My drum uses 3" PVC schedule 40 pipe. 3/4" shaft, 3/4" FMC P3-U212H pillow blocks (Ebay prices are around $18).
What size motor are you using, and what RPM are you spinning the drum? I was thinking of a 5.75" diameter drum.. Is that too big? Or is it a matter of motor HP and pulley ratio? Is there a recommended Inch per second rate the sand paper should be moving across the material being sanded?
To keep the drum from walking or spinning on the shaft I put two opposing set screws in the 3/8" disks that I made to fit inside the pipe. Countersunk flat head screws hold the pipe to the three aluminum disks (one at the middle and one at each end).
So far, my plan is to epoxy MDF disks to each other and to the shaft..
The pillow blocks have set screws to lock the shaft. If you use wood or MDF disks you can use a shaft collar at each end of the drum or use a spacer washer at each end if the pillow blocks are close to the ends of the drum.
That's kinda what I was asking about.. Do pretty much all pillow blocks use set screws? It's hard to tell from pictures on amazon
http://ecx.images-amazon.com/images/...500_AA300_.jpg
Your 1" shaft can be stepped down to 3/4" or 5/8", but I would not want to go smaller than 3/4" myself. Yours will have more pressure on it if you use a conveyer and drum plus a wider drum. 1" pillow blocks with locks seem to be abundant. Google shows a lot of them if you search on "1" pillow blocks" Amazon.com shows them for just $9.65.
I found some decent looking ones on Amazon for $6.99.. Will I be able to find pulleys for the 1" shaft that are also compatible with pulleys for most motors... (haven't pulled any of the motors apart from the pumps yet, but I imagine they're probably 1/2' shafts (or maybe 3/4")
CarveOne