Hi gang: Back in the 70s we had these and a lot were used for cars on the steering. After many years in the UK trying to get hold of some it seems a tad difficult to even get any one interested in throwing some hope my way. What iv found is not much use at all and very expensive to say the least.
Can the USA point me in the right direction?
cheers n beers. snipped-for-privacy@btinternet.com
Go to Electronic Model Systems / JOMAR Products site. They have what you want. Harry
Cheers Harry they are on order.....hope the import tax aint steep!!
You won't be disappointed. They sure do make a difference, no wiggle, just straight forward and back.
But an interesting point that many do not think of, is that, when using a linear servo, the control surface response to the transmitter stick input becomes non-linear.
In other words: If non-linear response is your problem, using a linear servo may very well make your problem worse.
The problem is when throttle servos use a snake what ever and rub against the tank. though this aint no major problem id like to fool about when the space is tight. Plus id like to try a couple on ailerons just to see if i can tell the difference. A bit of fun if you like and it wont break the bank.
Its mainly for arms that click or foul on stuff ya wanna stay clear of.
happy rolls. steve UK.
huh?
You will get non-linear travel for a throttle servo ( for example)using a rotating servo (slow travel at the top and bottom travel of the circle, and faster travel in the mid-range), but with a linear servo, each gear tooth drives the arm exactly the same speed. (at least these do).
But at the other end (the carburetor), the throttle arm moves in a circle as well. If the arm length on the servo is the same as the arm length on the carburetor, you get perfect linear response between servo and throttle body. Otherwise not.
Using throttle as an example is not ideal, as engine power is not linearly proportional to throttle opening anyway, but you get the idea.
I don't know about that Rob, Having two non-linear movements making up into a linear movement concept doesn't ring true to me, but regardless, the point of a linear servo is that you don't have to worry about a deflection of the pushrod/ wire/cable/goldenrod from side to side in a tight servo mounting spot, like being close to a bulkhead. They (linear servos) are especially useful for operating air valves for retracting gear with a short wire travel. Air valves don't like a big wiggle. Harry
That does not make it any less of a fact.
That is true, but compared to all the other disadvantages, there are extremely few situations where a linear servo is the best choice.
They do, however, have only one travel length. With a rotary servo, you can increase strength (sacrificing travel length) by shortening the servo horn, or you can increase travel length (sacrificing strength) by lengthening the servo horn. If your gear mechanics require only half the travel of the linear servo, you must reduce travel electronically, which gives you no increased strength. You may, in other words, end up needing a bigger, heavier and more expensive servo.
There's also the precision issue. A linear servo will always have more slop and wear quicker than a ball bearing rotary servo.
So, yes, they are easy to install and set up, but because of the range of other problems and quirks they pose, nobody is buying them anymore, and therefore, nobody is making them anymore either.
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