In my experience, having gcode controlled spindle rpm has proven very useful and allows you to achieve consistent chip load from one job to the next. Combined with the bitsetter(which I don’t have yet) it would make for a really seamless job.
It also means you need to remember less… If your tools are configured correctly in the cam software then you never need to set spindle speed, at all.
How about a speed controller with feeback loop from tachometer for the router? The power would be adjusted to maintain proper RPM or feed speed adjusted if the router cannot maintain set RPM.
This is what SuperPID does, you install an optical sensor that can see if the router is beginning to bog and increase power. I’m sure there are others that work this way as well, I’m only familiar with the SuperPID.
Dan
I think, getting back to the original question, a Makita is the best bet. Even a converted brushless cuts aluminum quite nicely.
All sorts of trade offs, side benefits, personal preferences that only experience will mold.
Go with a Makita. Move on from there if you like.
That’s what the stock Makita, Dewalt, and CC (reportedly) routers already do (even without “Super PID”). That’s one of the main disadvantages of routers - they’ll provide as much torque (exert as much force) as they can to try to maintain speed. HF Spindle VFDs limit torque (hence machine forces) to whatever level they’re set to. Higher speed = less machine force = good, unless the spindle, tools, workholding, machine operator, or machine resonanances can’t handle it.
Is that important? Why?
It means that my speeds and feeds are the same from one job to the next, once I’ve got a good combo for a material I want to stick with that… Having it already dialled in the software is time saving and more accurate…
Do your speeds vary much from one job to the next? If so, is that to maintain optimal chiploads that you’ve established for the jobs?
They sure do, for example I may do a job in timber that uses a 1" surfacing but, a 1/4“ flat endmill, and a 0.5mm tapered ball nose. Each of these tools requires a different rpm and feed rate. Then if my next job is aluminium and I’m using A single flute 1/4" bit, and a 1" surfacing bit, the feeds and rpms are different again.
being able to change spindle rpm through gcode is definitely a useful feature for me.
I think I’m missing something here. Are you saying that maintaining a constant spindle speed is = bad? I don’t see where NOT holding constant speed (bogging down) = good? It’s late, been a long day in the shop, I must be reading that wrong, if so please disregard.
Dan
Attempting to maintain a constant spindle speed is bad (and potentially dangerous) if a spindle increases torque (hence machine forces) up to 10 times its maximum rated operating level trying to do so. This can happen when routers can’t maintain speed because something (mishap, hitting a knot in wood, etc.) prevents it.
VFDs for HF spindles limit the torque/force to user programmed levels. They can also show spindle RPM and are typically quiet enough that the operator should hear when they start bogging down so he/she can reduce feed rates as required.
Haven’t run the 60k for a minute because its 220v. The 24k 1.5kw has been running the show because it rides in the back of my truck from Houston to Austin every week.
Aluminum work - Makita rocks with 30k, needs single fluted to run hard. Easy and 3/8s compatible
That sounds brutal - Haven’t been to Houston but really enjoyed Austin whenever I visited there!
That quiet “passively cooled” ATC HF spindle looks/sounds pretty good and it’s reportedly manufactured in the USA! Here’s what it can (and could potentially) do with steel!
Yeah, I’m been watching them for a while. It’s an impressive spindle especially for the price and USA made. It’s frame size and weight (~26lbs) might be a little much for the poor little Shapeoko though 
Highly recommend the 1.5/2.2kw spindles, they can chew through aluminium fairly well
Which spindle at what speed with what grade of aluminum? Your cutting power was probably about 50 Watts.
1.5kw air cooled, 6082 T6
An interesting development here is the Carbide Compact Router w/ ER-11 collet:
which affords one an easy transition to a spindle, and access to various collet sizes.
and note that I finally mounted my Mafell FM 1000 WS in such a way as to put the tool at the same center point as the other options (so no lever reduction advantage):
and that I’m still fiddling with dust collection options (either an adapter plate at the bottom, or a hacked up Sweepy Pro which needs further shrouding at the top to get the dust collection to work at the bottom.