[eyerlander]

Im building a 120" x 12" x 12" cnc drilling setup for predominantly steel. i produce alot of linear parts and want a spindle setup that can run along a line as opposed to material movement. i have the majority of it worked out but am having difficulty finding the appropriate spindle/reducer to manage the speeds im looking at. the range im trying to achieve are 350rpm-3500rpm. most of the spindles im finding, the low is at 10000rpm. im not opposed to building in a reducer but dont know enough about how that would affect the torque. Ideally it would incorporate a vpn to dial in the speeds. I have reached out to several companies on alibaba but those that have low speed options seem to be low wattage, again, my knowledge in this is low, but i need something that can match 1.5-2hp for some of the drilling processes that im woring with. Straight drilling im using mostly cobalt, and for drill/tap i use a flowdrill setup.
Is this possible? any advice would be great. Also, this will be a system that will build as it develops, and the programming is taken care of.

[joeavaerage]

Hi,
I would recommend an AC servo. A servo can deliver constant torque from zero rpm to rated speed.

I bought a second hand 1.8kW Allen Bradley servo and drive for a low speed high torque (relative to my 24000 rpm spindle) spindle for milling steel.
Its rated at 6.2Nm continuous and 18Nm intermittent up to 3500rpm. You could therefore use this without a gearbox and cover your speed
range.

The advantage of a gearbox is that as the speed is reduced the torque goes up whereas my spindle (AC servo motor) does not and that may limit
the size of drill and the feed rate you can apply to it.

AC servos and drives are not cheap, even second hand. They are however very reliable and the highest 'power density' of any electrical motor,
thus for a given power, say 2kW, an AC servo will be smaller and lighter than ALL other motor designs.

Craig