Smoking a 7-10lb Chuck Roast?

What I'd like to do is get a chuck roll and cut it in sections then smoke 'em one at a time when I want to make pulled beef sandwiches. The problem I had with the last one (whole chuck roll) is it didn't get done so I had to put it in the electric roaster. Of course it came out tough. I was not happy with the results but everyone else seemed to like it. I'd like for it to come out tender and moist (and easy to pull). What I need is a smoking schedule so to speak. I use a pellet smoker and can regulate the temps easily. Any help is appreciated. Thanks.

Thanks Guys! I guess I need to cut 'em up. I tried smoking a 21 pounder for 19 hours. I threw it in an electric roaster and took it to work. When I started cutting into it I was shocked to find pink inside. I threw it back in the roaster and cranked it up to 400. It got done but was real tough. I may pick up another chuck roll in a couple of weeks and try it again.