Hi, new to the board.
I bought a kit to build a 2 axis cnc router/milling machine.
I don't want to build either one.
What I want to do is be able to turn the stepper motors on and off and vary the speed from zero rpm to hopefully 2,000 rpm. they have to be synchronized together. I don't care about the positioning of either motor.
I am told there is an Arduino controller I can get that will do this.
I am a tool and die maker, so stepper motors are new to me. I have been doing lots of reading and can't figure out if I can do this? Any help would be much appreciated.
What I am building, is a string serving machine for compound bows. I have built a manual serving machine, but it takes a long time to do the serving. if I can get two stepper motors sync'd, it could go much faster.
I attached a pic of what I have right now. Power supply not in the picture.
Very difficult to achieve, especially with a significant load. You will need low inductance, low resistance motors, a good motor driver and a high voltage motor power supply (typically much greater than 40 V).
jremington:
Very difficult to achieve, especially with a significant load. You will need low inductance, low resistance motors, a good motor driver and a high voltage motor power supply (typically much greater than 40 V).
I don't have to get to 2,000rpm
if it only got to 600 rpm, that would be ok
flopearedmule70:
What I am building, is a string serving machine for compound bows. I have built a manual serving machine, but it takes a long time to do the serving. if I can get two stepper motors sync'd, it could go much faster.
I attached a pic of what I have right now. Power supply not in the picture.
There is not picture, and one would be very useful. See this Image Guide. We don't know what you mean by "serving". In the programming world it usually means serving web pages when requested by a browser.
You say you need the motors to be synchronized but you also said "I don't care about the positioning of either motor". I don't understand the distinction you are making.
What is it that needs to be synchronized?
For the speeds you are talking about maybe simple DC motors with rotary encoders would be more suitable?
very sorry, I couldn't get the picture to work. I think my pictures are too big.
I will try to figure that out and post something.
Here is a link to a company that is making something similar.
They are programming the turns/steps so it stops automatic. I just want to flip a switch to control on and off and a potentiometer to control the speed.
By synchronized, I mean both motors have to start and stop at the same time. I don't care about the steps, because I would like to control that manually. I hope this helps. When I get home tonight, I will try to post a picture of how I do it right now.
Here is a link to someone doing it like I do it now.
Are you trying to wrap a covering thread around the bow strings?
And are the motors at each end supposed to rotate the bow strings without putting any twist in them - hence both motors must move at the same speed but in opposite directions?.
And while the strings are rotating you will feed the thread onto them?
Stepper motors do seem to be a convenient way of doing that.
Please post a link to the datasheet for the stepper motors you have and a link to the datsheet for your stepper motor drivers.
Are you trying to wrap a covering thread around the bow strings? YES
And are the motors at each end supposed to rotate the bow strings without putting any twist in them - hence both motors must move at the same speed but in opposite directions?. YES
And while the strings are rotating you will feed the thread onto them? YES
yes, yes and yes
thank you, you are better at explaining than I am.
I think, if you are using an Arduino there would be no need to use the little green circuit board. The Arduino should be able to control those stepper drivers directly.
I suggest you connect one motor and one stepper driver and then connect the Arduino to the driver and try the program in the link I gave you.
Thanks for your help Robin2. When I go to buy an Arduino...it's looks like there are more than one? Which one to buy?does it matter? Can they all do the same thing? If you tell me what one you recommend, I will buy it and then I can start playing with my project. I am new to stepper motors, this will be my first project involving electronics.
I was going to build a machine similar to a piano/guitar string winder, but this seems like more of a challenge and I can learn something new.
That looks like some serious kit. I think what you want to do is quite straightforward, but I would never have guessed what "serving" meant!
To get the motors synchronised, you can probably just a single step signal to both motors. If you are only serving, then you can hard wire them in opposite directions. The speed can be controlled by a potentiometer connected to an analog input on the Arduino.
According the spec of the controller (http://www.wantmotor.com/product/dq860ma.html), it has opto-couplers and can be powered by 5V, so I agree with Robin, you should be ok to connect directly to the Arduino without the green board (Breakout Board, aka BOB).
I think you need to handle acceleration though, because the system will have some significant inertia. If a motor stalls, it will mess things up. You can hear the acceleration ramp in the first Super Server video you posted.
flopearedmule70:
Is this all I need to buy for hardware?
Yes. But ...
There is no prohibition on anyone making a clone of an Arduino Uno but they may not use the Arduino Logo without permission and that board seems to have the logo and also seems to be too cheap to have permission to use it.
To get the motors synchronised, you can probably just a single step signal to both motors. If you are only serving, then you can hard wire them in opposite directions. The speed can be controlled by a potentiometer connected to an analog input on the Arduino
I am hoping I can change direction of one of the motors with a simple switch(don't know yet, but maybe a dpdt switch) so I can add twist to the string also. example: if the string is 40" long I will need 28 turns of twist in the string. I want to have a hand held with some switch's and potentiometer to hold on to while I'm running this thing.
According the spec of the controller (http://www.wantmotor.com/product/dq860ma.html), it has opto-couplers and can be powered by 5V, so I agree with Robin, you should be ok to connect directly to the Arduino without the green board (Breakout Board, aka BOB).
so I will need a separate 5v power supply plugged in? like a simple wall wort?
I think you need to handle acceleration though, because the system will have some significant inertia. If a motor stalls, it will mess things up. You can hear the acceleration ramp in the first Super Server video you posted.
I agree, I want to accelerate and decelerate. I can do this in the programming right?
There is no prohibition on anyone making a clone of an Arduino Uno but they may not use the Arduino Logo without permission and that board seems to have the logo and also seems to be too cheap to have permission to use it.
...R
Is this what I need? I get hung up on ebay too much sometimes.
flopearedmule70:
I am hoping I can change direction of one of the motors with a simple switch(don't know yet, but maybe a dpdt switch) so I can add twist to the string also. example: if the string is 40" long I will need 28 turns of twist in the string. I want to have a hand held with some switch's and potentiometer to hold on to while I'm running this thing.
Sure, a switch will work. e.g. one motor is always CW, the other can be switched CW/CCW.
so I will need a separate 5v power supply plugged in? like a simple wall wort?
You can tap off 5V from the Arduino.
I agree, I want to accelerate and decelerate. I can do this in the programming right?
flopearedmule70:
Is this what I need? I get hung up on ebay too much sometimes.
The two are probably identical technically. My recommendation is to buy a genuine Arduino to support the Arduino developers. But the decision is yours.
I am hoping I can change direction of one of the motors with a simple switch
That is perfectly possible. But the switch should tell the Arduino what direction is required and the Arduino program should control the motor. It would also be perfectly possible for the Arduino to get the motors to apply a certain number of turns.
Unless there is a strong reason for a more complex solution I suggest you use the Arduino Serial Monitor on your PC to give instructions to the Arduino about such things as direction, speed and number of turns.
Robin2:
Unless there is a strong reason for a more complex solution I suggest you use the Arduino Serial Monitor on your PC to give instructions to the Arduino about such things as direction, speed and number of turns.
You got that completely backwards, using a PC is clearly the more complex solution!
