Using a Duet 2 board with external stepper drivers
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@peter247 said in Using a Duet 2 board with external stepper drivers:
on point 3 , I would say you need a mosfet or use a ac heated bed ?
Looking at the docs it says 18 amp which is 435 watts max for a 1100 x 600 bed that is a bit low.I agree, you should plan for around 0.4W per sq cm of bed. A bed of that size needs an AC mains voltage bed heater controlled by a zero-crossing SSR.
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hello,
Thanks for answering. The MOFSET used for my heating bed will be redirected to another MOFSET with AC 10A on 240V, which is enough power to heat by bed.
The problem I had with my previous board (Ultratronics) is that my motors and stepper drivers were not activated by this board (signals did not move the motor). I already have big motors, controlled with D808 drivers. I want to use these drivers and have no need for the internal drivers, except for my extruder, which is a regular Nema17.I need 12V ports for my fans, but the Duet3 does not support the breakout board for my external stepper drivers so I can't use that one. How to make the fans 12V?
Does the initial configuration go by sd card or by usb?
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And @dc42 , there is a +5V input in the DCI, so why is there need for an additional breakbout board? Is that 5V not sufficient?
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@peterartechno said in Using a Duet 2 board with external stepper drivers:
And @dc42 , there is a +5V input in the DCI, so why is there need for an additional breakbout board? Is that 5V not sufficient?
The outputs on the expansion header and CONN_LCD only have 3.3v signals levels, so they are not safe to use with a 5V supply.
The usual way of driving 12V fans from a Duet 2 is to use a step-down converter to generate 12V and feed its output into the centre pin of the V_FAN jumper block.
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Ah I see I have 24V fans so that will not be a problem. When reading the page of the expansion breakout board, I read that the board will have a voltage of 3.6V. When I follow the instructions, it states that I have to put the STEP+ of my driver in the +5V of my servo connector (one of the two). But if I have more than 2 drivers, how do I set it up within the expansion board?
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You can connect multiple STEP+, DIR+ and ENA+ wires from your driver to the same +5V pin.
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How does it get the signals then? From all the - pins?
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@peterartechno said in Using a Duet 2 board with external stepper drivers:
How does it get the signals then? From all the - pins?
Yes, it's the difference in voltage between the + and - pins at the external driver input that the driver responds to.
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okay thanks, is there also a limit to how much pins you can connect to the 5V pin? I assume that there is a maximum of amperage that it can hold? I have 3 d808 leadshine stepper drivers.
Is it also possible to connect the E+, D+ and S+ within the driver and using one cable to get to the 5v?
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Each external driver input pin draws only about 10mA or less, so you can connect as many as necessary to each +5V pin.
If we ever revise the EBOB design, we'll likely add a +5V pin to each stepper driver output connector to make this type of wiring easier.
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Thanks for your answer. I found out that my driver also accepts 3.3V (tested with arduino mega). Is it possible to directly connect the 6 pins from the EBOB to the driver? No extra 3.3V pin
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@peterartechno said in Using a Duet 2 board with external stepper drivers:
Thanks for your answer. I found out that my driver also accepts 3.3V (tested with arduino mega). Is it possible to directly connect the 6 pins from the EBOB to the driver? No extra 3.3V pin
Yes.
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@peterartechno said in Using a Duet 2 board with external stepper drivers:
Is it also possible to connect the E+, D+ and S+ within the driver and using one cable to get to the 5v?
Yes, that too.
