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[frogman3]

as the title says as im tryin to make my gun turret turn can any one help me
chris

[ballastanksian]

Hi Chris,


The options fall into Direct mechanical and indirect mechanical with digital options.


Direct Mechanical is where you mount the turret onto a servo in some way and this turns the turret within the limits of the servo* You can use a stepper motor in the same way using a computer or ESC control.


Indirect Mechanical is where you either use two gears, one on the servo/motor and a larger gear on the turret, or you use a belt or cable and pulleys. The latter can be used to control a number of turrets at once, but you have to make sure they do not revolve too much and hit superstructure or other turrets.


Digital control using say Arduino or Raspberry Pi mini computers allows you to use stepper motors and program speed of rotation and traverse limits.


Have a look at Battleship builds especially those by Geoff (HMS Iron Duke, Invincible etc) and also there is a build log here of HMS Rodney by C3PO HMS Rodney (modelboatmayhem.co.uk)


A lovely chap called Bob K was/is working on a model of HMS Agincourt and he did lots of development along side Geoff and C3PO. I recall stepper motors being involved.

[ballastanksian]

An option might be if you can get hold of toothed printer drive belt and gears from an old printer


If you can work out the circumference of your turret ring and then cut the length of drive belt to complete teeth length you could glue this around a wooden or plastic disk to create your large traverse ring, and then use a drive gear on the servo/motor.

[GG]

frogman3,
             Have you looked in the Tutorials section, "Pulley Power"?   It might give you some ideas.
Guess you don't want to use a Sailwinch servo, perhaps with extras to limit and slow its travel.
Glynn Guest

[Rob47]

as the title says as im tryin to make my gun turret turn can any one help me
chris

Chris
look at mikes page for an item call turret servo control, I use this and it sorts all the problems using a servo. mount turret on servo with the module beteween it and rx, then set it up.  You can adjust speed of traverse and the bets bit is when you let go of the stick the turret stys there unlike with a normal servo set up returning to fore and aft.  Its dead simple alost plug and play, not find better.


Bob

[Geoff]

As an alternative you can use servo sized sail winches as they have more than 180 degrees travel. You can either control the throw by adjusting the transmitter and even speed (if you have a sophisticated set up). There are also servo throw devices available which will work.


Theoretically this will give you automatic beam to beam with return to center line. In practice I find a little tweak is need due to the electronics in the sail winched having a tiny dead band.


If there is not room directly beneath a turret you can use the same winch set up remotely with a toothed belt or used fishing line (which I do) . You fix the fishing line permanently on the center of a wooden or plastic wheel/drum beneath the turret so it can't slip. You can also use Bowden cables if the winch has to be really remote as that works as well.


Be aware that to get to 95% accuracy may take x amount of effort, to get to 100% accuracy will take 100 x effort!!


Cheers


Geoff

[John W E]

Hi  have a look at this , it may help you


how to make a working gun turret (modelboatmayhem.co.uk)


john