While I am certainly no expert on speeds and feeds I did spend a number of years calculating them for machining metals. In my experience these calculations are a simple starting point. I tend to rely more on the sound of the machine and the finish on the material.
I try to keep my chip load between .002 and .004 depending on the material. I also limit my depth of cut to half the diameter of the cutter to be on the safe side with a plunge rate of about 30% of my feed rate. These are not commercial production machines so you can’t run them at the bit manufacturers feed rate but you can certainly run faster than the very conservative feed rates calculated using easel or carbide create.
So I use the simple chip load formula noted above, chip load = feed rate / (rpm x # of flutes). My spindle sipped is 17,000 so the denominator is 34,000.
For a 1/4 inch two flute cutter I run at 100 inches per minute in Baltic birch which gives a chip load of 0.0029. I run the same cutter at 85 inches per minute in white ash which gives a chip load of 0.0025. At these feed rates the machine sounds good and I am happy with the finish. The math says I can go faster but as I said earlier these are not production machines and I don’t do production runs.
For a 1/2 inch ball nose I run at 75 IPM with a 10% step over for white ash and 85 IPM in bamboo.
The reality is there is no magic number for speeds and feeds. You have to run your machine at feed rates that YOU are comfortable with.
If you are looking for a good source for chip load charts Amana tools publishes this data for every tool they make but please keep in mind these feeds are for commercial machines. For example they suggest running a 1/4 two flute bit at 180 IPM with a 0.005 chip load and a plunge rate of 90 IPM with the depth of cut at .250. In my opinion you would be crazy to run the LongMill at these rates.
Hope this helps.
Jeff