I needed an HTD5 pulley for a project, this was a bit odd as it needed to be fixed to a spinning bearing housing rather than to a shaft so I decided to make one on the machine. I used the cambam trochoidal plugin for the roughing allowing the entire part to be milled with a 3mm endmill, took a bit longer but meant no tool change. Part was cut dry with air to clear chips, worked out really well.

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Trochoidal clearing is excellent, no gummy chips sticking to the endmill. This was cut from some 5000 series (not sure exact spec) scrap plate, it is quite gummy, would have been better in 6061 but I didn't have any to hand. Still the part is more than serviceable for its intended purpose which is to drive a multi-turn encoder (near zero load). Was cut at 3mm DOC, 15% stepover, 24k rpm, 3000mm/s for clearing (although the machine never gets anywhere near this on this part due to the tiny radius of the spirals).



I will probably recut it with a high speed profile to finish, the finish pass was way too slow (600mm/s) which led to rubbing and the surface finish not being perfect. This was entirely my fault for rushing the CAM and not setting the feed.