Stepper motor model?

[PaulS]

anyone got a line on good replacement stepper motors?

[PaulS]

@Walter, this is the link to the stepper drivers on the Duet WiFi i already ordered and motors i am looking at. I am a bit confused but am i right in thinking the motors are 400 steps but the driver is only 256 step? any way to use 400 or am i once again in the land of OVERKILL?
https://www.trinamic.com/fileadmin/assets/Products/ICs_Documents/TMC2660_datasheet.pdf

US Stock 4 PCS NEMA17 0.9° Stepper Motor 40mm 400 steps/rev 3D Printer CNC Robot | eBay

[Walter]

Yep : confusion!

Short answer, will be driving ...
400 steps for motors is 400 steps per revolution = 0,9° per step.
Drivers give indication of microsteps per step. Typical for i.e. polulu is 16 microsteps per step. This is the real stepcount the MKS sends to the driver to rotate one physical step.
Means for one revolution for a 400 steps per revolution stepper, the controllerboard has to send 16x400 step pulses to the driver.
A TMC interpolates these microsteps with an extra 16 (micro-micro?) steps But these you can not influence. The stepperdriver does this autonomous.

Microsteps are there for making movements even more smooth
Normal arduino-like boards like the MKS have problems with speed due to slower processors. They can send all the necessary steps to the stepper but when trying ro move real fast, they hit their limits quite fast. The Duet doesn't have this problem. Processor is at least 10 times faster end is able to send out the pulses fast enough even for high speeds.

Away now ...

[PaulS]

"yes we have a spec sheet if you go to this link and click on the second picture for the motor you will see the spec sheet.
https://folgertech.com/products/nema17-17-stepper-motor-5000g-cm-3d-printer-reprap-medel-prusa
hope this helps
Thanks,
Folger Tech Team"

Like i said, crazy fast email replies. got to luv that!

Great breakdown on micro stepping

[PaulS]

Step angle
There are two common step angles: 0.9 and 1.8 degrees per full step, corresponding to 400 and 200 steps/revolution. Most 3D printers use 1.8 deg/step motors.

Aside from the obvious difference in step angle:

0.9deg motors have slightly lower holding torque than similar 1.8deg motors from the same manufacturer
However, to produce a given torque, the lag angle needed by a 0.9deg motor is slightly more than half the lag angle of a similar 1.8deg motor. Or to put it another way, at small lag angles a 0.9deg motor has nearly twice as much torque as a 1.8deg motor for the same lag angle.
At a given rotation speed, a 0.9deg motor produces twice as much inductive back emf as a 1.8deg motor. So you generally need to use 24V power to achieve high speeds with 0.9deg motors.
0.9deg motors need step pulses to be delivered to the drivers at twice the rate of 1.8deg motors. If you use high microstepping then the speed could be limited by the rate at which the electronics can generate step pulses. The interpolation mode of the TMC2660 drivers on the Duet WiFi can be used to overcome this issue.
https://duet3d.com/wiki/Choosing_stepper_motors
@Walter looks like the big difference between .9 and 1.8 degree steps. Question i have is 24 volts really necessary? do i need that much more torque?

[Walter]

I have moved to 24V mainly for the lower current to the hot end heater (half the current of a 12V system) means also half the losses in the cabling. As a side effect better performing steppers.
Is also a smaller power supply with 7Amps and no fan.

[PaulS]

@Walter I fear i will have to do the math on this to know for sure. Since i have a 110v 750 watt bed heater, next to no amps there from the board so should have some to spare.PS is way more than needed so added a 6 ch fan controller for some additional cooling and leds but that doesn't get driven by board either so should be NA as well (including hotend fan always on but with front panel control). cheaters math is 4.69 kg-cm for upgraded motor (17HM19-2004S) vs 3.3 kg.cm for stock. Even at less than ideal 24 volts, i should be same or better torque and 400 steps right? Got amps to spare so volts shouldn't be a big issue? With 2 axis running 2 motors rated at 2 amps and the driver maxing out at 2+ amps...(possible upgrade coming via firmware) best guess is 24v is ideal but will 12 v mess up the wave forms under load? Ugh this is why i got out of EE, way too much crazy math not to mention needing an oscope again LOL

