Why does it matter to a servo whether the command is relayed over a remote control system?Unfortunately OP hasn't provided info on the actual servo in use, nor on the actual application, and only little information on why he would want to do this.
Why does it matter to a servo whether the command is relayed over a remote control system?
hat just doesn't make much sense as you always know where a servo is: at the position you tell it to go
Reread the previous post. Nobody said anything about remote control.The wording used was "Radio Control"If you have never used radio control then perhaps you should Google "Radio control servo"If you are an experienced radio control hobbyist then you already know that the arduino usesthe Servo Library to talk to RC servos and also that RC servos are a specific form factor that uses RC servo "Arms" that plug onto the servo shaft. If, however the servo is NOTRADIO CONTROLLED (at this point it is irrelevant that radio control is in fact a form of remote control since the discussion is about form factor and programming) then the term "servo motor" means something completely different, which I might add, your typical RC hobbyistwould have no experience with , since a typical industrial servo motor costs hundreds ifnot thousands of dollars, especially if equipped with absolute encoders. Even the ones with incremental encoders are expensive. RC SERVOAC BRUSHLESS (NON-RC) SERVOSo, in conclusion, the difference between "RC" (which stands for RADIO Controlled, NOT REMOTE controlled) and "NON-RC" is the difference between $16 USD and $622 USD.So yeah, it does make a difference. It's not about whether it is REMOTE controlled or NOT REMOTE controlled, it is about WHAT KIND of SERVO we are talking about.If we were talking about RC servos, (which we are not) then we would ALSO be talking about the SERVO library which , (as already pointed out) takes a position argument in the command so you know WHERE (what position) you are commanding it to .If , on the other hand we are talking about industrial servos, then knowing WHERE the shaft is requires a whole other approach, hence the OP's request for a way to couple the motor shaft with the pot shaft So if you have this:INDUSTRIAL AC SERVO MOTORyou can couple it to this:POTENTIOMETERusing this:SHAFT COUPLERThere is of course the caveat that you must write you software to NOT allow the motorto attempt to drive the pot PAST the END-STOP.And just for the record, we have not yet discussed AC vs DC regarding servo motor type.It is unknown at this time whether an adaptor will be necessary since the pot shaft diameter and the motor shaft diameter remain unknown.
Must be dc. 12v
That covers everything from 1 cm to who knows how large.Can you narrow it down by adding the current rating ? (or motor size in mm ?)What about this ? (you also haven't mentioned speed criteria (degrees per second etc)
I will need to convert the motion from the servo to linear. Putting an arm on it would work.
Consider a linear actuator in that case, may be the better tool for the job. There are linear actuators with location feedback. Some can even be addressed in a manner similar to servos.To measure the force needed attach a spring scale and start pulling, see how much force you have to apply to get it moving.
How much torque required to turn the valve? How many degrees from full open to closed? Have you thought about proportional flow hydraulic solenoid valves?
To a certain extent, some of the information can be obtain by simple manual testing.Example, you have a valve that has a shaft. You clamp a pair of vise grips on the shaft and open and close the valve by hand. Then you remove the visegrips from the valve and clamp on the motor shaft and turn on the motor and tell it to turn (slowly) one way or the other , then you try to stop that motor from turning by holding onto the vise grips and mentally compare the force needed to turn the valve with the force needed to stop the motor.Additionally there are other more accurate ways to measure the torque, like attaching a pully to the shaftand having the motor lift a weight, (like a bucket you add or remove water from and then weigh the bucket. ) The converse of this is attach a pulley to the shaft of the valve and measure the weight of the amount of water needed to open and close the valve and then see if the motor can lift that amount of water (or sand, or rocks, or diamonds, or coins etc) At the end of the day, you don't need to know the torque spec in Nm. All you need to do is find a motor that is capable of performing the required task and then look at the spec sheet for that motor and whatever it is , it exceeds the torque spec for you task.
birddseedd, when will you stop opening threads in the forum before you have figured out what you want?You want to control a valve both by hand and by a motor, right?You didn't even use the word "valve" before your FIFTH post and another TEN answers from users that spent their time trying to help you.