Problems with Z axis steppers
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@yagodajm, what VIN are you using? (12V? 24V?). Also, what happens if you run the same experiment but with slower Z movement (e.g. 5 times slower)?
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I am running 12 V.
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@yagodajm, IIRC the dual Z plugs connect the steppers in series such that each has in average only 6 volts and once can affect the other. There is some discussion here https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors
Do you have the spec of the steppers you are using (inductance, resistance, etc)?
Try to run the experiment at lower speed, if the steppers will behave more reasonably it may be a voltage issue.
Another experiment is to connect just one motor at a time (install the two jumpers on the board for the other stepper), and see if it works as expected. Again, this will indicate a voltage issue.
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@zapta said in Problems with Z axis steppers:
you
OK, so if I install a 24 v power supply, that means I have to use a 24v hot end and bed,correct? I am thinking this is the way I need to go. -
This is the info on my steppers
Model: 42SHD0001-24 Step Angle: 1.8° Number Of Phase :2 Insulation Resistance : 100MΩmin.(500V DC) Insulation Class : Class B Rotor Inertia : 38g.cm^2 Mass : 0.2kg Rated Voltage : 12V Rated Current : 0.4A Resistance Per Phase : 30Ω±10% Inductance Per Phase: 37mH±20% Holding Torque : 260mN.m Detent Torque : 12mN.m
Can I put 24v tonthese ?
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@yagodajm said in Problems with Z axis steppers:
12V Rated Current : 0.4A Resistance Per Phase : 30Ω±10%
This stepper doesn't look as a good fit for 12V system with two steppers in series. You want a lower resistance and higher current stepper (ignore that voltage specification of the stepper, it doesn't matter).
Let's see if anybody here will come with a recommendation for a stepper.
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Until you get better steppers, you can try to connect second Z motor to E1 (and of corse config it properly), that way they are not connected in series at least.
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Do you have any recommended steppers to use with the duet maestro?
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Do either of these work? I am thinking the first one because of the current rating on the duet maestro.
Nema 17 stepper motor with step angle 1.8deg
Holding Torque: 45Ncm(63.74oz.in), 12-24 VDC
Rated Current/phase: 1.50A & Phase Resistance: 2.3ohms
Motor Type: Bipolar Stepper
- Step Angle: 1.8 deg.
- Holding Torque: 59Ncm(83.6oz.in)
- Rated Current/phase: 2.0A
- Phase Resistance: 1.4ohms
- Inductance: 3.0mH+/-20%(1KHz)
If I use these, do I still need to switch power supplies to 24 v ?
Thanks,
Justin -
@yagodajm, the spec of this 1.4OHM stepper looks much better. Let's see what they expert here say regarding 12V vs 24V.
There are stepper motor calculators. E.g. this one.
https://www.allaboutcircuits.com/tools/stepper-motor-calculator/
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@zapta
I am just worried with the current on the second one. The maestro Max's out at 1.6, I believe it is to much? -
Those motors would be a better fit. The rated current is ok for the maestro as you'd be using 70-85% of rated current.
24v is always better choice than 12v if possible, but keep in mind that requires 24v heater and fans (though fans you can use a buck converter to provide 12v).
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Everyone, thanks for all of your help, I went a head and ordered the
Motor Type: Bipolar Stepper
Step Angle: 1.8 deg.
Holding Torque: 59Ncm(83.6oz.in)
Rated Current/phase: 2.0A
Phase Resistance: 1.4ohms
Inductance: 3.0mH+/-20%(1KHz)At what ma should I run them at, around 1400ma?
thanks,
Justin -
1000 to 1400, but be sure to actively cool the board with a fan.
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Got it, thanks for all of you help.
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@yagodajm Partly Correct. It will be explained further down in this message.
The hotend part is a very easy part to replace. To save you some money, you can still use your 12V power supply to only power your 12V heatbed. That's until tou can get another heatbed that is 24V. Then again, some heatbeds are both 12V and 24V. It all depends on how you connect the heatbed. It will say that on the heatbed itself.
There is a way to use your 12V hotend with the 24V system. There is a command that will allow you to limit the amount of voltage to lets say, the hotend, the fans, the heatbed as well.
If you are interested with what I said above, just simple reply to my message.
Karma
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@Karma said in Problems with Z axis steppers:
There is a way to use your 12V hotend with the 24V system. There is a command that will allow you to limit the amount of voltage to lets say, the hotend, the fans, the heatbed as well.
Using PWM to "limit" the 24v power delivered to a 12v heater is not recommended. PWM means that it's just switching the power on and off very rapidly. So it's still getting 24v sent to a 12v heater, it's just off half the time. In a normal situation this can lead to premature heater failure. In a failure situation where full power is applied this is very dangerous. Not worth saving a few dollars.
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@Phaedrux What you said makes perfect sense sir. Please forgive me for doubting you.
This is something that person could use in a pinch, like for a very temporary amount of time.
I personally use the M106 S0.5 command just for my fans. I have a 24V system, I just couldn't find 24V noctua 40mm fan that was 24V. I really love these fans because they are almost silent when they are running. They are also very resilient when it comes to pushing out 24V to a 12V fan. That was when I was still learning the firmware and all. I was a Merlin guy at the start, then jumped to Repetier due to upgrading to a RADDS setup that didn't go anywhere for me. Always had problems with it.
I have a few DC Buck converters laying around here. I am not sure how they will respond to a variable input power. Like if they continue to try and push out 12V when there is only like 7V on the input side. I guess I have some homework to do.
Thanks for the lesson on this. I am very new to this firmware and the Duet3D 2 Wifi board. So far I love it. I wish I would have gotten the Duet3d 3 board. But I know my wife would kill me if I bought that right now.
