Print base plate and end plate for just 2 pieces of pie
If your greedy print the link plates and expand to suit the number of slices of pie required.
The thing's slot together before sliding the case in. Hopefully locking them together.
No support, 2 wall's, 30% infill, 0.3 layer, nozzle is 0.46 on my printer, I also found that slowing print down prevented curling of the key ways (failing that a touch of filing n super glue might work)
BTW the pictures are of straight of the printer (no touch up)