Step 8: Put It Together for a Real Test
Start by mounting the servo drive gears and the lens gears. This is all pretty straightforward, but if you find that your lens gear is slipping at all (as mine did), it may help to know that you can increase the grip of anything with the rubber backing that's easily peeled off the back of a cheap, thin mousepad. The same stuff can also be used to deaden noise from the servos. Along those lines, adding some plastic-safe grease to the servo gearbox can also help reduce the servo noise. I used fishing reel grease that is designated as plastic safe, and it really quieted my zoom servo.
If you don't have a rail system, you'll need to fashion one by either following what I did (I'll let the picture guide you) or find an even better design on the web. My rig was put together quickly for testing purposes, and I plan to replace the cobbled-together design with something more attractive, rigid, and easy to adjust. My rails are 1/2 diameter carbon ski poles that I snagged from Goodwill for $4 (Goode brand are not tapered, so they worked well for this). The rail holder is made from a 1/2" thick hard plastic cutting board that I sawed into a 2-1/2 inch wide by 6" long strip. To create the rail "holes" I routed two 1/4" deep by 1/2" diameter grooves with a core box bit mounted in a router table and guided by a small fence. I now wish I had made thiis whole thing wider, but I wanted to keep it narrow so I could still get to my battery door without dismounting the camera from the rails. I then cut the piece in 2 lengthwise, mounted a spacer block of baltic birch plywood to one end with some wood screws, and then drilled a couple of 1.4" holes in it for attaching it to the camera and the Manfrotto quick release plate.
Once you have a a rail rig, you can fashion some servo mounting blocks to fit your rails. I also made mine from some hard plastic cutting board scrap that I routed on my router table. I screwed one end together with some small drywall screws, and drilled a 1.4" whole on the other side of the rail hole to hold a carriage bolt. A small knob allows me to tighten the mouting block for a pretty snug fit on the rails. Once I was sure everything fit OK, I drilled tiny pilot holes to fit the servo mounting screws that came with my servos, and fastened the servos in place. Note that with this arrangement the servo is only fastened at the front edge, so be careful where you exert pressure when mounting the servo and block assembly on the rails.