Amateur Radio, Electronics Workbench, Machine Shop, Recumbent Bicycling

TinyTrak3+ Trimpots: Not All Are Created Equal

I designed the GPS+Audio case around the TinyTrak3+ board in my radio, which has two square, blue-plastic trimpots. The case worked fine for that board. Then I printed the case for the next bike and that TT3+ didn’t slide neatly into place:

TinyTrak3+ trimpot overhang
TinyTrak3+ trimpot overhang

Turns out that one of the three TT3+ boards uses plastic trimpots and the other two have metal trimpots bent to fit the existing holes (so they’re not a drop-in replacement), with a very slight overhang beyond the edge of the PCB.

So I attacked the case with some riffler files and carved a notch above the PCB slot. No pictures of that, lest you think I’m a butcher of lovely 3D printed objects. Next time: build the notch into the case’s solid model.

Most likely, this is the only instance of those pots causing anyone a problem…

8 thoughts on “TinyTrak3+ Trimpots: Not All Are Created Equal”

  1. Nice photo!
    Now, totally off-topic, how do you get these great close-ups, Ed?

    Nice work on the Woo-Zhun, also…

    1. how do you get these great close-ups

      The Canon SX230HS has pretty good macro capabilities and I have closeup adapter lenses for the Sony DSC-H5 and DSC-717, but the real trick is ruthless cropping. Here’s the original image from the Canon, crushed to reduce the display size:
      TT3 trimpots - uncropped image
      I’ve standardized on 750×562@150 dpi for the blog pix (not too gritty, not too bulky), which means a dot-for-dot crop covers the middle 18% of the image from the Canon and 28% from the H5. That puts the camera far enough away from the subject that I don’t need exotic flash technology to get light around the snout of the lens turret; good lighting counts for everything.

      Plus, I take a bunch of pix and only show off the ones where most of my mistakes cancel out …

      Woo-Zhun

      Or Oh-Sheng or Oh-Shung or whatever… [sigh]

      1. Nice!!! My daughter is an (old) college age student that is getting her art degree in basically “concept” art and CGI, altered photography. We will be purchasing another better digi-cam, looking for an easy to use SLR.

        And lastly, my son and I (he’s also college age, go figure) were “discussing” the viability of 3D printing and I said the plastics were fairly tough but he doubts this… I also theorized that epoxies could be utilized, making strength very high.
        How has your plastic printing stood up?
        I saw the CO2 cartridge thing-o-matic, was it pretty strong?
        Sonny Boy doubts that metallic 3D printing would have the strength needed for automotive use…
        I cited the GM composites program for intake manifolds, is that Check or Mate? :-)

        1. an easy to use SLR

          I like the Sony DSC-H5; it’s far less bulky than a DSLR, has a great zoom range, accepts 58 mm filters, and has all the manual controls I need. The things doesn’t produce RAW files, which is probably a fatal flaw for anybody doing serious photography, but the JPGs suit my needs pretty well. The newer prosumer cameras probably do all those things much better.

          A DSLR presumes you’ll be stocking up on lenses, which definitely isn’t my use case! [grin]

          the plastics were fairly tough but he doubts this

          I printed the Longboard Lighting case at 25% infill with only one shell (which works out to two, the way Skeinforge does the infill) and I can’t deform it at all. That’s with a 5 mm wall and no top or bottom.

          Smaller / thinner objects seem more bendy than molded ABS, so it’s probably not suited for extreme service where you must know the exact ultimate strength. On the other hand, those year-and-some old bike mirror mounts continue to work perfectly, the blinky brackets haven’t budged, and the fairing mounts haven’t cracked or bent (the white plates are sun-bleaching, though, so they won’t last forever).

          For my simple needs, 3D printed ABS is perfect…

          Can’t say anything about metal or ceramic powder or anything else. Can’t afford ’em, either. [grin]

      2. Ed, I’ve moved from a Nikon D80 (too heavy!) to a Sony H9.. found that it not pocketable so I got a hx-7 now a hx-20. I carry this in my pocket on all my walks and drives. Great wide angle and close ups at 18MP.

        1. I carry this in my pocket on all my walks and drives

          And you never again say “I wish I had a camera!”

          Quibbles about the megapixel race aside, all the pictures are good enough and you have the pictures, which is what counts…

        2. “Quibbles about the megapixel race aside,…”

          My grandpa used to compare radios according to their weights. Something to do with the power supplies of the radios of the era? Maybe could be applied to cameras too (heavy optics = high quality)? This camera weights 1.5 x more than its competitors, but does not boast with megapixels.

          http://www.fujifilm.com/products/digital_cameras/x/fujifilm_x_s1/

          1. Something to do with the power supplies of the radios of the era?

            Makes sense to me: more iron in the transformer = more power-handling capacity = better audio.

            They don’t call ’em boat anchors for nothing!

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