Hey guys. So I've successfully "extended" the components of my servo tester so I can position them inside a spiderman mask easier but I was wondering if any of you with your infinite wisdom could suggest something I could replace the attached picture with. In a certain mode it allows you to move the servo with the dial but i was hoping to have a much simpler button that I can press with my chin etc. If it would be too much hassle to change then I'll probably just make do but better to ask thanks in advance

 

How would you want this button to work?
Wouldn't you need two buttons, one for each direction?

 

I assume you need a chin operated pot to control the servo position?
Some kind of spring operated pot, linear rather than rotary maybe.
Max.

 

@crutschow,

Not if he only needs two positions. I’d measure the pot from wiper to each end, which would give me four values or two voltage dividers. With a SPDT momentary push button switch, he could select one of two dividers, and thus pressed is one position and not pressed gives the other.

 

It depends on how the servo is presently controlled, using a 12F pic you can go to graduated positions from fully CW to CCW in for e.g. 20 positions from one to the other.
Max.

 

Yes, if the TS wants to start over again. So far, he’s decided to use a servo tester module and wants to replace the continuous control provided by a potentiometer, with a way of hard-wiring two positions. Any other servo position is not desired nor necessary.

 

Yeah I'll be using micro linear servos as I only need up and down movement. Whilst the ability to choose how far I want the lenses to close would be ideal it's a little difficult to operate inside my mask. I didn't know if there was another component you guys might know of that could easily replace it or be easier to operate using a chin haha. It was here that I found out about servo testers. So far you guys have been extremely helpful. But yes I technically only need 2 positions. Open and closed.

 

I also apologise in advance for being completely ignorant to abbreviations. So don't feel like you're patronising me. Dumb Dumb language works best with me hahaha. Thanks again for all your ideas. Hoping you guys can find a solution for me.

 

Then you would only need one switch, default to one position, click-on/click-off P.B. switch to the other.
Max.

 

Then you would only need one switch, default to one position, click-on/click-off P.B. switch.
Max.

Yeah that would be ideal. Press - Eyes close. Release. Return to zero or original position.

 

So it could be a simple momentary P.B. if retained is not needed.
Max.

 

So it could be a simple momentary P.B. if retained is not needed.
Max.

What would the exact component name be and would it be as simple as replace it? Sorry for the newbie question style haha

 

https://www.digikey.ca/products/en/switches/pushbutton-switches/199?k=push button switch
Over 171,000 listed!
Max.

 

https://www.digikey.ca/products/en/switches/pushbutton-switches/199?k=push button switch
Over 171,000 listed!
Max.

Fantastic. I'll order one. So what would I have to do to ensure it moves the lenses appropriately? or is it a little trial and error

 

What present control method are you using 555 etc? or Microchip etc ?
Max.

 

What present control method are you using 555 etc? or Microchip etc ?
Max.

Yeah I'm pretty sure the servo tester has a 555 timer in it

 

Do you have a schematic or link?
How is it controlled now? A variable pot?
Max.

 

It was off Ebay. I'll find the link now if you want and yeah at the moment its using a variable pot in mode 2 (it has 3 modes) to control the position of the servo

 

It may be a 555 or a small 8 bit microcontroller... either way main function is to change the pulse width of the squarewave and it's a small package with everything you need.

It shouldn't be difficult to wire up a button to it.

It could be as simple as determining what the max resistance is; then put a resistor parallel with a pushbutton. When you hit the button it gives zero resistance... you will have to play and measure what the pot does to determine the correct values and wiring.

 

One of the best circuits is https://www.servomagazine.com/magazine/article/may2015_Predko
556 based.
Max.