[chbot] Question regarding stepper motors

[Mark Atherton]

It's notoriously difficult to measure these kind of resistances using 
the two-wire method, so please double check before going any further.

Do you have a 4.7 ohm resistor you can read using the same meter, just 
to verify test meter lead resistance

or pass a known 200mA thorough the phase (with one meter on current in 
series), and measure voltage directly across the phase using a second meter.

-----

If you can't do either of the above, what resistance do you get when you 
short the meter's probes together ?

slowly, slowly ...

- Mark




On 24/02/2020 2:42 PM, Michael Dawson wrote:
> OK Measuring 5.7 ohms through a phase.
>
> Does this suggest it's not a 1.33A?
>
> Cheers
> Michael
>
> On Mon, 24 Feb 2020 at 14:24, Mark Atherton <markaren1 at xtra.co.nz 
> <mailto:markaren1 at xtra.co.nz>> wrote:
>
>     So, a bit like https://www.banggood.com/search/990669.html
>
>     Looks like the standard length is 34mm, colours may be standard,
>     and weight is 220g. Allowing 12g for your gear, this all sounds
>     very similar..
>
>     Your part number is D42HSC1413B-24, so it looks like the D42 part
>     could be associated with faceplate size.
>
>     googling "d42hsc" stepper motor indicates that d42hsc may be the
>     family of the part you are looking for.
>
>     The DC resistance of the Bangood part above is 2.1ohms per phase.
>
>     If you can measure low resistances with accuracy, see what your
>     resistance is for one phase. Or pass 200mA through a phase and
>     measure volt drop.
>
>     -Mark
>
>
>
>
>
>
>     On 24/02/2020 1:32 PM, Michael Dawson wrote:
>>     4 wires into a 6 wire plug, colours from left looking towards the
>>     motor, black, space, red, green, space, blue.
>>     Dimensions 42mm x 42mm Faceplate x 33mm depth of motor.
>>     232 grams weight including cog, can weight without that is that
>>     would help.
>>
>>     Cheers
>>     Michael
>>
>>     On Mon, 24 Feb 2020 at 13:06, Mark Atherton <markaren1 at xtra.co.nz
>>     <mailto:markaren1 at xtra.co.nz>> wrote:
>>
>>         Hi Michael,
>>
>>         Welcome aboard.
>>
>>         A few parameters which may be useful:
>>
>>         - How many wires, what colours
>>
>>         - Overall dimensions
>>
>>         - Weight
>>
>>         Regards, Mark
>>
>>
>>
>>         On 24/02/2020 12:25 PM, Michael Dawson wrote:
>>         > I am trying to calibrate the A4988 drivers for the stepper
>>         motors for
>>         > my laser engraver/cutter, using Arduino Uno and the CNC
>>         shield,
>>         > (because the one that came with the cutter was pirated
>>         software and
>>         > didn't work how it was supposed to and I want to run
>>         laserGRBL anyway).
>>         >
>>         > The issue I am having is, I have not got the specs for the
>>         stepper
>>         > motors and aliexpress did not provide the specs.
>>         >
>>         > I think they are nema17, but the only hint I have to that
>>         is that when
>>         > I search on the number etched into the motors D42HSC141B-24
>>         I find an
>>         > old banggood ad saying they are nema17 but if you click on
>>         the link
>>         > the original ad is long gone.
>>         >
>>         > I currently have them set to 0.952v when measured connected
>>         to the
>>         > arduino and cnc shield which is what was suggested, if they
>>         were rated
>>         > to 1.7A. I'm hoping that is correct for these steppers, so
>>         I guess my
>>         > question is does anybody have these same steppers and know
>>         the specs,
>>         > or do they know it they are indeed rated to 1.7A
>>         >
>>         > Or is there a way to find the Amp rating other than the
>>         etching on the
>>         > side of the stepper?
>>         >
>>         > Any help would be much appreciated.
>>         >
>>         > Oh hi BTW, my name is Michael, one or two of you may know
>>         me, I ran
>>         > Red Dwarf BBS back in the day, (I just remembered, I had
>>         the Red Dwarf
>>         > logo display in RIP script when you logged in, pity that
>>         never really
>>         > took off.)
>>         >
>>         > Michael
>>

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