RAMPS has a huge number of spare pins to work with, its ideal for this kind of further development.
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Re: Adding another stepper motor
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Is this motor a good investment?
Hi,
I did try to recycle used motors not taking too seriously the resistance (4.7 ohms per coil) and just connected them to my 4988 drivers using 12V. The result is burning hot motors that after a few minutes start skipping steps.
After looking around on Ebay, I saw these Nema 17, 70 oz-in torque, 30 ohms per coil and 0.4A@12V motors for around $16 USD/ each. The questions are: are they good motors? Will they still get hot and skip steps?
Any advice will be greatly appreciated.
[cgi.ebay.com]
FYI - I have a prusa mendel with linear bearings, wade's extruder and Budasnozzle 1.2 hot end.
I did try to recycle used motors not taking too seriously the resistance (4.7 ohms per coil) and just connected them to my 4988 drivers using 12V. The result is burning hot motors that after a few minutes start skipping steps.
After looking around on Ebay, I saw these Nema 17, 70 oz-in torque, 30 ohms per coil and 0.4A@12V motors for around $16 USD/ each. The questions are: are they good motors? Will they still get hot and skip steps?
Any advice will be greatly appreciated.
[cgi.ebay.com]
FYI - I have a prusa mendel with linear bearings, wade's extruder and Budasnozzle 1.2 hot end.
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Re: Is this motor a good investment?
no the inductance is too high they may be torquey but they wont be able to spin very fast. look for something with less than 10mh of inductance.
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Re: Adding another stepper motor
Andrew Smith Wrote:
-------------------------------------------------------
> RAMPS has a huge number of spare pins to work
> with, its ideal for this kind of further
> development.
so has anyone done this or does anyone have a tutorial, ive got an extra driver that id like to hook up a 3rd extruder to.
-------------------------------------------------------
> RAMPS has a huge number of spare pins to work
> with, its ideal for this kind of further
> development.
so has anyone done this or does anyone have a tutorial, ive got an extra driver that id like to hook up a 3rd extruder to.
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Re: Is this motor a good investment?
Thank you for the response. Any recommendation?
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Re: Is this motor a good investment?
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Threaded Rod NEMA 17
Threaded Rod NEMA17 or Threaded Shaft Nema 17 are languages from 3Ders or not, I am not sure is not that important.
But let's figure out what's in professional:
Threaded Rod or Threaded Shaft Stepper Motor could be External Drive Linear Stepper Motor or Non-captive Linear Stepper Motor.
3Ders can find NEMA17 Threaded Rod Stepper Motors are used in a Makerbot or Reprap.
Tr8*8 150mm or 280mm long Leadscrew are talked the most for 3d printer Z axis. Compared with combination: NEMA 17 Stepper Motor, Coupler and Metric Screw, a Threaded Shaft Nema 17 are much better in quality. The results of the printing is different in night and day.
You could read more the following link:
Z Motor setup comparison
Metric Screw is material in 45# carbon steel usually. But a Threaded Rod from LoopMotion.com is #304 stainless steel.
How Much a Threaded Shaft Nema 17 Stepper Motor?
How much costs a threaded rod nema17, it's mainly depend on the Length of the Leadscrew, the Diameter, the pitch etc.
A nema17 threaded shaft stepper motor with 280mm Tr8*8 leadscrew and POM nut, sample price costs 30USD/pc.
Tr8*8 is not the only choice of Leadscrew for 3d printer. But Tr8*8 is strong enough for any projects using a threaded rod nema17.
But let's figure out what's in professional:
Threaded Rod or Threaded Shaft Stepper Motor could be External Drive Linear Stepper Motor or Non-captive Linear Stepper Motor.
3Ders can find NEMA17 Threaded Rod Stepper Motors are used in a Makerbot or Reprap.
Tr8*8 150mm or 280mm long Leadscrew are talked the most for 3d printer Z axis. Compared with combination: NEMA 17 Stepper Motor, Coupler and Metric Screw, a Threaded Shaft Nema 17 are much better in quality. The results of the printing is different in night and day.
You could read more the following link:
Z Motor setup comparison
Metric Screw is material in 45# carbon steel usually. But a Threaded Rod from LoopMotion.com is #304 stainless steel.
How Much a Threaded Shaft Nema 17 Stepper Motor?
How much costs a threaded rod nema17, it's mainly depend on the Length of the Leadscrew, the Diameter, the pitch etc.
A nema17 threaded shaft stepper motor with 280mm Tr8*8 leadscrew and POM nut, sample price costs 30USD/pc.
