oh, i wanted to put this little tip up for you. i'm sure others already do this but this is how i am rolling the pipes
first pic is the front side of the part and the 7 is the inside of the tube

next, on the backside you wet it with some water and let it sit till the paper soaks it in

next, take what ever size rod you want to use ( one that gets the edges to come as close as possible) and start to roll it.

it does take a lot of trial and error to find the right size to roll with. this one is about 2.11 mm in size. other one i used was about 1.48 mm..
next is to roll almost to the edge of the paper..keeping tight pressure as you roll.

next, i spread glue all along the edge

roll till you feel the "edge " of the paper under your fingers. you get the knack after a while feeling that you are right there, on the edge..

hold for a few seconds ...and then..

line to line..

one finished tube. not all of them came out as nice as this one. but the more i roll the better "most" of them come out
i hope this helps others with rolling tubes. like i said, the hardest part is finding the right size thingie to roll the paper with. after that, have fun