Hi, I am new to the Arduino world, I am a hobby machinist with a small work shop
What I am trying to do is make a computer controlled Indexing head for cutting gears
I will want it to be able plot any point in a 360' circle so I can produce any gear wheel from 12 - 120 teeth (at the moment I use a manual indexing head)
I have found a unit with a 2-phase 57 stepper motor, and would like to know if this is a suitable choice
Thanks in advance for any help
Bob
If you need to use a microprocessor, then yes, Arduino could be suitable, it is a microprocessor. There is nothing unique about Arduino that would make it unsuitable to my knowledge. There is nothing unique about Arduino that would make it more suitable than any other microprocessor that I am aware of.
But that's about as much advice as I can give without more information, based on what little of your description I was able to understand.
You mentioned "indexing any point" and "plotting any point" but it's not clear to me what this actually involves. Moving a stepper motor to a given angle? On a screen?
Please post a link to the specs of this "unit".
You will probably need some form of shaft encoder to know the position of the gear to be made ( the indexing table ) . That would feed a signal to your micro , on which you can then act .
Indexing it automatically is not so easy and may require a motor with a lot of torque and accuracy ..
I would investigate how it is done on NC machines for inspiration .
Not a beginner project !!
It’s more of a mechanical design issue to start with .
Thank you for your reply's
What I need the stepper motor to do is just to rotate a chuck to any given angle in steeps of how ever many teeth I want to make a gear in
for example: if I wanted to make a 37 tooth gear I would need to be able to program the Arduino to tell the the stepper motor via the driver board to move 37 even spaced increments so that I would end up with a gear with exact evenly spaced teeth, I know all the mechanical aspects of cutting gears I just want to make my life easier and learn a new skill, plus the enjoyment of building a new bit of workshop kit
A few more bits of info on the motor I am looking at:
2-phase 57 stepper
Drive ratio: 6-1
Step angle: 0.3 degree/step
Regards Bob
What is the machine having the chuck on it?
I've built a position control using a rotating table, stepper, driver, power supply, an Arduino UNO connected to a Pc. From the Pc the funtion of the UNO is set to either steps per revolution or angle per step. A step fwd and a step bwd button is the used to run the table.
The rotating table sits on the table of a mini mill.
So, your motor has 1200 steps per revolution, 1200 / 37 = 32.4324324324 steps. You can't make 0.4324324324 steps, that's the problem with stepper motors.
Please try to take a photo of the ratings plate of the motor, it should show an actual model number, etc., and post it here.
You may get something out of this thread
a7
One problem is what happens if the stepper motor misses the odd step Which they easily can if the inertia of the load is high . I guess you need to build something to try out the positioning .
IMO You really need to know the position of the chuck with an encoder .
As I said how is it done with NC machines ??
Unless you are cutting gears all the time , this is a big project .m
There are lots of unknowns...
The Arduino can't directly drive a stepper motor. It can't put-out enough current, and probably not enough voltage for a motor big enough for your needs.
You will need a driver circuit/module (if that's not already built-into the motor assembly) and you need to know what kind of signals/data it wants from the microcontroller.
In the hobby world, the "steps" are sent to the driver as 5V pulses and basically any stepper motor and driver will work with the Arduino and the associated software libraries.
0.3 degrees doesn't "feel" precise enough to me but if you are a machinist you probably have a better feel for that than me. I'm sure steppers in NC machines are geared-down for more precision, but you need to minimize play and backlash and I don't know it that's accomplished simply by using precision gears, or what...
There is also micro-stepping which allows the motor to move a fraction of a step but I don't know how much actual accuracy/resolution you get from that.
That makes sense. Most steppers are 200 steps per revolution = 1.8 degrees per step. But I'd guess that most milling machines have additional gearing-down.
It has already been done some 10 -15 years ago and is still current.
Look on one of the model machining sites (UK) on Google.
DOESN'T work that way, Your stepper will still have to crank the handle on your indexer to make the appropriate movement. That is the best you can expect!
Hi Paul
Thanks for your reply,
My stepper motor is connected to a chuck and mounted on my milling machine
I have all the mechanics in place, its just the programming that I was concerned with, I just wanted to know is it
posable to get the Arduino to tell the driver board to step the motor for example: 27 evenly spaced points of a circle one step at a time so that I can manually cut a tooth then push a programmed button to move on one step and so on
I would like to be able to cut gears from 12 teeth to 120 teeth
Thanks Bob
No it is definitely NOT! Machines that can do that use servos and controllers that can turn the servo in one ten thousands of a degree or less.
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