Tr8*8 is not the only choice of Leadscrew for 3d printer. But Tr8*8 is strong enough for any projects using a threaded rod nema17.
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Trouble with stepper motors
I am having trouble getting my stepper motors to move, they simply hum when pots on driver is turned towards the minimum and click and lock when the current is turned up.
I am using ramps 1.4 (reprap discount) and standard 4 wire NEMA 17 stepper motors, I only have motors plugged into the ramps at the moment.
I have loaded Marlin but also tried sprinter
I have checked and double checked that wiring is correct (identified coil pair).
Pronterface seems to be working fine as I can connect, and get the motors to make some noise.
The only way the motors will show any sign of doing anything (locking, humming) is when i click the home button, the jog command does not seem to do anything.
Could it be an issue with power supply not providing enough current? I am using a ATX and have checked the voltage.
Or is it an issue with the configuration?
I also tried the mechanical switch in case this was causing the problem, but this did not seem to change anything.
I am a little lost as to what to try next, any help would be appreciated!!
I am using ramps 1.4 (reprap discount) and standard 4 wire NEMA 17 stepper motors, I only have motors plugged into the ramps at the moment.
I have loaded Marlin but also tried sprinter
I have checked and double checked that wiring is correct (identified coil pair).
Pronterface seems to be working fine as I can connect, and get the motors to make some noise.
The only way the motors will show any sign of doing anything (locking, humming) is when i click the home button, the jog command does not seem to do anything.
Could it be an issue with power supply not providing enough current? I am using a ATX and have checked the voltage.
Or is it an issue with the configuration?
I also tried the mechanical switch in case this was causing the problem, but this did not seem to change anything.
I am a little lost as to what to try next, any help would be appreciated!!
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Re: Trouble with stepper motors
... re-check correct pin assignment and clock speeds - 'humming' is either not enough current or too high stepping rates ...
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Re: Trouble with stepper motors
Problem solved!!
Seems like both the firmwares i tried were sending the motor a signal they didn't like, i tried the ramps14 test code and it worked so i tried the official version of marlin and they all seem to be working fine!
Seems like both the firmwares i tried were sending the motor a signal they didn't like, i tried the ramps14 test code and it worked so i tried the official version of marlin and they all seem to be working fine!
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Re: Is this motor a good investment?
those have too many amps, they should be between 0.5 and 1.5, sorry for the delayed response. although qu-bd cannot make a decent hot end, they do have very good motors, [store.qu-bd.com]. they are out of stock, but they are fairly good. also you may want to try adjusting the stepper drivers, you probably have them set too high.
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Lower Voltage But Louder Motors?
I've been using a set of Shinano Kenshi STP-42D3018 stepper motors for the X, Y, and E motors in my RepStrap that are 8.8V 0.64A 11.6Ω bipolar and 5.2V 0.9A 5.8Ω unipolar. I've been using them as unipolar motors because the bipolar resistance of 11.6 Ohms is apparently too high. They've actually worked quite well, especially the XY, with 47 oz.in. of holding torque. But it seemed like a waste to use these bipolar motors as unipolar. With so many different voltage ratings for stepper motors it also seemed like a waste to use 5.2V if there are motors using 3V and under. Plus the extruder motor was getting pretty warm; so if nothing else I wanted a stronger bipolar motor for that.
So I found a new set of motors that seem more ideally suited, especially for the E motor. These KL17H247-168-4B motors are bipolar with 62 oz in. torque. They use 2.8V at 1.68A 1.65Ω, which is a bit less current than 5.2V 0.9A 5.8Ω (or is it?). I installed one as my E motor and it works great, barely gets warm after hours of printing.
So I just installed one of these as the Y motor and tuned the stepper driver to the point where the motor has a reasonable amount of torque. But a couple of things are apparent right away. First, it seems to need me to dial up more current from the stepper driver than the 5.2V unipolar motor did. So that's interesting. And the motor is significantly louder than the previous motor, to the point where I'm thinking of going back to the old motor even though it's got a slightly higher power rating and gets a little warmer.
So I have a couple of questions...
So I found a new set of motors that seem more ideally suited, especially for the E motor. These KL17H247-168-4B motors are bipolar with 62 oz in. torque. They use 2.8V at 1.68A 1.65Ω, which is a bit less current than 5.2V 0.9A 5.8Ω (or is it?). I installed one as my E motor and it works great, barely gets warm after hours of printing.
