In order for the parts to solder well, I need to flatten all the mating surfaces – the top surface of the bottom plate, the bottom surface of the top plate, and the bottom of the gears (there’s a parsing conundrum for you!).
I use a file most often for this
, but a flat plate topped with sandpaper would also work. On the bottom surface of the top plate (the lowest piece in the image above) I’ve used a black Sharpie™ permanent marker as layout fluid so I can easily see the low spots and know when I’ve accomplished flatness.
Next I need to cut the pockets the gears will fit in to do a “disappearing act” into the top plate of the trilobite. Above, I’ve colored the silver with a red Sharpie™, carefully positioned the gears and then scribed a line around them so indicate how far into the plate I must remove the metal.
I also need to mark the depth on the inside of the gear pocket. Once again, I press my Sharpie™ into service, and scribe the depth with a pair of dividers (see above) – after carefully measuring, of course.
Above is a view through the engraving microscope. I’ve been using small carbide burs to carve away the metal that needs to be removed.
Once I’m close on the fit, I use a flat graver to remove the inside radius left along the back corner, and then use a small scraper to refine the surfaces. This scraper is the one I used in much of the carving of the Orca Knife – it carves metal really well. Heres the link: http://sterlingsculptures.com/wp/?p=2333
And, at last, the gears fit, the surfaces are flat and ready for soldering. One last gear left to make, which will go on top of the large gear in the circular opening, and then we can get on to the fun parts.
Thanks for looking!