[Walter]

The TMC's can handle far more current then the steppers. What is the correct current rating for the steppers? The value on the small label on the stepper stating 1,5A or the value from the blurred specsheet on the FT-website stating 0,4A. Is the first one something about peak current and the other nominal/continuous/RMS current? I don't know. If it is 0.4 RMS then peak would be 0.4 times 1,4142 (sqrt of 2) is 0,56 amps.
Anyway : you could give each stepper it's own driver with the duet+stepper expansion board.
Now I handle Z and Y with 1.3 amps for 2 steppers. If they behave identically (electrical point of view) current per stepper would be half of that.

Some more confusion : FT5 specs on FT website : x6 NEMA 17 5.0kg/cm Stepper Motors
Torque is specified in kg.cm or Nm but not certainly not kg/cm.
If it is 5kg.cm then this would be 49N.cm
The max torque on the 'specsheet' is 260mN.m (milli Newton meter) which is 2,6 kg.cm

So draw your conclusions ...

[csorrows]

Normal arduino-like boards like the MKS have problems with speed due to slower processors.

Please be specific when referring to either the stock MKS 1.4 or the MKS SBase or other MKS boards. The MKS 1.4 (8-bit) is underpowered for high speed high step setups yet the MKS SBase (32-bit) is quite capable. I do not want to create confusion for other users.

[Walter]

@csorrows Sorry!
As a MKS GEN 1.4 user I tend to forget the MKS Sbase board and referring to MKS without suffix allows for misinterpretations.

As Chris states the genuine FT5 MKS GEN 1.4 is quite different from the MKS SBASE.

The MKS GEN 1.4 board is based on the 8 bit ATmega2560 at 16MHz, the MKS Sbase on the contrary is based on an 100MHz ARM Cortex M3 32 bit processor and has virtually no limits in processing speed for a 3d printer.

[csorrows]

Wrong Chris buddy.

[PaulS]

Thanks Walter, as usual right on the money! I couldn't trust the spec sheet either... i ordered 6 motors last night. Not to be a Debbie downer or anything as it is a far cheaper alternative to 32 bit but the MKS Sbase has some less than ideal stepper drivers which is why i looked for a higher end option. It is capable of 1/32 steps but is known to be flawed and can have issues which i am guessing from all the videos on line will adversely affect print quality.

DRV8825 missing microsteps

Manufacturer Part Number 17HM19-2004S
Motor Type Bipolar Stepper
Step Angle 0.9°
Holding Torque 46Ncm(65.1oz.in)
Rated Current/phase 2.0A
Phase Resistance 1.4ohms
Recommended Voltage 12-24V
Inductance 3.0mH±20%(1KHz)

[PaulS]

here is a pic as best as i could get from the low res doc on FT web site. i did ask for clarification so am curious what i will get for a reply. They have been greased lightning of late so fingers crossed...

[PaulS]

forgot to mention that i plan on building another printer along the lines of the ft5 after frank-n-printer is done. Since i have everything but the frame and decent power supply, i should be able to throw together a plan b printer for next to nothing which is a good thing since i have spent so much upgrading my 1st 1. Certainly not wasting anyone's time on a fools errand...

[PaulS]

can't complain about their response time! here is the official reply.

Hello Paul,
Yes as you noticed the spec is incorrect on the website. we have contacted our vendor for a new updated spec sheet.
Once we hear from them we will notify you i am sorry for this inconvenience.
Thanks,
Folger Tech Team

[Traveler]

I am a big fan of the quality motors by Kysan. Manufacturer's Part Number 1124090

http://www.tridprinting.com/Electronics/

[wewin1]

Will this stepper motor work on the FT-5?

Stepper Motor Nema 17 Bipolar 40mm 64oz.in(45Ncm) 2A 4 Lead 3D Printer Hobby CNC

[Walter]

Yes it will. Something wrong with the standard steppers?

[wewin1]

I was looking at getting a spare motor.

[Maxheadroom1]

Is it more simple to just use the same stock stepper motor from FT-5 on the E3D titan extruder?