I’m not too fussed about having a glossy finish - just as long as it doesn’t leave a grainy texture, even a smooth matte texture would do fine.
Not grainy at all after machining. Definitely a grainy feel to raw stock.
Starboard is SLIGHTLY preferable to HDPE… but they machine at the same rates.
One thing to keep in mind is that the STL file one feeds to MeshCAM should have the highest number of triangles you can get your CAD to emit. The more data, the better the surface fit, especially for round features.
It’s also important to turn the MeshCAM tolerance to 0.0001" (or the metric equivalent) and let MeshCAM wail on the data. The more time spent in MeshCAM, the less machining time and the best finish.
Next comes the size of your end mills and the type. I recommend AlTiN coated end mills for everything other than Al and Al alloy. Small end mills can be easy to break so learning to use them properly - to get the finest features - is important.
I would rough with 0.125" and work your way down to 0.0625" or even 3/64".
I would seriously consider Onsrud specialty plastic cutting end mills. They look expensive… but they aren’t! They are works of art and last for a long time.
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