Help needed with electronics questions.

[mcostello]

I would like to design an electronic switch setup to move a small - 6V- electric motor a small distance then stop and turn on another small electric motor to start a small low speed motor. The original motor would then have to move back to "home" position. How could I accomplish this? My non electronics mind thinks it would need several micro switches. Adjustable duration of starting time would be nice. Am I shooting for the moon, or is this doable? Anyone have a direction to point Me in?

 

[RonGinger]

The nice way to do it would be with an arduino. If the motor is under 2a there are a couple nice 'shields', thats a board that just plugs on top of the arduino so no wiring is needed. You could have very good control of the timing of the motors, and not need to make adjustable limit switches.

You can now get arduinos at many Radio Shack stores, and there are dozens of good books, many on-line video tutorials, and lots of web based info.

You could of course do it with just limit switches and wiring, but what fun would that be?

 

[canadianhorsepower]

after the first one is back home, how long is the other one running for.
If all the distance are not going to be the same at all time, micro switch and relays
would be your answer.................unless you know how to program any " Pic board" on the market
good luck

 

[Cogsy]

I'd vote for an arduino board as well. I recently bought a couple (they're cheap) and started to learn the programming. With a good starter book it's not overly difficult and you can do almost anything with them. I'm in the process of building a spiffy 'time fountain' and I've written the code already, gathering the hardware is what's slowing me down (anyone got a spare flux capacitor??).

 

[mcostello]

This project would be used to start a small Stirling fan, the time the second motor would run would be the same every time as would the distance traveled. This is model related that's why I posted on this forum. The fan would be mounted away from the wood stove. I don't want to ruin the engine if it does not start every time.

 

[tornitore45]

There is no reliable correlation between power ON time and distance (turns).
Variable such as supply voltage, friction of all mowing parts, oil viscosity etc..
After several cycles it would be pretty out of phase.

If you place hard stops, provide extra ON time, limit the motor current and the drive can survive a short short circuit then the extra ON time can cope with the variability.

 

[nfk]

Why not using stepper motors? (AND an arduino or pic micro controller)
You won't need any switch, just some math to calculate the steps it need to move.
You can even program the speed and direction to control both motor sequences.
I can quickly write some code examples if you need.

Norberto

 

[Hugh]

If I were doing the work many many many years ago. OK add another many years ago. I would be adding gears to drive cams to operate switches which would control power and timing of the motors. The first one once manually started, or timer started would start running and bump a start switch on the next one. The first one's stop switch would also be set on and if using DC power the power wires could be reversed by the bump. The second could do its number. Cams could also make it reverse and in returning bump and restart the first one. Cams are the first programming language ever invented. They can manage a lot of functions. It just takes imagination. Oh, yes, cams can also power/control wheels! Have fun however you solve your problem.

 

[mcostello]

Any wy I go it's going to be a learning experience. I am wondering if a basic Lego kit would have some of the basics as when watching videos they seem to be capable of many types of movement.

 

[Hugh]

When I was in Milwaukee I saw a mechanical chiming and striking clock made entirely out of Legos. Lego blocks can help prototype your basic mechanical construction. Electrical and computer operation, I wouldn't know about other than if some aspect of the mechanical which might need altering can be simulated easily with something which can be quickly altered such as Lego's and Tinker Toys. This would proof a theory before committing to machining an actual part or changing electronic parts/programming.

 

[mcostello]

The load would be small and not very long duration. Legos might do it, did not know they were so expensive. Evidently kids toys cost as much as our "adult" toys.