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3D Printing: Bottom Assembly

Now that you have all the parts generally cleaned up, it's time to assemble the bottom parts. This is the most complex assembly, so be patient here. mistakes will cascade into the rest of the build.

Step 1: Check Screw Hole Size

First, you need to make sure your 4 screws pass through the holes in the north and south screw holder parts. You can use a soldering iron, or various dremmel tools to do this, just be careful, as both tools can easily damage surrounding parts. The screws should pass smoothly (and without required screwing here). The whole purpose of these screw holders is to keep the nuts in place underneath, allowing easy assembly / disassembly of the OSWatch.

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Step 2: Fit Screw Holders

Next you want to make sure both screw holders hit nicely. You may need to do some extra trimming. You want them to be as flush as possible, and the screw holes should line up with the nut placement areas. (South screw hole not pictured, but do both at the same time)

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Step 3: Prep Nut Placement Areas

Now, using a soldering iron, X-Acto knife, and / or Dremmel tools, make sure the nut spot is clean, and fits the nut snugly. There should be a small indent in the center of the nut placement area, to allow the screw to pass in slightly. Be very careful here.

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These must be as level as possible. If they are not glued level, it will be very hard to assemble the rest of the shell.

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Step 4: Re-Validate Screw Holder Fit

Now place the screw holder back on top, and make sure it still fits flush. The nut needs to be completely recessed into the nut placement area. Make sure the screw holder holes are well aligned with the center of the nuts. This is your last chance to do any small placement adjustments.

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Step 5: Glue Nuts in place

Now remove the screw holder, and gently super glue the nuts in place, but ONLY ON THE OUTSIDE. Superglue getting inside the nut will generally make screwing it in impossible. I simply dabbed a little bit on the top of each of the six sides. and let a bit run down. This really does need to be glued in due to the risk of the nut stripping the plastic placement area on screwing / unscrewing. Also, you need to make sure the nuts are as level as possible.

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Be very restrained when gluing. If you glue the inside of the nut or screw in the screw before it is dry, it may fuze the screw to the nut.

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Step 6: Re-Validate Screw Holder Fit

Now, let the glue fully dry before the next step. (around 30 min or so, depending on how much glue you used.) Place the screw holder back on top of the nuts, and make sure it still sits flush. Some of the glue may prevent it from sitting flush. Use some sandpaper to smooth out the glue.

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Step 7: Screw in Screws

Now once you have confirmed it is flush again, hand screw in both screws into the nuts. Make sure both screws are vertical, and are aligned well. You may have to expand the screw holder screw holes at this point to insure both screws are straight.

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Step 8: Attach Screw Holders

Now it's time to glue the screw holders to the OSWatch bottom plate. I found it best to start off with glueing 2 - 3 small spots with a dot of glue and letting it dry a bit to insure alignment, and prevent it moving mid-glue. Then add a thin line of super glue on the outside of the screw holders connecting both to the bottom. Now, let this dry for around 20 - 30 min, depending on glue thickness.

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Step 9: Fit Logic Frame

Now, to complete the bottom assembly, we place the logic frame inside, as it will sit once the watch is complete. You will almost definitely need to sand the inside of the assembled bottom, as well as sanding the logic frame. You want them to fit together snugly, but not to the point where the frame is bending the plastic out to fit. You will also want to make sure the screws can pass clearly through the logic frame holes, and that they are vertical when placed in.

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You want to make sure the logic frame is flush with the edge of the assembled bottom. You may need to trim parts of the screw holders down a bit / sand the logic frame slightly. If you've done this correctly, the two together should look like the following image. If you cannot get it flush, this is where you can use the spacer.stl file for. It is not ideal, but you can add that later.

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About DoNothingBox

DoNothingBox LLC founded in 2013 by Jonathan Cook as a base to launch his passions, and showcase his portfolio. It's also to entity that holds any copyrights.

Updated May 16, 2014

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