Rod Wrapping Machine

I want to use an Arduino and Stepper Motor to rotate fishing rod blanks as I secure the guides with thread. I want to be able to vary the speed using a pedal control that I will build using a Pot (similiar to a sewing machine foot control and similiar to several stepper motor examples I have found that use pots to control motor speed). I also want to be able to rotate the rod a specific number of degrees to assist in wrapping various decrative wraps. One additional thing I would like to do is disconnect the pedal controller and use a different pot to control the speed of rotation, this is so I can also use the wrapper as a rod dryer that must rotate at a slow rpm for up to 12 hours.

My plan is to bread board it first, then use a technique I read about where connection wires are wound around posts to make the connections to make the final production model.

The motor doesn't need to generate much torque, I don't have specific numbers but way less than a foot lb of torque. Max speed doesn't need to be high either, 1000 rpm motor would do the job if the rotation can be slowed to about 6 rpm.

Any suggestions or examples would be very much appreciated. Thanks in advance.

A step motor seems ideal for this task. Typical motors feature 200 steps per revolution (1.8 degrees per step) and can advance by any number of steps, or hold indefinitely at any of the 200 angular positions per revolution.

Step motors also can be programmed to rotate continuously at extremely low RPMs, up to a few hundred RPM.

You will need to measure the torque requirements from your rod holder and order a suitable motor.

You will need a matching step motor driver (Pololu has a good selection of modern current-limiting drivers) and a step motor power supply (typically 12 to 36V at a couple of Amperes).

Note: it would be a waste of your time to consider the cheap, extremely inefficient L293/L298 based motor drivers that you see advertised everywhere. Those old designs won't work well or at all with the majority of step motors.

Any Arduino is up to the task of controlling the system.

May I suggest you also make provision to emergency stop the rod rotation at any time. And decide if you need to hold that position or release the stepper so you can turn the rod by hand.

Paul

These links may help

Stepper Motor Basics
Simple Stepper Code

Several Things at a Time - the technique will be important if you want to be able to stop or change something part-way through.

Planning and Implementing a Program

...R

One additional thing I would like to do is disconnect the pedal controller and use a different pot to control the speed of rotation,

Changing the pot is not going to give you a different speed range. This is because a pot used in this situation is a ratiometric device. That means regardless of the pot's resistance it gives you a reading value between 0 and 1023 depending on how much the pot is turned.
You could always use a switch to change the speed of rotation into two ranges with a few simple lines of code.

Hi,
Is "decrative" decorative?. (Sorry for I am not a native english, and I'd like to follow the thread ...)
Thanks

vffgaston:
Is "decrative" decorative?. (Sorry for I am not a native english,

Ohhh the irony :slight_smile:

...R

vffgaston:
Hi,
Is "decrative" decorative?. (Sorry for I am not a native english, and I'd like to follow the thread ...)
Thanks

I suspect that it was intended to be - just a typo.

Interesting project - I don't recall any requests for this use case before.

It might make sense to have a second pot option so that that you don't have to constantly control the system with the sewing machine pedal - set it & forget it kind of thing. It would probably give you the drying facility too.

ov10fac:
My plan is to bread board it first, then use a technique I read about where connection wires are wound around posts to make the connections to make the final production model.

You mean like this?

Paul_KD7HB:
May I suggest you also make provision to emergency stop the rod rotation at any time. And decide if you need to hold that position or release the stepper so you can turn the rod by hand.

Paul

Thanks I forgot that requirement. When the motor is stopped, it must rotate freely so wraps can be positioned. Thank you for the good catch.

vffgaston:

ov10fac:
Thanks I forgot that requirement. When the motor is stopped, it must rotate freely so wraps can be positioned. Thank you for the good catch.

vffgaston:

A couple of years ago I redid my 18 year old coil winding machine to be run by a Nano. Had to do similar operations to what you are doing.

Do you have the foot control in hand so you can check the resistance and operation?

Paul

Paul_KD7HB:
A couple of years ago I redid my 18 year old coil winding machine to be run by a Nano. Had to do similar operations to what you are doing.

Do you have the foot control in hand so you can check the resistance and operation?

Paul

Paul,
No I will be building the foot controller. It will consist of a 10K Pot connected to a peddle/spring sort of thing that will allow me to rotate the pot fully by depressing the pedal, then when pressure is removed from the peddle the spring will return it to full up which will rotate the pot fully to the "off" position. This pot is what will be used to control the stepper speed similiar to this video.

jremington:
A step motor seems ideal for this task. Typical motors feature 200 steps per revolution (1.8 degrees per step) and can advance by any number of steps, or hold indefinitely at any of the 200 angular positions per revolution.

