Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: Steve on June 01, 2012, 09:47:56 am
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I have a Hitec sail winch servo, my question is am I able to connect this servo to a three position switch on my transmitter (DX8)
I would like to flick the switch down and the servo go one way until I return it to the centre position and the servo stop were it is.
Then to flick the switch in the opposite direction and the servo go the other way until the switch is returned to the centre.
At the moment the winch goes one way or the other on the switch but soon as you return the switch to the middle the servo returns to it zero position.
Can any one help
Steve.
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The servo will have to stay in either the UP or Down position to keep the sail in either position.
i would suggest driving the servo with a Non sprung arm on the T/X, then it will stay where you leave it.
regards
ken
ps Just had a thought. There are pulse switches which electronically lock with a jab of the TX either on or off but the wiring up would be complex.
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Cheers Ken,
However the sail winch in a sense isn't being used as a conventional winch,
It has a timing belt attached that is connected under the deck to another pulley that in turn is attaced to a forward sail boom that reefs in a genoa sail..I want to be able to control how much the sail is reefed in and out.
Cheers
Steve.
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I figured there was more to this than meets the eye.
Could you put up a sketch of your system for the more knowledgeable guys to browse. It looks an interesting problem.
ken
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Hi
I use a CHEAP Turborix/Hobbyking 2.4 Tx/Rx with turn knobs on channel 5/6 at stay where placed, but also mixed to a switches for quick returns
Timo2
" works for me "
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The sail winch servo is just a servo, albeit a lot bigger, with a drum rather than an arm. The switched channel will send out information just like any other channel, its just that with a 3 position switch, it can send any one of 3 positions at any one time, rather than the infinite number of positions you get with a pot.
Best to plug an ordinary servo into the appropriate slot and do an empirical test, operating the switch and seeing what the servo does. If it takes up positions corresponding to left, center, right, then the winch will do the same, only with more turns involved. Best to try it out of the boat on the bench first.
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I have a aux3 which is a pot, this works fine with one of my other winches, I'm wondering if I could replace my three way switch with another
Pot type switch, maybe I will have to get in touch with Spektrum to see if it's feasible.
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If you use a geared motor with a drum instead of the servo then you can do exactly what you have described with a twin relay switcher - guess who makes those? http://www.action-electronics.co.uk/pdfs/Limit%20Switches.pdf (http://www.action-electronics.co.uk/pdfs/Limit%20Switches.pdf) 8)
MFA-Como Drills have a very complete range of geared motors, one of which is bound to suit this application http://www.mfacomodrills.com/gearboxes/gearboxes.html (http://www.mfacomodrills.com/gearboxes/gearboxes.html)
Dave M
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Thanks for that Dave, as always you come up with a solution.
However the Robbe genoa sail kit comes initially with a geared motor, in fact I ordered one of your speed controllers for it.
But it used a sprocket and ladder chain affair ad it was always jumping the sprocket plus it was a night mare to fit.
All is working well with the servo plus it has a lot of torque. I think I will have a re think of my options and try a re shuffle of my switches.
Thanks anyway
Steve.
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Not sure how to make it work as you initially asked but...if you want to use one of your stick's channels --
If you "hack" it by removing the feedback pot's gear, you can turn it into a directional motor whose speed it dependent on how far you deflect your stick from center. Centering your stick will stop the rotation.
However, when I did it on my large schooner for my tacking jib sheets, I had trouble keeping/finding the electrical zero spot so my winch would slowly pay out or pull in until it stalled.
Landlocked
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Your best bet is to look at www.servocity.com
For sail winch selections in all types of geared models. They are very popular.
You can even by the parts from them and build your own.
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http://www.rcsails.com/sailwinch.html