UITableView scroll smooth with certain speed?

Question

I'm building a custom slot machine with a column that exists of a uitableview.

When the user pulls a lever the tableview should scroll to a certain position with an index. I used the method:

- scrollToRowAtIndexPath:atScrollPosition:animated:

But this method will make the table scroll with a constant duration. So you will not really recognize a long or short spin.

I'm looking for a way to: A) Slow down the scroll animation. Or, B) Change the duration for the scroll animation to a self defined value.

The normal scroll animation (with the finger) does show this effect. Maybe it is a stupid idea, but is it an idea to invoke a touchesBegan and touchesDidEnd method on my tableView?

Thanks already