With the way wood can move as the result of humidity changes, I would like to add the suggestion that a large BLA (Backlash allowance) is best to get smooth operation. I made a a planetary set, and had to sand the tooth surfaces to make it run smoothly.
The planet carrier is not necessary, but I added it anyway.
Use the same system to draw the internal gear, but add the BLA to the circle radii when you draw the tooth surface, rather than subtracting it.
Good judgement comes from experience.
Experience comes from bad judgement.