Stepper VS DC motors

[kayakerca]

Is there any drawback to PWM controlled DC motors?
I know that one of the issues with stepper motors in the lack of feedback.

I am not experienced with the PWM controlled DC motors. You are correct about the lack of feedback with the stepper motors, but it's probably not a significant issue in a coil winder environment. With the stepper, you tell it the exact number of steps to take, it takes them and then it stops and stays there in that exact spot until you tell it to do something else. A stepper doesn't just randomly cruise to a stop as the rpm's wind down, it stops at the exact spot it is supposed to. All that to say that you know exactly where it is when it stops moving. I initially thought the lack of feedback would be an issue too, but that was before I came to grips with exactly what that stepper was doing. As I was saying, I am unfamiliar with PWM controlled DC motors, but I am guessing that either route will get you where you want to be just fine.

[Lyrebird Steve]

It is a whole lot easier, circuit wise, to build a pmw/ dc motor setup.

Stepper motors, while being fantastic where accuracy is concerned, can be a bit of a bother when tasked with variable rpm designs.

The newer controller boards from Phidgets allow for RPM setting and have an Acceleration/Deceleration setting so it ramps up to speed and down again when it's about to finish. Nice feature

[David King]

With most steppers and stepper drivers you still have the "midband resonance" issues where the motor can stall and freeze even under small torque demands. I think things are getting better but you get what you pay for.

No reason not to add a digital counter for feedback if you want to know your exact turns. If you aren't ever losing steps -well then you can take it off and move it to another project.

[kayakerca]

With most steppers and stepper drivers you still have the "midband resonance" issues where the motor can stall and freeze even under small torque demands. I think things are getting better but you get what you pay for.

I've been winding on bipolar steppers for both traverser and winder for about a year now and have never had either stall or freeze. I understand from people that know a lot about steppers that they do not like to operate around their resonant frequency, but at the speeds I wind at, I have never had an issue. Same applies for the bipolar stepper (linear actuator) I use for the traverser. Now I have only wound ~ 120 coils, but I have never had them lock up or freeze on me. That said, I have had the traverser derail (as I like to refer to it as), but I think I finally figured out that that was a result of my poor coding skills rather than the fault of the stepper or controller. After changing a couple of aspects of the execution of the coding, I have not had a problem.

On the more ZEN side of things, in the past 2 or 3 years handing out here, I have come to believe that every type of winder can produce top quality pickups. I also believe that the style of winder a person uses only reflects the way a person wants to wind pickups. . . Their personal view of winding "mojo". I don't think it matters if they want to us an egg beater, a drill, a sewing machine, a PWM controlled DC motor or stepper based winder. If they want to produce some outstanding pickups, they will and they will come to it by buying or building a winder that they feel gives them their mojo. In my late night Friday opinion anyway.

[Jazz P Bass]

Yeah, stepper motors are great if you can handle the step coding.

The available torque is greatest at slow speeds.

[David Schwab]

Neither am I. What I do is to copy the post onto the clipboard before posting. If the post fails to take, the text is still on the clipboard, ready for a 2nd try.

I do the same thing. When I remember.