Well, my attempt to make the world's smallest p/t worked, after a fashion. That's to say, it worked on the bench. ;D. Didn't take me long to realise that it was just too delicate for fitting to the E-Revo.
The main reason I wanted to make it small was that it needed to be low-profile because I wanted to place the camera as close as possible to the driver's head position - As close as possible to the right-hand side window and mid-way between the wheels. If I was also going to be able to angle the camera up to look through the roof ( more of that some time later ), the p/t needed to be low. I decided I also wanted it to be reasonably fast and I wanted some decent bearings on the pan servo because there would be a fair bit of weight in the pan assembly. I ended up with a Savox SC1251MG. It's about as low as a standed-size servo goes, has good bearings and metal gears. I don't expect (EVER!) to have any problem with this. It's built for 1/10th scale steering so this application won't exactly tax it.
I'm sure I could have chosen a cheaper and lighter tilt servo but, once again, I wanted something robust, with decent bearings and, ideally metal gears. The Turnigy TGY-S712G fits the bill nicely and, because it's slim, it fits nicely on the back-plate of the HobbyCity P/T ( Large )
The P/T is cheap, well designed and light. It's a little flimsy, so I reinforced the base plate with a piece of 2mm carbon fibre. The circular servo horn goes through both plates and the whole lot is held together with Shoe Goo which, once it's set, has just enough "give" but holds things securely. What's more, you can peel the whole lot off if you want and start again. It's great for test-fitting CF components!
The tilt servo linkage for the HK P/T is a little flimsy so I replaced it with some M2 hardware that, I believe, comes from a Kyosho helicopter.
Anyway. here she is...
Height ( aimed up ) 91mm
Height ( aimed straight ) 70mm
Footprint ( diameter ) 76mm
I'd be interested to hear if you have any suggestions / comments. Also, any suggestions how I can get 180 degrees or more rotation from the pan servo would be very welcome.