Stepper driver and Stepper shield

aldenhart
Posts: 132
Joined: Tue Apr 10, 2012 2:17 pm

Re: Stepper driver and Stepper shield

Post by aldenhart » Tue Apr 10, 2012 5:28 pm

Thanks. I heard the comment. We are continuing to work on new designs and enhancements and will keep this in mind.

A Question for the group - would there be interest in a TI mounted on a carrier board similar to the Pololu driver?

Another question - is there interest in going above 2.5 amps with a different driver solution? Realize that this would be more expensive. By way of comparison the Geckodrive G250x is 3.5 amps and $81 each in singles.

Thanks for your answers

Alden

Enraged
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Joined: Mon Apr 09, 2012 8:29 pm

Re: Stepper driver and Stepper shield

Post by Enraged » Tue Apr 10, 2012 7:39 pm

If you could make a Pololu-compatible plug in replacement with the better stepper driver, I would buy them when I upgrade my motors.

nogthree
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Location: Brisbane, Australia
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Re: Stepper driver and Stepper shield

Post by nogthree » Tue Apr 10, 2012 9:28 pm

If you can throw in limit switch support I'll switch to whichever has it. Right now running a GRBLshield and limit switches are a major concern for me.
- Brendan Halliday.
ShapeOko Wiki Userpage

aldenhart
Posts: 132
Joined: Tue Apr 10, 2012 2:17 pm

Re: Stepper driver and Stepper shield

Post by aldenhart » Wed Apr 11, 2012 1:01 am

There is nothing in the current grblshield that prevents using limit switches. All unused digital and analog pins are brought out to connectors on the board. What you would need to do is put a male or female 0.100 header on the board and wire to them. Take a look at the picture at the top of this topic and you'll see what I mean.

nogthree
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Re: Stepper driver and Stepper shield

Post by nogthree » Wed Apr 11, 2012 1:56 am

aldenhart wrote:There is nothing in the current grblshield that prevents using limit switches. All unused digital and analog pins are brought out to connectors on the board. What you would need to do is put a male or female 0.100 header on the board and wire to them. Take a look at the picture at the top of this topic and you'll see what I mean.
Whoops, sorry. I wasn't aware it was using I/O pins to for limit switching etc. I know there was talk about changing the pinout at some point though, is the info on the wiki about this likely to change any time soon?
- Brendan Halliday.
ShapeOko Wiki Userpage

aldenhart
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Re: Stepper driver and Stepper shield

Post by aldenhart » Wed Apr 11, 2012 2:21 am

There has been a discussion on the grbl github about how best to use the pins that are not already dedicated to the XYZ step and direction and the enable line. There is a general understanding of what pins to use, but the release of grbl that will support homing and limits is still in development. Whatever it shakes out to be, all the pins that are needed are accessible.

nogthree
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Re: Stepper driver and Stepper shield

Post by nogthree » Wed Apr 11, 2012 2:40 am

aldenhart wrote:There has been a discussion on the grbl github about how best to use the pins that are not already dedicated to the XYZ step and direction and the enable line. There is a general understanding of what pins to use, but the release of grbl that will support homing and limits is still in development. Whatever it shakes out to be, all the pins that are needed are accessible.
Thanks for the clarification Alden, it's much appreciated :)
- Brendan Halliday.
ShapeOko Wiki Userpage

roberlin
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Location: Baton Rouge, Louisiana

Re: Stepper driver and Stepper shield

Post by roberlin » Wed Apr 11, 2012 12:56 pm

I also like the idea of the pololu compatible ti-driver board.

Something else that might be cool is if there was a grblshield 3d printing upgrade board containing the 4th driver and other necessary components. These could be on a separate shield that is sandwiched between the arduino and the grblshield (I have no idea if this is practical). This would allow one to upgrade the electronics parallel to the shapeoko.

RedOko
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Location: TX

Re: Stepper driver and Stepper shield

Post by RedOko » Wed Apr 11, 2012 2:00 pm

If I'm looking at it right, and Alden please correct me if i'm wrong

the current grblshield does not have the 4th driver and the arduino Uno is not capable of running the current programs for 3D printing. I don't know about TinyG, it has the 4th driver for the extruder but I don't know if its capable of running the common available software for 3D printing.

If you have the Pololus, you can invest in a Mega and RAMPS and an extruder to make it capable of 3d printing. I'm going with the
Azteeg for my 3d printer since I already have the Pololus.
Luis
aka "RedOko"

aldenhart
Posts: 132
Joined: Tue Apr 10, 2012 2:17 pm

Re: Stepper driver and Stepper shield

Post by aldenhart » Wed Apr 11, 2012 2:46 pm

That pretty much sums it up. At this point most of the 3d printer stuff runs on something other than the Uno/Decimillenova (I always spell that wrong - you know what I mean), like the Arduino Mega or something else altogether. There are a lot of 3d printing firmwares out there and I think some will run on the Atmega328p - family machines and some won't, but I don't know this area well enough to comment.

The RAMPS board and the other RepRap electronics are specifically designed for this and have electronics for extruder motors, extruder heating, heated build platforms and other things. Some of the heated build platforms take a LOT of current, by the way, so that ups the complexity of the board. Some to the earlier generation Makerbot stuff did run off the Uno or similar ATmega328p platforms but they communicated off-board for extruder and other controls.

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