So I just installed one of these as the Y motor and tuned the stepper driver to the point where the motor has a reasonable amount of torque. But a couple of things are apparent right away. First, it seems to need me to dial up more current from the stepper driver than the 5.2V unipolar motor did. So that's interesting. And the motor is significantly louder than the previous motor, to the point where I'm thinking of going back to the old motor even though it's got a slightly higher power rating and gets a little warmer.
So I have a couple of questions...
- Is loudness the result of a combination of factors that are hard to gauge? Bipolar motors are supposed to have more torque at lower speeds. Does this extra power come with additional vibration as a consequence? Are bipolar motors just generally louder?
Unipolar motors are supposed to be better for high speed. Am I better off having unipolar motors in my XY anyway, where torque is less important than speed?
When it comes to stepper motor current, sure I can run three 5.2V / 5.8A stepper motors and the printer will be a little more quiet, but am I wasting energy?
What values matter when considering compatibility with RepRap electronics? In stepper motor spec sheets they give helpful values like Driver Vref (2.4V), Inductance/Phase (2.4mH), voltage of course, and Current/Phase (0.9A). How do these values relate to the voltage and signals that stepper drivers are sending out?
As a buyer of stepper motors, how can I know ahead of time whether motors might be loud? Are certain voltage ranges louder than others? Are bipolar motors going to have more vibration than unipolar motors?
How can we reduce the loudness of stepper motors? Hanging the printer from the ceiling helps! But short of total isolation, and within the typical RepRap power range, how is motor noise best kept down?
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Re: Lower Voltage But Louder Motors?
The loudness of the motor mainly comes from the fact that current through coil is turned on and off in frequencies bellow 30 kiloHertz. The sound mainly goes away when microstepping as this frequency increases over audible range.
The 12v or 5.2v or 2.8v that is written on the motor has nothing to do with what voltage you run it through. You actually need to run the motor at several times more that voltage, e.g. most ppls on cnczone will advice x10 times that value. The ratings on the motor have more to do with ohms law and overall power-watts rating of the motor than it has to do with actual application you want it in.
For example since reprap uses 12V psu, there is no chance you can put 1amp of current through a coil with 40 ohms resistance, because simply ohms law says it would take max 0.3A. In practice that shouldnt be peaked value as the driver needs to switch much more before that happens, so its fast enough, because the 0.3A peak takes a lot of time to hit as the waveform is curving down - almost flat. Also generally speaking high coil resistance means thin wire and more windings, so generally higher inductance, thats at least one of the reasons ppls warn against higher inductance with voltages like 12v. Perhaps another is that high inductance has a harder time increase or collapse its field in a current reversal bipolar motor, so perhaps this ppls dont say just "coil resistance" but more generally "higher inductance" which somehow includes both.
To run a motor 5.2v / 5.8A that means a max 0.9 ohms (ohms law) but again thats practically much less coil resistance, probably again an ideal peak would be much xxlog times lower than that, and thats kinda impossible.
To actually check out ratings of a motor, they usually give 2 of three by ohms law and you can figure out whats missing: e.g. they give either current and coil resistance, or voltage and current, etc. This voltage should be much lower, several times lower than what you plan to actually use. This is about the same thing to say that the ohm's law max current is many times much higher than the peak point where stepper driver will turn off or reverse the coils.
The 12v or 5.2v or 2.8v that is written on the motor has nothing to do with what voltage you run it through. You actually need to run the motor at several times more that voltage, e.g. most ppls on cnczone will advice x10 times that value. The ratings on the motor have more to do with ohms law and overall power-watts rating of the motor than it has to do with actual application you want it in.
For example since reprap uses 12V psu, there is no chance you can put 1amp of current through a coil with 40 ohms resistance, because simply ohms law says it would take max 0.3A. In practice that shouldnt be peaked value as the driver needs to switch much more before that happens, so its fast enough, because the 0.3A peak takes a lot of time to hit as the waveform is curving down - almost flat. Also generally speaking high coil resistance means thin wire and more windings, so generally higher inductance, thats at least one of the reasons ppls warn against higher inductance with voltages like 12v. Perhaps another is that high inductance has a harder time increase or collapse its field in a current reversal bipolar motor, so perhaps this ppls dont say just "coil resistance" but more generally "higher inductance" which somehow includes both.
To run a motor 5.2v / 5.8A that means a max 0.9 ohms (ohms law) but again thats practically much less coil resistance, probably again an ideal peak would be much xxlog times lower than that, and thats kinda impossible.