Step motors also can be programmed to rotate continuously at extremely low RPMs, up to a few hundred RPM.

You will need to measure the torque requirements from your rod holder and order a suitable motor.

You will need a matching step motor driver (Pololu has a good selection of modern current-limiting drivers) and a step motor power supply (typically 12 to 36V at a couple of Amperes).

Note: it would be a waste of your time to consider the cheap, extremely inefficient L293/L298 based motor drivers that you see advertised everywhere. Those old designs won't work well or at all with the majority of step motors.

Any Arduino is up to the task of controlling the system.

I checked out the controllers you suggested. I have a few steppers that only use 2-3 Volts. The min voltage of these controlles appears to be about 4.2 volts. So if my math is correct I need a 5 ohm resistor to drop 4.2V to 3.5V. Now where to find a 5 Ohm resistor?

I have a few steppers that only use 2-3 Volts.

No they don't. That is just the voltage required to give the maximum allowable current. You normally supply stepping motors with a much higher voltage and use a switching regulator to reduce this to the current you need. This over voltage allows the current to rise in the coils a lot quicker and therefore allows the motor to go much faster than otherwise.

So if my math is correct I need a 5 ohm resistor to drop 4.2V to 3.5V.

Maths is correct as far as it goes, you have neglected to factor in the voltage loss with what ever is going to switch the current. But as I said your reasoning is not correct. Get a proper stepping motor driver, one where you can adjust the current to the required level.

Grumpy_Mike:
Maths is correct as far as it goes, you have neglected to factor in the voltage loss with what ever is going to switch the current. But as I said your reasoning is not correct. Get a proper stepping motor driver, one where you can adjust the current to the required level.

Ok, so if the voltage and amp on the motor are 3.2 and 1 respectively, and the spec sheet doesn't provide any additional information, how do I choose the correct controller. I seem to be trying to make decisions on insufficient information. I am not familiar with electronics, I'm and Aero Engineer by education and Computer Consultant by trade, but my knowlege and experience with electronics is very limited.

Thanks for the guidance.

how do I choose the correct controller

For a 3.2V, 1 Amp/phase motor, you choose a step motor driver than can handle at least 1 Amp/winding, which includes most of the high quality, well supported drivers sold by Pololu.

The MP6500 is a good choice. Be sure to carefully follow instructions on wiring, with soldered joints and set the current limit correctly.

jremington:
For a 3.2V, 1 Amp/phase motor, you choose a step motor driver than can handle at least 1 Amp/winding, which includes most of the high quality, well supported drivers sold by Pololu.

The MP6500 is a good choice. Be sure to carefully follow instructions on wiring, with soldered joints and set the current limit correctly.

Thank you. The MP6500 was actually the one that I thought would work.

All the drivers on the linked page will work with a 1 Amp motor.

Ok,
Thanks to everyone. I have the motor a FH6-1726 (STP-58D215) and after a lot of digging I have found it to be a 24V Canon stepper motor from a Canon copy machine. I knew it was from a Canon copy machine because I removed it. I haven't found a complete spec sheet, but the ones I have found indicate it should work for my purposes.

I will start ordering parts. later next week, to include the controller. I have the Arduino already, a UNO, and a Nana. I will do the development on the UNO and use the Mini for final production.

I plan on using a button to control direction and to change the speed control from pedal to on-panel pot (two different buttons of course). I also need to think about how to program and wire a way to control the number of degrees to rotate. I may have to include an LCD readout and a button to change the number of degrees, and maybe even the number of rpm the motor is turning.

A lot of planning still needed, but should be a fun project.

I checked my box of hardward and found I already had a controller. I also found a DC motor with what I believe to be a tach sensor attached to the back of it. It looks interesting, and I will play with it a little when I complete this project.

Ok, So I have everything hooked up. I used the quick and dirty example found here.

With a few code mods I can run the motor forward and backward. I can run it for a specific number of revolutions etc.

Howver, I need to be able to slow the motor down. Right now its running pretty fast, I'd guess 100-200 rpm. I need to have the ability to slow it down to about 4-5 rpm. I tried changing the delay from 500 to higher values, but the motor stalled. I tried changing the current limit and again it stalled before I can get to the rpm I need. Then I used the code at the bottom which uses a potentiometer. Nope, still can't slow it down enough.

So, bottom line seems to be is the stepper a bad choice to get slow speed? Do I need to go to a gear motor and a motor speed controller to get the rpm I am looking for? Or is it a simple matter of varying the coil imput current to get the control I need? If that is the way to go, how do I control current?

Or, do I change the step resolution? If I reduce it 1/16th step, will I reduce the speed by 16?

Thanks