I've taken to developing 4x5 film in a Unicolor drum. I don't have a roller base. Instead, I took four furniture wheels and a piece of wood. I drilled four holes in the wood and put the rods from the wheels (which would normally go into the legs of the chair) into them. I put the drum on the wheels and rotate it with my finger on side of the flat protrusion from the rim.
I found that I was scratching my negatives as I slide them in. To avoid that, I bend the negatives in the opposite direction from the wall of the drum, move them into place, and then push on the middle of the negative. They snap into position.
I am careful not to tip the drum onto its side once the negatives are loaded, but I have to tip it to dump out the developer. Since I don't have separators, there is some danger of them moving and overlapping each other, keeping the fixer from working. But once the developer is out, I figure I can open the drum and reposition the negatives, especially if I do it under my darkroom's safelight. Is that reasonable?
Any other thoughts?