Onsrud Einschneiderfräser, 1/4" Schnittdurchmesser, für Kunststoffe, Holz, Aluminium und Mineralwerkstoffe

CNC router build -- hortizonal setting for router, to taper bamboo rod blanks -- how do i do?

If you want to taper the surface of wood blanks, it would be best to create a fixture for clamping the blank onto the table where one end of the blank is raised and then you use a surfacing bit to flatten the top side. Additional Information: A tool like this would work well to surface the material: https://www.buildyourcnc.com/item/endmill-surfacing-cutter-onsrud-2-insert

Can you suggest a end mill that would cut 5/16th epoxy terrazzo sheets?

We are hesitant to recommend a specific end mill because we do not have direct experience with terrazzo sheets and this material has a unique combination of properties that makes it difficult to estimate which characteristics would be most important for the end mill. However, we have had good experiences with C.R. Onsrud endmills in a variety of applications. Their catalog can be found here: http://www.onsrud.com/files/pdf/2014-Onsrud-Complete-Catalog.pdf We would suggest looking over their specialty materials section for materials that most closely match what you want to cut.

How small of end mills are commonly used for cutting balsa? What thickness of balsa can these smaller mills handle?

The size of end mills can vary to extremely tiny to very large cutting diameters. The smaller the cutting diameters, the shorter the available cutting length due to the possibility of breakage. You will first need to determine the thickness, or depth you will need to cut and find the available cut diameters for that depth. To cut balsa wood, almost any standard 1 to 4 flute end mill will be fine that are intended to be used with wood. The end mill will state the materials that it can cut. Wood end mills will exhibit a flute geometry that is more stretched out to straight.