I could use some recommendations for small, quiet servos, as well as a question about mounting them.
Is it okay to mount one servo directly on top of the horns of another? If so, can I use the same size servos or should the top one be smaller, and by how much? Should I reinforce the horn with a small piece of metal to provide added stiffness, or is the plastic usually sturdy enough to support the weight?
At the moment, I am looking at the following two servos in consideration:
Has anyone ever worked with HobbyPartz.com or those particular servos? Do you have other recommendations you'd make? This is my first project of this type, so I don't have loyalties to any past company or brand. I'm looking for very tiny servos (less than 2.5cm/1" for the top one, and less than 4cm/1.5" for the bottom one if it needs to be bigger), and preferably fairly cheap as well (less than $10 per servo is good, less than $5 per servo is great - I need four, and another part of the project is a real moneysink, so I'm trying to save where I can). I know most every servo makes noise of a sort, but some are louder or higher than others (I've heard digitals can whine, and high squeals bother me more than low hums - the "mosquito tone" is a valid weapon here).
Torque and speed are low on my priority list. The absolute most I would ever need the servo to manage is 100° in 1/4 second, and that is a very extreme case - most turns will likely be 10° or less in the same amount of time, and I'm sure almost any servo could manage it. The whole weight on the bottom servo will likely be about 15g/0.5oz (dependent on the weight of the top servo), while the top servo only has 10g/0.3oz, so the load being moved is quite small. My primary concerns are size, noise, and cost - smaller and lower all around. What are your favorites to work with, and what would you recommend to me?