Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: timgarrod on October 06, 2016, 12:39:37 pm

Title: Turning Search light
Post by: timgarrod on October 06, 2016, 12:39:37 pm: Afternoon all,

I want to make the search lights on my bermpohl turn. I was just thinking of replacing the the servo disc with a gear and same on the search light post. Does any one know if you can buy gears that fit directly on servos or is there a easier way.

cheers
Title: Re: Turning Search light
Post by: C-3PO on October 06, 2016, 02:31:24 pm: Tim,

Google, robotic servo gears or permutations

Maybe something from here - have not had a detailed look

http://www.robotshop.com/uk/gears-belts-pulleys-tracks-sprockets-chains.html

C-3PO
Title: Re: Turning Search light
Post by: timgarrod on October 06, 2016, 03:31:44 pm: cheers,

Will check them out.
Title: Re: Turning Search light
Post by: C-3PO on October 06, 2016, 06:03:57 pm: Tim,
Another link https://www.proto-pic.co.uk/search/for/servo+gear/

Once you have found what you want you may well find eBay or googling for product come up with a much cheaper alternative for the same thing!

C-3PO
Title: Re: Turning Search light
Post by: timgarrod on October 06, 2016, 07:48:46 pm: Cheers Again C-3PO.

Book marked both sites. think i've found the bit i need :-))
Title: Re: Turning Search light
Post by: Subculture on October 06, 2016, 08:00:15 pm: Why do you need gears for that? Can't you just actuate the light directly from the servo shaft?
Title: Re: Turning Search light
Post by: nivapilot on October 07, 2016, 08:42:16 am: Quote from: Subculture on October 06, 2016, 08:00:15 pm
Why do you need gears for that? Can't you just actuate the light directly from the servo shaft?

Only if you want the turn of the light limited to the angle of rotation of the servo.
Title: Re: Turning Search light
Post by: timgarrod on October 07, 2016, 09:00:54 am: Cheers Andy, did think about it but didn't think I could a attach it to the servo shaft easy.
Title: Re: Turning Search light
Post by: Subculture on October 07, 2016, 12:24:37 pm: You have a thread in the servo spigot, just run a metal shaft into it, and run a lock nut up (be best if it's a metal geared servo). Then you can just attach that shaft to a spigot on the searchlight with say a rubber tube coupling.
Title: Re: Turning Search light
Post by: timgarrod on October 07, 2016, 12:37:58 pm: Hadn't thought of that. Cheers Andy :-))
Title: Re: Turning Search light
Post by: minimariner on October 07, 2016, 08:19:35 pm: Tim,

Component Shop sell a 360 degree servo, or you could use the Action Servomorph P96
to slow the servo and stretch the end points. Hope this helps.

Bryan.
Title: Re: Turning Search light
Post by: timgarrod on October 07, 2016, 08:37:14 pm: cheers Bryan,
Title: Re: Turning Search light
Post by: Subculture on October 08, 2016, 08:38:31 pm: Do you require 360 degree rotation? Most servos can easily do 180 degree, and up to 270 degree with some modification to the internals, removing the mechanical stops on the gears. The limiting factor then is the feedback potentiometer. You will need a pulse stretcher however.

An alternative is to remove the feedback pot, and just operate things bang-bang.
Title: Re: Turning Search light
Post by: timgarrod on October 08, 2016, 09:26:05 pm: Yea, already modded the servo today to make it do 180 if needed. can't see needing 360 movement. might convert another one for 360 tomorrow for the anchor.
Title: Re: Turning Search light
Post by: derekwarner on October 08, 2016, 10:36:25 pm: Tim........irrespective of the rotary position increase you could consider the need for slowing the speed of movement

I use Action Servomorph P96 for serious work [where I consider totally repeatable positioning critical], however for a simple function as swivelling a searchlight these SJ units offer cost effective controllers worthy of consideration

Derek