On 4/25/23 12:51, Thaddeus Waldner wrote:
This is correct to some degree. A motor controller wouldn’t need need the dc-dc
controller, isolation transformer, and output diodes and filters, which
accounts for about half of the space to my reckoning.
Also, high voltage, low amperage motor controllers are usually more compact
than their low voltage counterparts. For example, you can buy a 12mm x 12mm
motor controller that includes pic+boost controller, motor sense circuitry, and
output stage, that will run a 100-watt motor.
Yeah, I have bought similar rail-mounted supplies in the past, though usually
it’s the Meanwell brand.
The application is refurbishing 1980s-era equipment. Original equipment has a
6000rpm 110v universal motor, usually with worn out bushings and brushes, and
faulty electronics. Replacement parts are generally available but getting
prohibitively expensive.
So a servo system would be overkill but nice, cheap, brushless motor with
bearings is ideal. Works a treat too, except the power supply doesn’t fit.
I apologize for the off topic content here but I do appreciate the input.
I don't consider it off topic at all. If not here, where else are you
going to get honest info about today's newer tech, w/o having to filter
out the advertising BS. Here, you get info from the user who has tried
it, and is reporting his success or failure.
These stepper/servo motors are slower than a universal, probably best at
1/3rd the revs of a universal, But if its a timing belt drive, pulleys
can be changed because these motor have several times the torque of the
universal and can move much more precisely. One of the reasons they, in
nema-23-24 sizes, come with an 8mm shaft is that higher torque, And as
the nema-17's get stronger, I expect to see nema-17's will grow bigger
shafts than 5mm, its already hell to keep the pulleys grub screws tight
as they approach 1 nm in torque in a 3d printer.
While I'm expounding, there are now smaller versions of these motors
that use a hall effect encoder. If using them for precision movement,
they won't because the 5 milliseconds time delay in converting the hall
effect to a digital encoder's quadrature format means that if the motor
is moving, the feedback from the encoder is always that 5 milliseconds
stale, so it moves in jerks, large jerks if turning fast. On 3d
printers, the 42C motors have been all been removed because their prints
are shingled. Optical encoders are fine, hall effects aren't.
[...]
Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
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