I am sorry if this has been asked a thousand times, but I have spent several hours trying to navigate the site and really can't find an answer to my questions. I am thinking of building a new machine. I built my last one ten years ago when all this excellent lightweight modular extrusion didn't exist. There are several designs that I would be excited to try. The only issue is I can't seem to get a good understanding of the Z axis travel and clearance on the existing circulating plans. I need a work envelope of 18" x 24" x minimum Z clearance of 5" and travel of 10". On one regular job I work with a 6" long reach bull nose bit that extends roughly 5" from the bottom of the spindle collet. I need to clear a 3.5" lip of the work and reach down to cut through the bottom of the blank and 1/4" into the hold down fixture, which is itself 3/4" thick. So the gantry itself has to clear the 3.5" blank and the .75" hold down to be no less than 4.25" above a spoil board. Of course that is cutting things way too close, so really we need 5" of clearance for the gantry (or fixed bottom point on the z axis, whichever is lower). The Z axis has to retract the spindle so that the bottom of the 5" of exposed bit will be level with the lowest fixed point on the gantry. Of course I don't always use a 6" XL bit. The spindle has to also be able to travel down to the spoil board. The travel therefore has to be close to 10". I needed all that travel to retract the 5" bit, but if I have a more typical 2" LOC (or even a small bit with just 1/4" of LOC) the spindle has to be able to travel down almost to the spoil board itself. So, 5" up + 5" down means 10" of travel and 5" of clearance above the spoil board. Whew!!! Sorry if that is long winded, but I've had several arguments lately with people who insist, INSIST, that what I need is a ShapeOko with 3" travel and about 1.5" of actual workable Z. The OX seems like the best option because the spindle is mounted to an extrusion that theoretically can be any length. But I can't find what the existing plans give you for clearance and travel. Can anyone tell me off their actual built machine? What is the clearance from the lowest fixed point on the gantry to the spoilboard? The riser plates for the gantry look very low. With a spoil board mounted between the Y axis extrusions as called for in the plans, it doesn't look like the gantry would clear my workpiece and its fixture. I see that there are plans where these plates have been extended 50mm, but no where do I see what that has been extended to. If the clearance was 50mm to begin with and these "extended" plates give you 100mm, that still isn't even 4". With a lot of time and effort, I can probably design my own risers and Z, but I don't want to re-invent the wheel if it has already been done. Can anyone point to a design or build that would have the Z travel and clearance I am looking for? Thanks!