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Pulse generator for stepper motor

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  • Paul Alciatore
    replied
    All that is needed to operate most stepper drivers is two signals, one for direction and the other is a stream of pulses that provide one step per pulse. There are many ways of doing this, both mechanical (switches) and electronic.

    The most modern way would be with a PIC device like PICAXE or Arduino or Basic Stamp. These can be programed to provide those signals. Controls could be switches, thumbwheel switches, a pot, or a variety of other things.

    Another electronic approach would be a pulse generating circuit using a timer chip like the 555 and a pot for speed control. A switch for directional control and perhaps a switch with a single pulse circuit for jogging.

    Both of these approaches are dead simple and there is no reason why they should not operate properly and reliably.

    Another approach would be a rotary encoder with a tachometer output. This would provide the pulses and a switch would be for the direction.

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  • DICKEYBIRD
    replied
    Originally posted by macona View Post
    Just enter code though MDI for simple stuff, I can send commands pretty quickly like that and it beats manual crank turning. Or just set the feed and use the arrow keys.
    Yup, I do a lot of simple stuff that way and it works great. No rocket surgery needed. The head bashing comes when I have to do the little model airplane venturis with an internal elliptical curve and/or taper from both sides of the part that have to meet each other in the middle. Bore ID of .177" with a .160" carbide boring bar. Lotsa places for a tiny lapse in concentration to cause a crash. Not that that ever happened of course.

    However, it is a miraculous thing to watch when it runs right and well worth the time spent....I think.

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  • macona
    replied
    Originally posted by DICKEYBIRD View Post
    True that Ed. You left off CAM'ing, post-processing and multiple screams of "Why the *&@$*# did it do that!"
    Just enter code though MDI for simple stuff, I can send commands pretty quickly like that and it beats manual crank turning. Or just set the feed and use the arrow keys.

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  • DICKEYBIRD
    replied
    Originally posted by daGrouch View Post
    I am finding that I spend more time sitting at the computer playing with wizards or CAD'ing when I could have made 3 simple parts manually.
    True that Ed. You left off CAM'ing, post-processing and multiple screams of "Why the *&@$*# did it do that!"

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  • macona
    replied
    You could just run an encoder though one of these chips, it outputs step/dir from the encoder input. Put a nice weighted handle on the encoder and something to give it a bit of drag to make it smooth.

    http://www.usdigital.com/products/in...s/ics/LFLS7184

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  • daGrouch
    replied
    I have those running through Mach3 and they are great for rapids with my 2mm pith screws but I find turning those smoothly for a good finish just as hard as turning the hand wheels smoothly.

    The lathe has the typical 1 speed screw engagement for Z in one direction and I don't have change gears for it. I want to mimic that electrically in both directions on both axis' (axi?) so I am not running back and forth to the MDI.

    In my mind I would have a speed control and 2 switches (On/OFF and Direction) for each axis for simple turning and facing. A multi-pole switch for flipping between CNC and pulsers would be added at the input of the drivers.

    I am finding that I spend more time sitting at the computer playing with wizards or CAD'ing when I could have made 3 simple parts manually. Besides, my machine is not accurate enough to use CNC all the way so I have to stop and tweak too much.

    Ed
    Last edited by daGrouch; 06-15-2015, 09:19 AM. Reason: formatting

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  • MaxHeadRoom
    replied
    What you could use is a standard Step/dir drive and use a directly connected PWG or hand wheel, which is essentially a 100p/rev encoder.
    They come up on ebay quite frequently, the advantage is they have the tactile graduated indents.
    Max.

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  • daGrouch
    started a topic Pulse generator for stepper motor

    Pulse generator for stepper motor

    Howdy. I am looking for a confirmed working simple stepper pulser / speed control module that I can wire up to a driver. I bought one of the grey digital readout units on eBay and it was dismal . The other style (2 buttons + knob) would be fine but a post in another forum said they are bugged and only work in one direction. The import units are all copies of each other and I can't tell if any one seller has a fixed version. I wish eBay had item reviews like Amazon!

    I already have steppers on each axis and I want to have bi-directional powered lead screws for manual machining.

    Thanks,

    Ed
    Last edited by daGrouch; 06-15-2015, 06:24 AM.
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