Hello friends ,I got a project in which I have to perform swivel mechanism(rotating swivel of 30 kg)...here I am using motor to swivel gear arrangement (1:4 teeth ratio)so that small motor will be able to rotate it...and sonar system for obstacle detection but the main problem is that I hv to stop it in a particular direction(multiple points and point will be fixed at site point and bot should completely automatic)so suggest me any specific idea for it....not using wheel encoders????

 

Assuming that you are using a microcontroller, use a stepper motor, so you can use the step/direction to know the sonar's position.

Ken

 

Unless you have a very powerful motor I think you'll need a gear ratio much greater than 4:1 to rotate a 30kg load in a controlled way.

 

#KMoffett sir really thanks for your suggestion.
Sir but if we vl use stepper motor then it vl unable to lift the 30 kg load of swivel to whom it is rotating ...

 

#Alec_t sir I appreciate your idea but sir gear ratio of motor to swivel as 4:1 is not a practical idea.... Am I right???

 

gear ratio of motor to swivel as 4:1 is not a practical idea...

That's what I was suggesting. I'd use a much higher reduction ratio (e.g. 1:400?). How fast does the sonar have to rotate (rpm)?

 

#KMoffett sir really thanks for your suggestion.
Sir but if we vl use stepper motor then it vl unable to lift the 30 kg load of swivel to whom it is rotating ...

I thought you said you wanted to "rotate" a 30Kg object, not "lift" it. With a 1:400 gear system (per Alec-t) a reasonably sized stepper motor can move 30Kg.

Ken

 

My CNC machine with a 12 mm diameter 8 mm lead screw can push 100 kg with ease, with a standard size 23 stepper motor shaft connected directly to the screw.

If it was a leadscrew with a finer lead, like a 1 mm pitch, it could directly push or lift >500 kg.