bsamuels

I'm new to the RC stuffs, and Ineed a servo to rotate 180 degrees instead of the 90 degrees which it currently does. The servo (http://www.modelspot.com/mpx/ecoservo.htm) was originally installed as an altitude control on an aircraft, and only needed to rotate 90 degrees to furfil its requirements. I believe that this servo can go 180 degrees, but the controller (http://www.servocity.com/html/neon_fm_systems.html) is limiting it by not transmitting the frequencies required to do full 180 degree turns.

SO since the remote control seems to be entirely integrated, is there something I can connect to the servo's control wire that would take the input from the controller and interpret it in a 180 degree range instead of 90, effictively converting the servo to 180 degree control?

Thanks for your time and consideration.

freeair

thought of buying a Sail Winch Servo ?

Campgems

It is not likely you will get a 180 degree servo to work with that TX.

Servo 101, short version. Almost all serovs respond to a Square wave signal from the receiver. I'm not sure the exact length of the signal, but for arugment sake we will say that it is 100Micro seconds at netural. At full travel in the - direction it would go to 50 microsecodns, and for full travel in the + direction it would be 150 microseconds. The pulse width is controled by the tx stick movement. How the servo responds to this signal is simply a mater of gearing and the feedback pot on the out put shaft. Some servos, IE winch servos have more travel than a regular servo. and are proportional. Other servos like a Retract servo are binary, IE full movement in one direction or the other and they are not porportional. THey require an "off-on" chanel on the TX, This is usually on at TX of 6 or 7 channels and is designated for "retracts"

What is your application that requires 180 degrees of servo movement? If you require a given length of travel, you can use different length servo arms to give that length of travel with the normal 60degree servo movement. If you require an over the center lock, then a retract servo is what you want, but I'm not sure one will work with that TX.

Don

redfox435cat

you have to buy a servo set up to rotate 180.

I modified a couple servos to turn 180 degrees years ago.

Get a couple cheap servos. I forget the actual value since it's been 10 yrs but you cut the pot leads and solder a 1/4 watt resistor in there place. The values are something like 1.1k to 3.3k. So again get a cheap servo and experiment. make sure to mark that servo and doubly mark the first test servo since it'll most likely be garbage for the first one and don't use it for something important until it's proven but experiment away, it what make the hobby fun

or the lazy mans way[link=http://www.servocity.com/html/180o_servo_stretcher.html]signal modifier[/link]

I have yet to see any radio that does this, you can set the end point on to 120% on most computer radios and get 110 degrees

freeair

as i posted. forget the mumbo jumbo stuff just by a sail servo.

bsamuels

Quote:

What is your application that requires 180 degrees of servo movement?

Cybernetics project, I'm working on a bot where this servo will control the steering wheel, and I need it to be able to turn on-the-spot so the computer won't have to do additional calculations on its position.




So if Iuse this device with a regular stock servo, let's sayhttp://www.servocity.com/html/hs-56hb_sub-micro.htmlwith the little Rotation dropdown at only 90 degrees instead of the 180, will it be able to traverse the full 180 degree turn, or is it required that the servo be modified however they do with the dropdown menu in order to work with the signal modifier?

redfox435cat

just plug that device into any standard servo, the travel will increase to 180 degrees

bsamuels

thank you!

redfox435cat

depends on the motor and application but yes the power output will decline as the same percentage of inout.

A.T.

Many servo are limited by a mechanical stop or teeth around just 120 degrees of the output gear. However, most others are easily converted. Several pictorial DIY are listed under
"Radio Systems, Accessories, Alterations and FAQ."
sub Sections
"Servo - Alterations, Calculators, Databases, Leads, Repairs, Convert to an ESC or winch & FAQ."
"Servo - Modify for Retracts, Number of Turns, Ganging, Reverse & Continuous Rotation "
"Servo - Digital Servo Programmers and Software"
at:
Alan's Hobby, Model & RC FAQ Web Links
For small servos, easiest solution is to buy a Hitec Digital servo and the small HPP-21 programmer and set exact throw required.
Regards
Alan T.