Am I expecting too much from the X-Carve I have on order right now?
Eventually, once I learn to use it and get the kinks worked out I’d like to be able to mill plywood sized 36 x 24 x 2.5 inches, into a complex topographic contour map.
Once I get that mastered, I’d like to do the same with a solid piece of (expensive) aluminum.
Creating a contour map that large from plywood is within the capabilities of the X-Carve, but be prepared for a lot of failure and disappointment till you have the machine tuned and solid. A detailed 3D carving that large is going to take many many hours to complete, and from my experience when doing really long duration carves on the X-Carve there is plenty of time for anything that can go wrong to do so with a vengeance. This is especially frustrating when you are 8 hours into a project.
I would start with much smaller maps, maybe even just making lots of 6x6 inch sections and then gluing them together so if something goes bad everything’s not lost.
As for doing the same carving in aluminum, I have not done much metal work with the X-Carve but in my opinion I think it would be very difficult if only for the extended amount of time it would take.
Also, the 1000mmx1000mm X-Carve has a 31" max working area, so you’d have to tile the material in order to get 36"
You’d have to extend the Y axis to fit a full 36" piece in there. Otherwise, what @AllenMassey said.
The XC is a great machine to learn on and it will handle the plywood just fine.
I recommend getting a down cut bit and doing one of the stiffing mods.
36" (914mm) is going to bigger than the XC carving area (900mm) but as long as you don’t want to carve to the very edge of your stock it should work fine.
As stated, start small until you get things dialed in. Especially with aluminum.
while I wait for my xcarve to arrive I am expecting something similar. Plywood and aluminium. Are these “stiffening mods” suggested because with the 611 the rail bends and the cuts aren’t parallel to the wasteboard? Or because rigidity is needed to increase cutting speed?
A little of both.
The XC was originally made to hold a small spindle, about the size of a Dremel.
The larger and heaver routers cause the gantry rails to twist forward a bit from the weight.
The stiffing mod tightens this up. They will all work. (As to which is best? who knows without some serious testing.)
Also if you look closely on a un-moded XC you may actual see the bit shift as cuts forward and back along the Y axis as the gantry flexes (I did with mine). Cutting slower will help with this some. But with the mode it ceases to be a problem.
You will want to add some brackets to the Y axis as well for similar reasons. The faster you cut the more shake and wiggle you get. you can always just cut slower, but on larger jobs that can get very timely.
Also when calculating your feeds RPM will have a big impact. For example GWizard will want to run at MAX RPM for some cuts, but doing so will run the XC at feeds that will have poor finish quality. So throttling back you RPMs in the calculator may help yield useful numbers.