I just received my Shapeoko Pro XXL and am doing final changes before starting to build the enclosure.
Question is, what size do I need the inside enclosure to be? As of right now I have it designed at from front to back it is 54" and side to side 48" with an inside height of 27".
Hi @ryanpfromthedb,
Welcome to the community.
I have determined the ideal inner dimensions for the enclosure of my Pro XXL to be
59" wide
51" deep
39" tall
(see A few weeks with the XXL Pro)
48" wide won’t cut it, the official footprint is 50" wide and you need some clearance on the side for maintenance access (e.g. oiling the rails)
54" deep is plenty enough. You don’t really need any space in the back, but it’s convenient to have some space up front
27" tall may sound like it’s enough initially, but picture yourself reaching into the enclosure for any reason: that’s a guaranteed head bump. Also, lighting. And dust collection hose/boom. And future upgrades. Really, make it as tall as you can afford, you’ll thank me later.
That said, YMMV, there are lots of threads about this and no two enclosures are the same depending on taste, habits, budget, etc…
@Julien
I updated the design I had my X and Y backwards with original design, so now the X is 59" and the Y is 52" with the inside height of 38". Would this overall design be good? would you recommend have sides flip down like the back does or does the 59" X axis give you plenty of space to do what I would need in the future?
It looks good to me!
I do have openings on the sides on mine and they came in handy a few times, so worth considering
@Julien
Here I did add some plexiglass so that at worst case if I can not reach what needs to be changed/fixed. I could unscrew the plexi from inside to take it out which would give me full access to the sides.
Consider adding a recess and some weather strip in between the plexiglass and the wood. It really helps cut the sound down. I used brass threaded inserts and large head stainless steel hurricane 1/4-20 bolts to secure the polycarbonate window on my So3 enclosure from the outside. An overlap on one door will help as well. You can use cap screws with washers as well. I bought a bunch of these bolts on clearance a few years ago so I had plenty on hand and I love the way they look but they are long and need trimming.
Also, plan ahead for where your dust collection hose will go (a common scheme is to have a shopvac hidden inside the bottom of the enclosure, and then you will need a hole for the hose to go through to the top compartment)
Looks like you have a solid plan now.
For reference, here is my enclosure design with Julien’s recommended dimensions, sporting a HDM placeholder.
One consideration is the height of your garage door opening. My cabinet is within .500" of the opening on casters.
The “floor” should be a torsion box (4 ft. x 5 ft.) and the whole cabinet should be built around it in a top section and a bottom section.
The top section should be completely removable.
On mine the floor and machine platform are semi-torsion boxes. I say semi because they don’t have bottoms.
@CrookedWoodTex
And why is that!? If the front and back open why would the entire top need to be removable?
@DiscoJon yes I have the same style floor but mine goes along the Y Axis as I feel it’d give more stability being the shorter piece.
I went along x axis since the vertical partition in the lower half was load bearing.
If you don’t have the bottom, you don’t have a torsion box. The strength and stability of the torsion box comes from the shearing strength of the two sets of glue joints separated by the height of the box.
@CrookedWoodTex
The top may not be completely removable but everything you stated other then a different sized machine has been accounted for. The back swing down for tiling, side plexi will be removable to work on the rails if need be
Hence why I termed it semi-torsion.
Hence, why I suggested it wasn’t “torsion” anything as is applied to a platform in case others reading that misinterpret your “semi”. 
