I noticed upon checking my design by matching up the 3D models in sketchup that the real movement created by the gears is relatively minor.
In terms of the drawing mechanism I mean.
The machine is much smaller than the Cycloid or othe wooden drawing machines - at least at this basic level and without glueing gears together.
As a result tolerances quickly add up
After all the actual drawing area is just abut 15cm, usable about 14 in diameter.
The teeth are not a big issue here once properly worn in as they have a 25° pressure angle.
But free play in bushings and mounts for the slider holding the drawing bar would create rather nasty jumps and jerking depending on how extreme you mount and combine things.
So I once more create new t-mounts and will add another spacer to allow the gear to mounted spinning but basically free of play in the x and y direction.
Take some more sanding but well worth it I think.
Next issue I encountered in the 3D model is height.
The drawing arm must be mounted above the nut and bolt holding the gear.
Being printed means I can't use flat nuts and fine pitched threads or a clamping mechanism.
So the mounts for the arm need to be solid from the nut up and also have a similar bushing as the gear itself.
A slotted drawing bar as used by the Cycloid works great in wood but no in plastic, especially not if you need to keep things sturdy AND moveable with little play.
With little control over how other slicer will create an infill pattern I need to desing a light weight bar from several parts that combines allow for as little flex as possible - while keeping the material costs low.
Every time you get close to the finish line you see another deep vally and long climb ahead of you LOL
Don't even want to think about the nighmares when trying to add stacked gears.....
