Laser Level "Extra Slow" rotation mode

I have a MasterCraft rotating laser level. This thing is incredibly handy for laying out partitions or T-bar ceilings but the one thing that always bugged me is that the rotation speed is to fast, even in the slowest setting. I brought it into the shop today and added a 2 position switch onto the DC feed to the rotation motor. One side is a straight connection, the other side directs the current through a pot, all I had in the shop was a 1k , 10-turn but a 10 - 20ohm, 2 turn would have been perfect.
Cheers
Rob