24" cross cuts or dados on a Radial arm saw.

You won't get the much cross cut out of the garden variety household radial arm saw. I think Dewalt made some long arm models that might come close, or check the Delta Turret arm saws. They might be able to come close (not sure). You can adjust the fence back (maybe) a little, but it won't gain you more than an inch or so. Dado across that much width might be better done with a router and straight edge. Your Craftsman RAS will "rip" cut to 24" (I think), so maybe you could rotate the motor and cut the wood that way. I don't care for the method because of the mess from the dust, but it works as long as you don't have a real aggressive blade (negative hook will work well on plywood in that setup).

Make half (or 16") of the cut, turn your wood around 180 degrees and make the rest of the cut from the other direction. It might take some fiddling to get the alignment right, but you should be able to crosscut /dado up to 32" that way.

My Sawsmith RAS, thanks to the sliding table, has a crosscut capacity of 21" - or 42" with the method above.

Larger capacity radial arm saws certainly exist but you might
consider building a crosscut sled for a table saw or even a
jig for a handheld circular saw if you just want to get the
woodworking done without chasing down an old machine
and dealing with whatever issues it may have.

If you want a larger radial arm saw it may take awhile to find
one and even then you may have to deal with a 3 phase motor.

I believe some of the larger 16" RAS made by Delta and Dewalt will have that capacity, they will more likely be 3 phase and in my opinion not all that necessary for cabinet building. We cross cut our full sheets on our table saws with a 52" Tsquare fence. I have sufficient side and out feed tables that surround our table saw and so none of the weight of the sheet is in our hands, we are just guiding the sheets through. We also run our dado on a table saw with no problems at all with sufficient side and outfeed tables.

We do have a 12" Dewalt RAS, but it does not get used that much.

If you can't x-cut 24", you can turn the cutting head 90° and do a rip or dado cut.

you should look at some of the counter top guys in your area I have seen large radial arms in that environment as they use them to cut the 45 degree angles on the ends of the tops. good luck in your hunt. Paul

Much easier to cut on a table saw, or with a router. With a simple jig it's a breeze with a router, and not as dangerous as a RAS.
Ed

I agree w/ Carver, much easier to do w/ a router.

new blade in your skill saw and clamp a cross board (they make a metal clamp combo just for this). Also go for router and dados.

I have a table saw now but many years ago I did a kitchen without one.

I worked in a Millwork shop and we had a 14" Delta/Rockwell RAS that only had I think 22" of travel. We also had an 18" DeWalt that was used for dirtier tasks, it had around a 26" - 28" travel. That would work for what you're trying to do, but would be a real PITA if not being used all the time. Very heavy, took up a lot of room, three phase, expensive blades, very expensive dado set. I'm sure there are many better options for a home shop.

There was a guy on Youtube who built a "radial arm saw". I think
the arm didn't actually move and he mounted a circular saw
in there… it was only to make dead-square cabinet crosscuts.
It was all made of melamine put together with screws and he
waxed the melamine where parts needed to slide. It looked
like it worked well. Great dust collection too.

Another idea. Crosscuts 27"

Loren, Great idea. I wonder if drawer slides would work in place of the table saw.

Well, I think they would have more play in them. You can get
miter gauge inserts for router tables. That way shop-made
miter bars could be used or even the fancy metal ones that
are adjustable to tune out slop.

You could also use v-groove bearings riding on pieces of angle
iron. This is not unlike the sled built into Millbury tenoning
machines. My shop built 3 axis panel saw has the top carriage
mounted on 4 inch v-groove gate wheels riding on a piece
of angle iron mounted on an aluminum beam.

Thanks all for your thoughts. I really appreciate the input. I plan on making the wall units first so I'll use the RAS to dado those. I'll practice on some scrap to see if I have the accuracy to flip the wider bases around and make one dado in two passes. I may even try to turn the blade 90 and rip a dado. In the mean time I'll be reading up on dadoing with a router and making a sled for my table saw.