I am on a mission to create a tool for work. What I need is around a 15:1 reduction, a 90 degree transition in drive angle and the driven shaft will move up to half an inch along the driving shaft. This drive mechanism will be driven by a cordless drill. I am thinking I will need to make a worm gear set with an extra-long worm to allow the worm gear to move along the worm axis. The worm has to be less than .375" OD and the worm gear less than 1" OD. The other option is a helical gear set.
My questions are 1) Have any of you seen this type of drivetrain? 2) Do you think this is possible without being prone to failure? 3) Do you know of a supplier that sells worm or helical gears in "stock" form so I can cut to my needed dimensions?