Machsupport Forum
General CNC Chat => Show"N"Tell ( What you have made with your CNC machine.) => Topic started by: aero on September 19, 2013, 02:24:35 PM
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Hi ;D
i was trying to understand how can i drive my 3 axis steppers via usb??
i mean: as i red mach 3 sends via the parallel port 2 signals (step and dir) the step signal is made of a pulse that becomes high (1) for each step that should be done... and the dir signal made of a constant high(1) or low(0) level depending on the sense the stepper should turn (cw or ccw)..
however what can i use to make the steppers "understand" this signal??
i already heard about the solution of the l298+l297 but i prefer another type of solution
thank you
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You can get either a usb or ethernet smooth stepper and breakout board from cnc4pc.com. cost is about $400
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USB is all about data transfer and not about control & timing, you can't drive your steppers via USB as the timing to do this isn't available with USB as it is with PP, what you can do is send information detailing what you want the steppers to do to an external controller which deals with the timing to run the steppers, so as Bob has said you need to buy an external controller.
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I would prefer the ethernet as the usb only has one tx-rx channel. Electrons move at 186,000 miles per second and my processor operates at 3.7 mhz. How quickly do you want things to happen? The smooth stepper is an external controller if you will that emulates the PP signals. A PP is limited in the number of I/O's it can transmit and receive. The ethernet smooth stepper emulates 3 PP's simultaneously. It is also possible to run Mach3 on a 64bit machine using this card.
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Electrons move at 186,000 miles per second
I just want the Chronograph they used to clock that rascal. ;D
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Hey. It may be old but it is adequate for the CNC. I need to upgrade but I'm waiting for the deals after the holidays. My restriction is that I cannot run ANY other programs when the CNC is running.
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Electrons move at 186,000 miles per second
An electron can approach, but never quite reach, the speed of light in a vacuum. (http://home.web.cern.ch/about/accelerators/large-hadron-collider).
Tweakie.
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Forgive me for the rounding error. The figure is 186,282.4 statute miles per second. Or more precisely 299,792,458 meters per second. As long as I am exaggerating to make a point the least I could be is precise. Point taken.
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Tweakie, does this mean I wil have to revert back to mechanical fuel injection and ditch the EFI on the dragster to reach my goals?
Did they design the Hadron collider to accept a pod you could ride in? Seems a terrible waste if they didn't. ;D
Brett
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Did they design the Hadron collider to accept a pod you could ride in? Seems a terrible waste if they didn't.
That would be some ride Brett ;D
Tweakie.
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My Physics teacher used to include a question about the speed of electrons in wires to catch people out, the speed of the Signal is close to the speed of light but the actual speed of the electrons moving in a conductor due to an EMF and neglecting small random movements is actually very low.
In a 1mm diameter conductor carrying 1 amp the average speed of electrons measured over a 1cm length of the conductor is in single figure mm/min.
There's lots of 'em in there (something like 8.4*10^22 electrons/cm^3) and current is a measure of the volume of electrons moving through the conductor,
- Nick