...

 

 

[TallTom]

It's a collection of subforums, here:

 

https://www.geotech1.com/forums/forum.php

 

[Sun-Boy]

Tom is it tricky to register at the forum?  I'm having some trouble.