90 degree turn servo and controls

[danfick]

hi

I'm new to the forum but my research suggests that you are the people to ask about an electronics project. I am trying to build something that will house up to 8 servos that will need to turn 90 degrees, hold for 3 seconds and then turn back. What would I need for this? Can I get the servos programmed before the sequence starts or would I be best to manually initiate each one?

Thanks in advance for any help you can offer me

Dan

 

[(*steve*)]

do all the servos need to move at the same time?

Or do the need to move independently?

 

[BobK]

Hi and welcome to the forum!

A servo requires a specific repeating signal to hold at any given position. Servos are not not programmed. You could program a microcontroller to do what you want, or a fairly simple circuit with 2 555 timers to do what you are asking.

I have no idea what you mean about manually initiating each one. Under what conditions do you want to start the sequence? Is it a push button, a particular time, or another signal coming from somewhere else?

Bob

 

[danfick]

It is for a shooting competition and the appropriate target costs around £2000. We need to have a random sequence of targets turning for 3 seconds with gaps of 5-20 seconds between each turn.
This is the target and it looks like an easy build except for the electronics

http://www.boards.ie/b/thread/2057456190

 

[duke37]

I would think that a solenoid, which only needs turning on and off, would do the job of a servo. You will need some way of producing a random signal. Have you thought about this?

Will you be picking up all the lead shot? I am discouraged to use a smidgeon of lead in solder.

 

[Alec_t]

A suitably programmed MCU could take care of the timing functions and actuator driving. However, you would need to provide an impact-buffering mechanism between each target and its actuator (/servo) to reduce impact forces; otherwise the actuators will have a short life.

 

[danfick]

The targets will be thin corrugated cardboard so there will be no shock as the round hits. The bit I'm struggling to get my head around is exactly which components I need

 

[Gryd3]

The targets will be thin corrugated cardboard so there will be no shock as the round hits. The bit I'm struggling to get my head around is exactly which components I need

Hi and welcome to the forum!

A servo requires a specific repeating signal to hold at any given position. Servos are not not programmed. You could program a microcontroller to do what you want, or a fairly simple circuit with 2 555 timers to do what you are asking.

I have no idea what you mean about manually initiating each one. Under what conditions do you want to start the sequence? Is it a push button, a particular time, or another signal coming from somewhere else?

Bob

You can also take a look at some hobby stores.
Servos are incredibly common, and there are a TON of resources out there.

If you are looking into servos, I would suggest you look here for some quick info : https://www.princeton.edu/~mae412/TEXT/NTRAK2002/292-302.pdf

Additionally, there are lots of other methods you can use... Servos are great when you need specific angles, turns, etc... if you just want something 'open' or 'closed' you can use solenoids, regular DC motors (with or without limit switches), or even pneumatics. (You can get voltage controlled pneumatic valves)

These other methods require a simple 'on or off' signal instead of trying to control the specific signal. I would only look at servos if the target needed variable positioning... or perhaps needed to move while 'exposed' to offer a challenge.