To actually check out ratings of a motor, they usually give 2 of three by ohms law and you can figure out whats missing: e.g. they give either current and coil resistance, or voltage and current, etc. This voltage should be much lower, several times lower than what you plan to actually use. This is about the same thing to say that the ohm's law max current is many times much higher than the peak point where stepper driver will turn off or reverse the coils.
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Re: Lower Voltage But Louder Motors?
Practically take this as general reference, the images at the right side, (ignore the axis labeling and everything else, just pictures).
[en.wikipedia.org]
Thats somewhat a generic waveform or rising/falling edge. The ohms law give the end (top) value, but in practice notice that it takes a huge time to actually get at that. The driver needs to be fast. So the stepper driver needs to work with its own peak value where it interrupts stuff, and that needs to be in the left side, where the waveform is rising rapidly. In that area it rises rapidly, and it allows the driver to work at high frequencies with full current value. The more operating point is to the left, the fastest operation can be.
In practice that peak can be adjusted withing driver's limits, and depending on the driver and its settings it may or may not reach that peak value either (different driver's business). But at least thats what i think of the frame reference on motor picking, and what the parameters should point at.
[en.wikipedia.org]
Thats somewhat a generic waveform or rising/falling edge. The ohms law give the end (top) value, but in practice notice that it takes a huge time to actually get at that. The driver needs to be fast. So the stepper driver needs to work with its own peak value where it interrupts stuff, and that needs to be in the left side, where the waveform is rising rapidly. In that area it rises rapidly, and it allows the driver to work at high frequencies with full current value. The more operating point is to the left, the fastest operation can be.
In practice that peak can be adjusted withing driver's limits, and depending on the driver and its settings it may or may not reach that peak value either (different driver's business). But at least thats what i think of the frame reference on motor picking, and what the parameters should point at.
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Re: Lower Voltage But Louder Motors?
It's possible I haven't been getting great micro-stepping and this is adding to the vibration. The G3D stepper drivers that I use include a voltage pot and also a separate 30K trimpot, described this way: "turned fully counterclockwise pulls the ROSC pin to ground, turning it clockwise lets you to choose a reference. By pulling the ROSC pin to ground, mixed decay is set to be active 100% of the time, for both rising and falling currents, and prevents missed steps. If this is not an issue, it is recommended that automatically-selected mixed decay be used, because it will produce reduced ripple currents. Refer to the Fixed Off-Time section for details."
I found that the full counterclockwise position was giving too much vibration. I was able to reduce the vibration a little by setting it about 180° clockwise. The E motor still hums a bit, so I'll probably tweak that also. Neither motor is as quiet as my previous set-as-unipolar motors, but they're reasonable. Still, I might revert to the old motor on the Y axis since there doesn't seem to be any added value with this new motor.
Are there common stepper motors out there that have a good torque range and micro-stepping but just aren't very well suited to RepRaps because of their electrical characteristics? Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range. Should I favor the old motors on the basis that they're (a) quieter, (b) require less current, and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
I found that the full counterclockwise position was giving too much vibration. I was able to reduce the vibration a little by setting it about 180° clockwise. The E motor still hums a bit, so I'll probably tweak that also. Neither motor is as quiet as my previous set-as-unipolar motors, but they're reasonable. Still, I might revert to the old motor on the Y axis since there doesn't seem to be any added value with this new motor.
Are there common stepper motors out there that have a good torque range and micro-stepping but just aren't very well suited to RepRaps because of their electrical characteristics? Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range. Should I favor the old motors on the basis that they're (a) quieter, (b) require less current, and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
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Is it worth buy and use this motor?
Hi,
I found this motor )NEMA 17 42BYGH47-401A CNC Stepper Motor 62oz-in 1.68A) and it looks like that fits for assembling a 3d printer so...
Do you think this model works good for the a 3d printer? (RepRap Prusa Mendel 3D printer)
Is it worth buy it?
US$: 19.52
Model: 42BYGH47-401A
Step angle:1.8°
Motor length: 47mm
Rated voltage: 2.8V
Rated current: 1.68A
Phase resistance: 1.68Ω
Phase inductance: 2.8mH
Holding torque: 62Oz-in/4400gf.cm
Lead wire: 4
Rotor inertia: 68
I found this motor )NEMA 17 42BYGH47-401A CNC Stepper Motor 62oz-in 1.68A) and it looks like that fits for assembling a 3d printer so...
Do you think this model works good for the a 3d printer? (RepRap Prusa Mendel 3D printer)
Is it worth buy it?
