break out board
14 Mar 2015 10:56 #56802
by thor44
break out board was created by thor44
I am almost finished with my cnc router and at the last minute I decided to add a 2nd lead screw to the x axis and I want to know if I can run both stepper drivers on one output from the break out board or do I have to have them on separate outputs?
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14 Mar 2015 18:35 #56807
by pippin88
Replied by pippin88 on topic break out board
thor,
It is possible to have two stepper drivers hooked up to the same breakout board output.
You can do the same thing in software (Hal).
Both these approaches mean that the two steppers will always move together and you can't home them separately.
Be careful when you do this, the steppers may turn in opposite directions - if so you need to reverse the wiring of one phase of the stepper.
More advanced is the use of gantrykins, which allows separate homing for squaring of the gantry, but it seems to have some issues and most people favour just tying the two steppers together physically or via software.
It is possible to have two stepper drivers hooked up to the same breakout board output.
You can do the same thing in software (Hal).
Both these approaches mean that the two steppers will always move together and you can't home them separately.
Be careful when you do this, the steppers may turn in opposite directions - if so you need to reverse the wiring of one phase of the stepper.
More advanced is the use of gantrykins, which allows separate homing for squaring of the gantry, but it seems to have some issues and most people favour just tying the two steppers together physically or via software.
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16 Mar 2015 09:27 #56882
by thor44
Replied by thor44 on topic break out board
so what do I have to do in HAL to use one output for two stepper drivers? And where do I find gantrykins? how do I use it?
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17 Mar 2015 16:22 #56927
by pippin88
Replied by pippin88 on topic break out board
If you are using the parallel port you just link the signal to two pins. You can see below I have Y step going to both pin-04 and pin-06, and Y Dir going to both pin 5 and pin 7.
If you are using Mesa hardware step generation then you need to add the second stepgen to pos-cmd:
So:becomes:(This sends the same position command to two stepgens.)
Have a look at the gantrykins manual (google gantrykins). Have a good read, but I suggest just starting with trivkins (the default kinematics)
net xstep => parport.0.pin-02-out
setp parport.0.pin-02-out-reset 1
net xdir => parport.0.pin-03-out
net ystep => parport.0.pin-04-out
setp parport.0.pin-04-out-reset 1
setp parport.0.pin-05-out-invert 1
net ydir => parport.0.pin-05-out
net ystep => parport.0.pin-06-out
setp parport.0.pin-06-out-reset 1
net ydir => parport.0.pin-07-out
net xstep => parport.0.pin-08-out
setp parport.0.pin-08-out-reset 1
net xdir => parport.0.pin-09-out
net spindle-cw => parport.0.pin-14-outIf you are using Mesa hardware step generation then you need to add the second stepgen to pos-cmd:
So:
axis.1.motor-pos-cmd => hm2_7i43.0.stepgen.01.position-cmdaxis.1.motor-pos-cmd => hm2_7i43.0.stepgen.01.position-cmd hm2_7i43.0.stepgen.02.position-cmdHave a look at the gantrykins manual (google gantrykins). Have a good read, but I suggest just starting with trivkins (the default kinematics)
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