Royal Servo
 

Hi all. I bought a used plane and it came with some "Royal" Servos. I have no idea what these servos are. They have black casing with no model number on them except for the brand name (I think) "Royal" and some maple leaf shape pattern. I really have no clue what these are as some of the gears need to be replaced. Can someone please help me? Thank you.

RE: Royal Servo
 

Back in the 50's and 60's these were quite prominent. I assume these are the three wire ones (they also made 4 wire servos then). If so, they are most probably set up so that 1.2milliseconds is the neautral pulse width and have a 4 sided spline. They will work with modern equipment but; at neautral input, the output wheel will not be at right angles to the servo axis. You can correct this by opening the servos, loosen the screw that hold the potentiometer in place, and rotating the pot untill the output wheel is at right angles to the servo case when inputing a 1.5 millisecond input pulse (the neautral pulse on most modern transmitters). Then just tighten down the screw holding the pot in place and reassemble. These old servos may have some problems with dirty potentiometers though, so, if you can, use newer servos on the main channels. Reserve these for throttle or flaps.

RE: Royal Servo
 

They may be Royal Products servos that were being sold mid 80's thru mid 90's. Could the maple leaf actually be a lion? Royal used a Leo Lion as their "symbol". These are OK servos, about 40oz output, have a splined output shaft and should work fine with the newer radio gear. However, it will probably be impossible to find replacement gear sets, Royal Products- unfortunately- very unfortunately- closed their doors about 5 years ago.
2 Piece

RE: Royal Servo
 

Thank you all for your replies. Well, I have no idea what those splines are. If you guys don't mind, can you give me a rough sketch of what they are for? And it seems like those servos are quite old (and so is the plane that they came with), I'm surprised that they still work. (Like my mom always says, old houses are more durable than new ones). And I guess 2 piece was right, that could've been a lion pattern. Sorry it's small so too hard to tell. I actually got two different sizes after taking a closer look. I'm guessing they are standard and mini by comparing their dimensions to modern servos. How could people tell what size and model these serovs were back then? Or maybe there were only a few manufacturers and servos kinds so people could easily tell?