US$: 19.52
Model: 42BYGH47-401A
Step angle:1.8°
Motor length: 47mm
Rated voltage: 2.8V
Rated current: 1.68A
Phase resistance: 1.68Ω
Phase inductance: 2.8mH
Holding torque: 62Oz-in/4400gf.cm
Lead wire: 4
Rotor inertia: 68
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Re: Lower Voltage But Louder Motors?
I dunno if comparing the unipolar with bipolar can actually give some conclusions, so i'd rather skip that fishy part.
> Are there common stepper motors out there that have a good torque range and micro-stepping but
> just aren't very well suited to RepRaps because of their electrical characteristics?
Yes, wront type are high inductance ones, and generally means thin wiring + extra turns, so also are a kind of a high coil resistance. For example if the coil resistance is 30 ohms. Or voltage written on the label is 12V, neither are good, in spite of the fact we will actually use it at 12v. Both need to be lower, ideally. From the link of mr Nophead here in the tables at the bottom you can see that second motor with 35ohms, 14v, and 44mH is of the wrong kind. As a side note anyway, motors dont have microstepping, but drivers do.
> Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range.
"The ROSC terminal has three settings:
▪ROSC tied to VDD — off-time internally set to 30 μs, decay
mode is automatic Mixed decay except when in full step where
decay mode is set to Slow decay
▪ROSC tied directly to ground — off-time internally set to
30 μs, current decay is set to Mixed decay for both increasing
and decreasing currents for all step modes.
▪ROSC through a resistor to ground — off-time is determined
by the following formula, the decay mode is automatic Mixed
decay for all step modes. tOFF ≈ROSC⁄825, Where tOFFis in μs."
> Should I favor the old motors on the basis that they're (a) quieter, (b) require less current,
> and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
If i were you i would choose to stay with bipolar ones, yes, and specs like 2.6v ~1.6A ~1.6ohms looks ok.
> Are there common stepper motors out there that have a good torque range and micro-stepping but
> just aren't very well suited to RepRaps because of their electrical characteristics?
Yes, wront type are high inductance ones, and generally means thin wiring + extra turns, so also are a kind of a high coil resistance. For example if the coil resistance is 30 ohms. Or voltage written on the label is 12V, neither are good, in spite of the fact we will actually use it at 12v. Both need to be lower, ideally. From the link of mr Nophead here in the tables at the bottom you can see that second motor with 35ohms, 14v, and 44mH is of the wrong kind. As a side note anyway, motors dont have microstepping, but drivers do.
> Obviously my new motors are within the range of the Vref pot on the driver, but in a slightly higher voltage range.
"The ROSC terminal has three settings:
▪ROSC tied to VDD — off-time internally set to 30 μs, decay
mode is automatic Mixed decay except when in full step where
decay mode is set to Slow decay
▪ROSC tied directly to ground — off-time internally set to
30 μs, current decay is set to Mixed decay for both increasing
and decreasing currents for all step modes.
▪ROSC through a resistor to ground — off-time is determined
by the following formula, the decay mode is automatic Mixed
decay for all step modes. tOFF ≈ROSC⁄825, Where tOFFis in μs."
> Should I favor the old motors on the basis that they're (a) quieter, (b) require less current,
> and (c) have plenty of unipolar torque? On the other hand the new motors are a bit prettier than the old ones.
If i were you i would choose to stay with bipolar ones, yes, and specs like 2.6v ~1.6A ~1.6ohms looks ok.
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Re: Is it worth buy and use this motor?
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wrecking stuff
i found this motor small stepper now im cosidering building something around the motor
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Controlling MDrive 23 ( schneider elect ) with Python....
hi all...this forum looks like it has the group of people I need...the SE site is for the pros of interface design
and I'm trying to work with linux and python.
I've got the linux program screen to connect to the motor (Via USB /dev/ttyUSB0 ) and make the motor execute basic commands.
However my PySerial commands haven't worked yet...and I'm lost now.
I don't understand some communication details and what to configure them as, other than baud rate...
parity, stop bits, num of bit/byte...
Cheers,
wbg
and I'm trying to work with linux and python.
I've got the linux program screen to connect to the motor (Via USB /dev/ttyUSB0 ) and make the motor execute basic commands.
However my PySerial commands haven't worked yet...and I'm lost now.
I don't understand some communication details and what to configure them as, other than baud rate...
parity, stop bits, num of bit/byte...
Cheers,
wbg
import serial
ser = serial.Serial('/dev/ttyUSB0', 19200)
ser.isOpen() # returns True
ser.write('ma 100000\r\n') # does nothing...
ser.inWaiting() # returns 0
ser.close()
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