Your comment: "Who feeds the mill 25 IPM at 3500 RPM?" What does that mean?
Your comment: "Most users do the full speed, around 25k RPM. That would require a feed of
178 IPM for best result." What does 'most users' mean? People who do miniature carving, such as jewelers, use super fast spindles (100k) with very small stepover/stepdown (bite) values. An industrial millworker friend of mine has some very large mills that run around 3k rpm and when using large endmills (1", 2"), the feed rates aren't very fast either. Conversely, I observe on youtube all kinds of people using machines at different feed rates and bite rates, some very fast and aggressive.
Your comment: "Seriously, these high speed spindle motors are pure BS except for engraving." I have a product in patent pending that I used the micRo for creating test prototypes with parts almost 1" thick. That is cutting, not grinding nor engraving. So, if used right, the micRo can do more than just engraving.
I once contacted MSC, who provides customer service, and asked them the recommended feed rate for a particular end mill that I wanted to buy, expressing that I have frequent tool breakage. I gave them all the parameters and they calculated a 78 ipm. Their math was correct, matematically, but on the micRo anything over 20 ipm on alumimun frequently breaks the tool, especially during initial plunges at each new milling level where 100% of the endmill engages, even if it is for just a short run until stepover is possible. Conclusion from this: we need to adapt/adjust the theories to the micRo's capabilities.
By beefing up the spindle, I am trying to see if I can improve on time, by using a bigger end mill, say up to 1/4". Currently I am able to mill aluminum and brass, but it takes forever. Is anyone interested in seeing if a stong router works on the micRo? I am, because if it doesn't work, I will just have to save up big $$ and get a different system. But first, I will try.
It seems to me that most peole on this forum are interested in working on the electronics of micRo and/or creating pcb boards, that I assume only use 2d milling.
So, is there anyone in this forum that actually uses the micRo for 'traditional' milling or other applications where we can exchange experience with the actual use of the micRo that would be mutually beneficial?