Thanks for the offer but I generally prefer to try new things myself because I won't get any better by using other people's stuff. But thanks anyway. I got close to making one once but I think I tried to over-complicate things by adding a corner which ruined it when I should have just left it simple and straightforward. I have Newton so I'll probably have a go sometime soon. Might start my own thread.
Just make an air time hill (slightly flatter than usual if you're building an invert, more pointy if sit down) with 3 nodes (A node that shapes the pull in and the steepness of the beginning of the roll, a node to shape the other half of the crest of the hill and to denote the steepness going down and then a node to level it out and make the pull out) split the middle segment of the element (the crest) rotate 180* lock handles and get the heart line the best you can, then split either side to get the 90* banked parts and improve the heart line (all these have cont. roll on) then split the pull in and pull out's until you have a node about 2/3m away from the node that's directly before the roll and than again for just after the last node (basically the first nodes either side of the roll at 0*) then delete the node just past/before that node so that the beginning of the transition takes longer to turn (I found this helped smooth it out) then highlight it all and cntrl+G and you should be good to go.
Here's a couple of my old sit-down rolls that I handbuilt before I quit:
And my Shmexy Cobra roll for good measure
The first one I completed but I don't think I uploaded the coaster and the second I gave up (was finding it hard to find some flow after the MCBR I had)
I will be returning to handbuilding rides soon, but since it's been 2years+ since I last made anything, safe to say I'm rusty and would rather play with Newton as it's so easy <3
EDIT: found some inverted o-g-rolls in my Photobucket
From 2008, so one of my first ever rides so not the best but :/