Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: andyn on February 20, 2009, 02:22:25 pm

Title: Oh dear, which wire to cut? Mission Impossible moment...
Post by: andyn on February 20, 2009, 02:22:25 pm

Wanting to convert a servo to a winch, by cutting out the Potentiometer. I'm pretty clued up on how to convert servos, but I want to keep it all in the original box, and as the pot supports the final drive, it will need to remain in. Question is, can I just cut the wires and be done with it, or do I need to solder two of them together?

(http://i288.photobucket.com/albums/ll184/andyn_01/DSCN3530.jpg)
(http://i288.photobucket.com/albums/ll184/andyn_01/DSCN3531.jpg)

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: John W E on February 20, 2009, 02:28:41 pm

Hi Andyn
this may help you out
http://www.kronosrobotics.com/an116/GAN116_3003.shtml

john e
bloobs

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: andyn on February 20, 2009, 02:38:33 pm

Thanks very much :-))

Just had a look at the geartrain after reading that, and the servo I'm using is far more simple, and all I have to do is lop the top of the Pot shaft off and it *should* work...

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: andyn on February 20, 2009, 03:03:39 pm

Success :-)) Thanks Bluebird O0

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: Martin (Admin) on February 20, 2009, 05:02:19 pm

... and he's got clean fingernails!  :-))

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: andyn on February 20, 2009, 06:00:12 pm

Yup, thankfully it was full of silicon grease which does have a cleaning effect O0

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: Umi_Ryuzuki on February 20, 2009, 07:35:05 pm

I drill out the gear that sits on the pot shaft,... same effect, the pot can not be driven.
But I also plug the servo in, and center the transmitter sticks and trims, and then turn
the pot till the servo comes to a stops. Then I apply a drop of cement to the pot shaft
so that it will no longer shift.  :-)

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: andyn on February 20, 2009, 08:28:03 pm

My servo was an old one, and very simple, the pot shaft was about 1/4" long, with a flat filed at the top. cut the flat bit off and it went into free rotation, then I had to take the end stop off, which involved filing some new teeth into the gear. Now rotates happily making a low humming noise. If it had a face, it would be rather cheerful O0

Title: Re: Oh dear, which wire to cut? Mission Impossible moment...
Post by: malcolmfrary on February 21, 2009, 12:03:21 pm

Some servos drive the pot via an insert in the bottom of the main output gear - this is even easier than drilling out. 
If you prefer, the pot can be removed as it does no supporting. 
It can be an advantage to re-site it where it can be got at without removing and stripping the servo.  some pots are held by friction, some have a collar nut, some are clipped in.