Circuit for motor and threaded rod

I need a little help with a circuit to run a motor attached to a threaded rod in 3 diffedrent ways. This is kind of hard to explain so I attached a simple drawing that I hope will help. Any questions let me know. Thanks for the assistance.

what kind of motor are you using? (Stepper, servo, regular DC ect.)
you'll probably need a microcontroller to do all of that, and you will possibly need some sort of switches to indicate where the traveler is located.
You may be able to avoid the switches by just using a stepper motor. You could just count the number of steps needed.

Sounds like a pretty difficult task.

I would love to use a stepper or servo motor but I'm not very familiar with them and the circuits that run them. What I have available to me right now is a regular DC motor that will run on 3 - 9 volts.
These are 3 different applications I'm workiing on. I was thinking that for the first 2 that micro switches might be able to be put on either the traveler or the ends (stops) on the thresed rod. I'm just not sure how the wiring would be. The third application I'm not sure how it could be hooked up. Just looking for something as simple as possible.

crunch53 said:

I would love to use a stepper or servo motor but I'm not very familiar with them and the circuits that run them. What I have available to me right now is a regular DC motor that will run on 3 - 9 volts.
These are 3 different applications I'm workiing on. I was thinking that for the first 2 that micro switches might be able to be put on either the traveler or the ends (stops) on the thresed rod.

Click to expand...

Yes, the first just needs end stop switches, and suitable wiring, to do it with a single button will require some logic circuitry - but to do it with a simple toggle switch is only wiring.

I'm just not sure how the wiring would be. The third application I'm not sure how it could be hooked up. Just looking for something as simple as possible.

Click to expand...

The third is FAR more complicated, you need to generate a signal from the motor representing the number of turns it makes, there are various ways of doing this, a slotted disk and opto-sensors is a common way. The rest of it would be greatly simplified with a micro-controller. As already suggested, a stepper motor would make it easier, as it moves a specific amount each step - again, a micro-controller would make it simple.

Do you have any idea of how to wire the first 2 up?

crunch53 said:

Do you have any idea of how to wire the first 2 up?

Click to expand...

It would help a lot if you tell us what end use you have for this device.

For example, it reminds me of the electric ram I recently had to fix. the "traveller" was the ram rod and the screw within pushed it in or out of the housing. It had a novel way to determine when it reached the end of travel and stop. The screw was attached to the motor with a coupling that was slightly (spring) flexible, axially. As the "traveller" nut reached the end it would push the shaft one way or the other and this activated a micro switch, which in turn stopped further motor rotation in that direction but allowed rotation in the opposite direction. The neat part was that both micro switches were located at the motor end of the screw, essential for the ram application.

If you have reasonable axial loads (push/ pull) on your "traveller" then you should fit compression bearings to the motor/ screw coupling, most motors cope poorly with axial shaft loading if they are not designed for that.
Klaus

This is nothing special or heavy duty. #1 is for a Christmas display that I would like to have a figure move back and forth continuously. #2 is pretty much the same except a button would have to be pushed for it to move in the other direction. In #3 the motor is actually attached to a small auger and I want it to turn only a certain number of times and then stop until a button is pressed again. In each of these the unit would only be about a foot by 4” by 4”.

Mike

One way to deal with the "5 turns then stop" might be to use a 5 to 1 gear reduction or timing belt drive. You'd be stuck with a fixed ratio but it's a way. I'd consider some kind of turns indicator on the shaft.

While there is a way to hard wire something like this with limit switches and relays (some of them latching, maybe) it's probably easier to do electronically - either with a PIC or similar microcontroller or ICs including flip-flops or similar devices that can "remember" and count. Reversing the motor is easy - a DPDT relay will do that - the rest is the challenge. You could mechanically toggle a DPDT switch but that is likely to be prone to failure.

Motor Required...

A stepper motor or servo will most likely be achievable, but what type of controller will you be using to execute your motion profiles? Let me know. You can also look up my company at www.Nyden.com...

Hiya Crunch,
This project of yours looks like a perfect time to get into pic's . For the end stops a micro switch at each end is all you need, this can trigger the pic to stop the motor and set it up for reverse. For travelling the five revoultions a magnet placed on the O.D. of one of the disc's and a hall effect sensor can be hooked up to a pic pin, then when 5 rev's have passed the pic can stop the motor and even return it to the home position. For powering the motor a simple H bridge would do the trick. All this can be done on a 16f628 and with a bit of thought it won't be hard to do.

Hope this Helps Bryan

When I first thought of these projects I thought that at least the first 2 would be very simple. #1 consisting of a few micro switches and the right wiring to make the motor move back and forth when the traveler reached the ends. I figured #2 would also be fairly simple. I knew #3 would be more difficult to do because of the motor only running 5 revolutions or for a certain amount of time. Boy was I wrong!!!!!!!
I am not opposed to using PIC’s at all. In fact I would really like to learn to use them because there are a lot of other projects I would like to do that they would probably be perfect for. Not being very familiar with them my questions are:
1. How much are the chips?
2. Are there many external parts to the circuits?
3. How much are the programmers?
4. How hard are they to program?
5. Can the chips be reprogrammed?
6. What kind of learning curve is there for all this?

Hey, I just got to thinking (what a concept!!!!) How do they get the door to open and close on a CD Rom drive? Isn't that kinda like the number 2 project I'm trying to do. How would that be wired up?
The other thing I found out today is that there are a couple of stepper motors at work that soomeone found that they might be throwing out. Looks like it's from SAIA and the part number is UBB1N05M10CNNA. Is this something I could use and what would the circuit look like to drive this thing?


Mike

crunch53 said:

Hey, I just got to thinking (what a concept!!!!) How do they get the door to open and close on a CD Rom drive? Isn't that kinda like the number 2 project I'm trying to do. How would that be wired up?
The other thing I found out today is that there are a couple of stepper motors at work that soomeone found that they might be throwing out. Looks like it's from SAIA and the part number is UBB1N05M10CNNA. Is this something I could use and what would the circuit look like to drive this thing?


Mike

Click to expand...

Mike, On the CD drives the door is opened mechanically (and shut) by the CD carrier, as it moves. The CD carrier is driven by a spindle which in turn is driven by a stepper motor.

Stepper motors are neat as you can drive them precisely, even doing part turns, but the motor by itself is useless. It needs a dedicated driver board which in turn needs a dedicated power supply. By that stage it gets complicated, some driver boards have on board programming for simple functions, some need a computer to supply the stepping sequences.

For your project an ordinary DC motor is quite sufficient. You control the (push button) FWD/REV action with a H-bridge (look it up) and you can control the 5 turn spec with micro switches as 5 turns would represent your 'traveller' having moved a certain distance. You could wire the micro switches to also control the H-bridge so the motor would move back and forth between the set limits until you stop it. If you want the back and forth bit occuring automatically a set number of times you need another micro switch (or optical switch) connected to a counter which resets the cycle after the set number had been done.

It all depends how much time and effort you are prepared to spend on this project....

Klaus

Klaus said:

Mike, On the CD drives the door is opened mechanically (and shut) by the CD carrier, as it moves. The CD carrier is driven by a spindle which in turn is driven by a stepper motor.

Click to expand...

All the CD-ROM drives, and CD Players, I've seen (which is a considerable number!) DON'T use a stepper motor, they use a simple DC motor fed from an H-Bridge (to reverse it), and a simple limit switch at either end. The latching and reversing action is controlled by a micro-controller.