Originally Posted by
flywilly
Hi Dan,
Back in the day (early '80s), the torque rating on my Futaba S131 servos was 42oz/inches at 4.8 volts (the only option) and those worked fine in 60 powered pattern ships. Increased torque and speed along with ball bearing supported output shafts provides better resolution. I fly mostly high end digital servos, but still some good quality analog servos in my sport airplanes. I flew an old MK Wild-7 which had old (like 25 years old) but top quality at the time servos (Futaba). The airplane flew fine, but I felt like I was flying in mud because the response was noticeably slower that my other airplanes. Lastly, I have never run 'cheap' servos; so I can't really address their performance or durability. I have servos that continue to perform well after 1,000 flights in a glow powered pattern ship. The engine is soft mounted which is certainly a contributing factor.
My 2 cents worth... :-)
-Will
Hey Willy,
Thanks for the techical information. I think my first fubaba radio for a .40 powerd craft came with those 131s. 42oz is about 2 lbs 10 oz./inch I don't know how to or if I need to convert the inches to centimeters on these little foreign servos I have but the 10 pack I bought on amazon was available in two sizes.. on was 4.5lbs /cm and the other, cheaper ones at 2 bucks a piece (what I bought) will do somewhere around 3.4lbs /cm.
As for longevity, I've been using them quite a bit in my builds and they're doing a great job so far. 3 years running on the same planes with no sluggishness or anything, so I'm pretty pleased overall with their performance. So based on the stall torque you provided, these 2 dollar servos should be more than enough.
I did this video and replaced the stock parkzone servo which was supposed to he sealed (it was not) and was supposed to not short out (it did) and so instead of being stupid and buying a new parkzone servo to stick in the same stupid place where the water pools up when water gets in the hull of the craft, I put one of the two dollar ones in and changed the mounting location, as well as go over how I waterproofed the hull (which caused the failure) with white gorilla glue. Excuse my 10 year old son and his shameless plugs. I tried to let him be my camera man.. well... you'll see how that turned out.
I'm just trying to get him interested in RC flight, and I figured having him help me make movies would be the best way to get him started and interested.
When we get to the inside view of the plane you can see the brand I'm talking about
: I'm hoping the little bit of play in the rudder doesn't affect the as3x or I'm going to need to pull it out and put in a more rigid block of foam, but the play is about 1mm so..