I built my large LR4 to process 48x96 sheet goods.
However, that does not allow room for the bit to cut OUT a 48” wide piece from larger material (e.g. MDF is 49x97) 
I am building a torsion box work bench that needs to be 48x72. At this point it looks like I’ll be able to do some hackery to make it work… but it’s gonna be super close.
Bummer that the footprint you have ended up a bit too small. I did that twice on my early LR4 builds, first because it was a new machine and there wasn’t a calculator yet, and then because I forgot to consider the size of the endmill when calculating the build size I was hoping to achieve.
In my own case, I was able to make the beam slightly larger and it was fine. I used “Lift plates” cut from 3/4" MDF for the Y rail and Y flat sides, so I just made those slightly larger and set them on the table with a slight overhang in the X direction. It worked fine in practice, though it still bothers me every time I think about it.
Can you post a picture of the lift plates?
I will when I get home from SMRRF
, or if I find an old post here.
They’re nothing more than 3/4” thick MDF cut to 3” wide strips that span the full length of the table sides.
Ah ok. Then new beans, belts and strut plates?
I did in fact cut new strut plates.
I was sad about that as I only made them 1cm wider, but that was all the more I needed to get fully around the cut sizes I was shooting for.
The only mildly interesting detail is that I used the first set of lift plates to match drill the additional ones. If I had been thinking more clearly I would have made a template for that.
I thought I’d eventually be surfacing a wood slab, and wanted the extra Z height- but haven’t actually surfaced a slab yet.
Luckily, the X and Y belts had been cut a bit long and they were still usable.
well, I pretty muchhave alway sized my CNC machines as an inch over what I thought I’d cut. My LR4 is 25x49 with a 24x48 spoilboard. with the jackpot, I defined the pulloffs as 12.7mm to give the 0,0 point as the corner of the spoilboard, but with the ability to trace the outside of the spoilboard.
That’s a good tip on defining the pulloffs that way - I’ll use that on my new build! Thank you for mentioning it!