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[terry1956]

Hi, I am trying to make a mechanism that will allow the periscope to rise and lower by radio control. However I can?t think of a way to limit the movement of the motor. I have been told there are switches that can stop the motor, but I have not been able to find any. Can someone please advise. I am in the U.K. thanks

[Circlip]

In the trade, they used to be called Limit switches. Basically Micro switches.


 Regards  Ian.

[terry1956]

Thanks for getting back, who sales these

[GG]

terry1956,
            Read all about Microswitches in the Tutorials section of this site.
         
            Glynn Guest

[DominicS]

you can use microswitches and diodes to do this, like in this video

https://www.youtube.com/watch?v=Nn93Me-p18s

[dodgy geezer]

Hi, I am trying to make a mechanism that will allow the periscope to rise and lower by radio control. However I can?t think of a way to limit the movement of the motor. I have been told there are switches that can stop the motor, but I have not been able to find any. Can someone please advise. I am in the U.K. thanks

You could do this electrically, by putting micro switches at the top and bottom of the periscope slider so that one direction of the motor is switched off when the slider end hits a switch. You can do this mechanically by having a slipping clutch, or using a screw thread where the runner comes off the thread at each end of the run. You could set the mechanical movement driven by a servo or solenoid, such that the maximum throw is within limits for the periscope movement. There are lots of ways to achieve your aim.


It would help if you could put a drawing up showing the sort of structure you have at the moment, which would let us suggest the easiest way to handle your requirement...

[terry1956]

Thanks chaps

[Big Ada]

All very technical, why not just use a Servo on its side ?.
  Len.

[Circlip]

Or the servo right way up and a belcrank


 Regards  Ian.

[tassie48]

Terry1956 years ago I had a type 7c in 1/24 scale I used a micro servo with a sewing bobbin that I rigged as a winch with cork straps to allow it to float up winched out and  winched it  down and submerged I heard the new owner used a push pull rod via  a servo to control it now just my two cents worth tassie48

[Akira]

All very good information, but I would assume that this is needed for a submarine and, if so, that part if not all of the mechanism will be in the "wet" which can be challenging if electrical. There are several other ways of achieving what you want. Using a servo makes for an easy way to seal the pressure hull and the throw can be adjusted with bell cranks.One is a free floating 'scope that is raised by a float when the boat submerges, and lowers when it surfaces.Another is to use hydraulics to raise and lower the scope. A servo pushes on a piston(syringe) that is connected to another "syringe". The scope is part of, or connected to the piston of the remote syringe.Third, I have used micro air cylinders that worked similarly to the above method. A compressed air supply is needed, or, the ability to pump air from within your pressure hull to raise the 'scope. The air would be held in place by micro solenoid valves and returned to the pressure hull upon opening of the solenoid. A spring returns the 'scope to the down position.

[Akira]

I forgot to mention the Hall effect approach to limit motor rotation. It is probably discussed in other threads.

[philk]

Possibly a waterproof linear actuator