My community minded friend with the CNC machine has been deeply involved with the robotics teams at two local high schools and has been totally unavailable for orrery work so my progress has been almost nil for two weeks.

This weekend I had the time to do a few things that are in the drawings.  I ripped apart the ill-fated pine board glue-up and re-glued the pieces – straight and flat this time.  When these dried, I went to the effort to smooth them (and remove the planer marks) with a hand plane and scraper rather than the usual sandpaper.  I am marginally skilled in these ancient methods and I’m not sure the final product doesn’t still need to be sanded.  But I’ll wait on that.  I do love the irony of using a CNC router to produce all my parts until the machine is unavailable and then I switch to hand tools.

Rather than wait on the CNC, I went ahead and cut the base on my bandsaw.  It is a very simple part and is easy to do.  I did pick up a spokeshave to remove the saw marks; thus bringing another hand tool to bear on the project.  I then drilled whatever holes were called for.

One of the gears actually uses the old peg-style construction; this is the easiest way to change the direction of motion by 90 degrees and so allows the crank to turn in the vertical plane (which is what humans do best rather than turning cranks in the horizontal plane) and the planet gears to rotate in the horizontal plane.  You sometimes see these in old windmills or waterwheel mills.  For this, I needed to cut a large number of pegs which was easily done.  Some time ago, I bought one of the Japanese style saws that cut on the pull stroke and became quite taken with it.  I’m not sure why it cuts so well although I suspect it’s just because it’s well sharpened straight out of the package.  Western style saws seem not to be all that well sharpened and I’ve read somewhere that in the old days, you were expected to sharpen yours when you got it according to what you were going to do with it.  I don’t know; all I know is that my Japanese saw cuts a lot faster and leaves a better cut than any other I’ve ever owned.  And it was cheap.  This made short work of all the pegs.

So I did what I could (although I took no photos).  I have everything I need now except for the rest of the planet gears.  I intend to also use the CNC to complete a base out of MDF and then another top out of pine.  I think the pine will look nicer and I’ll have the beginnings of my next orrery with the MDF parts.  I have a small amount of shellac in a jar which has clumps of junk at the bottom so I set out to filter it with a coffee filter but I made a huge mess and got it all over the place.  I guess the purchase of new shellac is in my future.

I thought of just cutting the other gears by hand but they all have little sections that get cut out of the center and I don’t have a saw that will allow me to take the blade loose and stick it into that space and cut the fine details.  I will just have to be patient.  And finally, the gear ratio necessary to move Saturn in the correct proportion is so high that one of the gears only has about six teeth – this is made in the style of a “lantern gear” which is built like a little cage rather than a disk with teeth.  Sort of a hamster wheel kind of thing.  This requires a disk of about half an inch in diameter that is drilled with 1/64 holes.  This is so small that I’m not sure how to cut it out – the plans don’t offer any hints.  My bandsaw is pretty big for that scale of work and the only blade I have is a half-inch blade with big teeth that I use for resawing; this is definitely not suited for small work. 

We’ll see.

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