Is 3nm motors to strong or is it ok to go upp in power for 10Amp 230v

Since the Z-axis (like X and Y) is direct-driven without a force reducing gearbox, I realize this spindle's weight may cause the Z axis to drop when the cnc is powered off.

I don't know what kind of brake system you use on the larger machines you build, but I am going to design an electronic brake that locks Z axis when the machine is powered off. This will keep the stepper locked, no matter if the machine is powered off manually or if power is lost due to power outage. This will protect tools and material.

I am considering tapping into the e-stop feature, so that the braking function works seamlessly with the other  workings of the machine.

Any thoughts or considerations you think I better know before I start?

So, to me air cooled seems to be a safer choice. I have a Makita router of the same type that is used in the build video. But I was thinking about putting a more substantial router on it. I have been looking at VFD-controlled aircooled routers. And I notice that for example Vevor (the chinese trader that has warehouses around the globe, including in the EU) offers several options. From 2.2-4 kW for example. Often they are mounted in a rectangular aluminium holder with brackets for mounting to the machine plate.

I know you spoke in a video about routers, but there's a lot of videos by now. So I wanted to open a discussion here. How should I think about things like:

* Power - what kW effects are appropriate for different usage application (mdf, hardwood, aluminium - and would it even be possible to cut harder metals with the right spindle and using very low feed rates?)

* VFD - using a VFD reduces noise and increases lifespan of router as far as I've previously learned. But it also introduces risk of electronic interference (EMD) as well with the machine itself as with the grid. What should one think about? And is there room in the kit box to fit a VFD for those who want to go down that route?

* Weight - how much motor weight can the machine handle (kit steppers in mind) before it becomes necessary considering adding a brake mechanism so the spindle does not drop when at rest?

* Does the choice of a "bigger" spindle as to its electrical power consumption change the needs regarding cable dimensioning? And does that affect the choice of cable chains?

As I am originally an electronics engineer, I want to add a small thought on the electric discussion for our american friends. In Europe we use a 230V grid at 50Hz. Since the electrical power law constitutes that power P=U*I where P is power, U is voltage and I is current, there is one important thing to remember.

Since the american grid voltage is about half of the European, to deliver the same amount of electrical power to the router you will need to have twice the amperage. That means that the cables used must have more copper. In machines I've been part of building, where we used 1,5mm2 wires, for the US versions we used 2,5mm2. 

I am currently working on the video that will cover the electronics, control box and software setup. This is an important part of the machine, so I want to make it as clear and useful as possible instead of rushing it.

In the meantime, members on this site already have access to simpler drawings for an electrical control box. That control box is very similar to the one we are going to build in the video, and it uses the same main components.

So if you want to start planning the electronics, you can already look at those drawings and get a good understanding of how the box will be arranged.

More detailed videos, illustrations and setup information are on the way.