wing servo for f-14
11-02-2018, 09:45 PM
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wing servo for f-14
so my fiberglass fuse is almost done for my 1:10 f-14 turbine based on avonds plans and looking at the wing is pretty thin. i want spoilers flaps and slats so i was wondering if the mks wing servo are strong enough to move spoilers at 144oz of torque. being the taileron servos are 540oz and they do pretty much all the job will i get away with maybe two small servos per spoilers for a combined 288oz??? any help or pointers apreciated
11-03-2018, 07:04 AM
#4
I'm not personally familiar with the jet honestly. It was the same size as the jetmart F14 and close I believe to the yellow aircraft F14. Are spoilers part of the design on that kit or are you just adding them?
we tend to way over power our surfaces but more power is better than not enough. I am just assuming really that one servo would be enough per spoiler but if it makes you feel better, or if the spoiler flexes with only one linkage connection then put 2 on it. When that jet first came out for ducted fan some of the most powerful servos you could get were only around 150oz. Your stab servos for example that you are using are probably 3x more power than necessary. Use them as it will definitely give you peace of mind but we tend to think we need far more power than we really do. How big are the spoilers and how much deflection do they have?
we tend to way over power our surfaces but more power is better than not enough. I am just assuming really that one servo would be enough per spoiler but if it makes you feel better, or if the spoiler flexes with only one linkage connection then put 2 on it. When that jet first came out for ducted fan some of the most powerful servos you could get were only around 150oz. Your stab servos for example that you are using are probably 3x more power than necessary. Use them as it will definitely give you peace of mind but we tend to think we need far more power than we really do. How big are the spoilers and how much deflection do they have?
11-03-2018, 07:20 AM
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spoilers where on the plan but only drawn not really a fonctioning and without specific way of actuating them. they have about a quarter inch deflection and are about 14 inches long.
11-03-2018, 07:24 AM
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also on another note im looking for the aluminum horizontal stab assembly where the servo bolts on and theres a rod with bearings. thinkin of cncing that from aluminum but if there an already made one i can buy it would save time.
11-03-2018, 09:03 AM
#10
I would think so, but remember, I have never had this jet so it's just opinion. I look at a jet like my BVM Kingcat, it will do well over 200mph, it has massive flaps, and the servo's again are just the old JR 2721s at 148oz of torque. They have more than enough power to hold them in the up position and flaps are not deployed at high speed. If I hit flaps on that jet at 200mph it would destroy the servo's and probably shear the flaps off the airplane if not destroy the wing, so your servo power is definitely related to it's use. The flaps on the kingcat have far more surface area than the elevators, yet require less torque because they aren't being used at high speed. Take a look at what the Skymaster F14 is using for servo's on those same surfaces. That jet is significantly larger than the Avonds so if you look at those servo's and are anywhere near the power of what they recommend you will have well more than enough.
11-03-2018, 09:12 AM
#11
Personally, on the Avonds F14, at the size it is, I would be more concerned about the added weight that adding all of those things will bring to the airplane than the torque of what servo's are needed. I would personally be keeping it simple with elevons like it was designed and not worry about slats and spoilers etc.
11-03-2018, 10:51 AM
#12
Dont waste your time with slats or spoilers on that size F14. The complexity is already bad enough and the Avonds plans designs dont work very well for the spoilers/slats as drawn. The 1/7 was bad enough to get everything “stuffed” into the wings for all that stuff and they are hollow molded composite parts, doing it all in a foam core or built up wing would be extremely difficult. The pivot structure design on the build up wings as designed is also a failure point as well.
Also a 1/4” deflection if the spoilers makes them even less worthwhile to do them, the full scales extended nearly 90*.
But, to answer your questions, with only 1/4” deflection , a pair HS81MG servo’s on each panel would suffice bc i doubt you’ll be able to keeo the panel from twisting with only a single servo.
Also a 1/4” deflection if the spoilers makes them even less worthwhile to do them, the full scales extended nearly 90*.
But, to answer your questions, with only 1/4” deflection , a pair HS81MG servo’s on each panel would suffice bc i doubt you’ll be able to keeo the panel from twisting with only a single servo.
11-03-2018, 04:49 PM
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yeah thanx invertmast for the infos you are right about keeping weight down on that size. i got a fiberglass fuse made from the wood plug so i save a bit there and the wings are not the built up ones like on plans but rather the same as 1/7 composite hollow mold. im trying to build myself a nice plane without needing a van or trailer to go fly it. being twin turbine also makes it less expensive to go smaller thats why.
