[NogginBoink]

Long time lurker, first time poster.

I've gotten my hands on a CAD package and am in the process of designing a CNC router. I'm curious to know what others' routers Z-axis travel distance is. I've started off using 6 inches as a target, and now that the drawings are coming together, it looks like I might have some large moment arms and reducing that distance might give me some additional stability.

I imagine I'll only be cutting sheet wood (and perhaps sheet aluminum) materials... at the moment I can't think of any material I'd want to cut that's thicker than 3/4". Of course, it never hurts to give myself room to grow in the future.

Anyway, I'm curious to know what the limits of Z-axis travel are for other routers out there.

[CarveOne]

I wouldn't recommend less than three inches of Z clearance to the table top unless you know for sure it will only be used for 3/4" and thinner materials. You need room to have a removable dust shoe and clearance to change tools. Z axis travel needs to be able to have the router/spindle reach the table with a short cutter, and to retract the long cutters to at least just above the lowest fixed point of the Z assembly. Being able to raise it any higher is just making it easier to change cutters. You can't cut anything if the cutter is above the Z assembly clearance. My smaller machine has 2-1/2" clearance to the spoil board and I need about 1/2" more clearance for some projects. My big machine has 6" clearance and 8" travel. It was intended to cut 5" thick material for molds.

[Falcon69]

I will be redesigning mine to possible 18 inches or 24 inches. The reason, I want to add the ability to use a 3d Printer. But, in order to mill aluminum on my machine, I'll need to rethink the design of the uprights and the z-axis carriage. That may prove more difficult than it is worth. At the moment, my design sits at 6inch of full travel for my Z. Meaning, the bottom of my gantry sits at about 6.5 inches off the top of my spoil board. That leaves 1/2" for cutter length.

If you plan on doing wood carvings and such, like taking a 6inch thick piece of solid oak and milling it into a nice carved bowl or something, you'll want your gantry height tall enough for clearence, and you'll need to think about the travel of the z-axis, as well as the strength of the gantry uprights and the z carriage. You'll also need to think of things like distance between the profile bearings on the z-axis and on the gantry uprights. The higher the height on the gantry, the further apart you'll want to make the bearings. More distance travel on the z carriage, the further apart the bearings.