A Planet Mount and the wire that the planet mounts to

The planets mount to the shafts with a little thing that you can see in the first photo.  It is made in two parts and the wire that actually holds the planet ball fits into it.  This was a bit awkward due to a mistake I had made in my CAD modeling.

I had simply counted up the number of similarly shaped items.  I made one CAD model and duplicated it for the required number.  I realized later that each part was a different thickness so I moved some to another CAD file intended for a different thickness material.  I neglected to take the proper shaft hole size into account.  I decided to simply let that go, assemble them, and then drill the holes out at the end which worked after a fashion.  If I ever decide to make another orrery I can tweak the models a bit and have exactly the right parts come out.

The wire goes in like this

This is actually very tempting to do.  Now that the models are done and we know everything works, it’s very tempting to just bolt down another few pieces of plywood to the CNC router and cut out another set.  This could probably be done in one day.  There are a lot of parts – it could easily take several hours.  But there are CNC-based shops all over the country that would be happy to do this for me and send me the parts when they’re done.  I don’t know how much that would cost; it would be interesting to get a quote from them.  All they require is you send them the CAD models; they do the rest.  If we were to do it, I would invest in a special bit called a “compression” bit which cut down and up and the same time.  This has the effect of not leaving any splinters on the edges at all and no sanding would be required.


Then the cap goes on.

Here’s a tip kids: when you have access to a  CNC machine, let it do everything that requires precision.  You’ll be glad you did because you won’t have my situation where a normal twist bit rips out occasional splinters from the small pieces where the holes are close to the edges.  Also, the hole might not be vertical if you are too lazy to go out to your drill press.  *ahem*

In the end they fit OK.  But that’s something I’ll leave for the grand finale!