Manual motor movement and saving the steps

Dear all,

I would like to ask for ideas (will be even more happy with finished solution). I have a stepper driving a linear glide, belt type. Is it possible to move the glide by hand to different positions with different speeds and get values to file of how many steps were made and with what speeds? It would also be important to count time of the pauses between the movements.
So basically it would be like recording a macro on a computer so you can play it back later.

Thanks
John

It is a little late but who knows if somebody comes across this in a google search or something, so;

No. It is not possible.

You need an optical encoder, hall sensor or other type of rotary encoder. See: [en.wikipedia.org] (or a linear but that would change the setup)

This limitation - Not being able to get a feedback of steps moved - is one of the biggest limitations to stepper motors in 3d printers because it is not possible to read-out missed steps and recover those.

Yes it's possible, but you will only be able to count full steps of the motor, and it may be quite hard work to filter the signal generated by the motor (in hardware or software) to get accurate results. An optical encoder would be a more conventional solution.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

There is no standard way or approach to do this. It is not part of the stepper concept that there is any feedback (like there is on many other systems). There are no industrial components or approaches that can do this.

It is an interesting concept for a hack. I just tried to connect a stepper to my oscilloscope. To me it seems near impossible without calibration (or modelling of the stepper)

That is to say, you need the characteristic of the signal the stepper gives out so you can compare it to what you read and then if you know the speed and steps for that signal you have your info. Maybe you can do that calibration by connecting one stepper to another stepper and make some signal fit to varying speeds and steps

But even with calibration/modelling it seems very very difficult. The amplitude of the signal changes greatly dependent on speed and change in direction will be very hard to catch. Anything is possible but unless you are seriously skilled at signal treatment and don't mind paying a lot of money for a circuit that can analyse these then I think it is fair to say that it is not a viable approach.

I have uploaded a video of me turning a stepper here:

[goo.gl]