Dear Mr. Dunning-Kruger:
randywiz81 wrote: ↑Mon Jun 06, 2022 3:08 pm
... Although not an industrial connector, the DB9 will handle the load of N.W. stepper motors due to the load sharing of two pins per phase conductor.
...right up until one of those wires breaks. Or a solder joint cracks and starts to corrode in the humid air, turning itself into a resistor.
In reality, between the 28Ga wires in their serial cables, and the DB-9 pins, whether it "will handle" the current is a matter of how much temperature rise
you're willing to accept, and whether that will outright melt, or simply accelerate the aging of the insulation.
There are a LOT of different connectors you don't have to buy in bulk that are far safer than what they did. With even a simple search on Amazon
you can find five sets of 4-pin "Aircraft" connectors (panel mount male + cable mount female) that have 5A ratings on each pin. If you're doing a 4th axis,
and you took the time to replace the connectors, you'd have one extra for when you futz the soldering on the first one. Twelve bucks or a potential
fire...your choice. You spent all that money to make a 4th axis, but go el-cheapo on the connectors?
https://www.amazon.com/Aviation-Connect ... B07793H4CV
Heck, you'd have a better setup if all you did was get a solder-cup DB-9 and hand-solder 20Ga wires for the cable. At least those would easily carry
the current even if only one pin-set was in use. For me, I've removed the driver modules from the Shark controller, and replaced the motors with
4Nm (560 oz-in, double what's on the HD2/3/4 series) hybrid stepper-servos and the appropriate driver modules. 48V 8A power supplies, one per
axis. Gobs of torque, over 400 IPM rapids and I use 18Ga wiring from the module to the motors. Oh...and instead of 1600 steps per inch (200 steps/rev
in the motor and 8x micro-stepping), I now have 20,000 steps per inch. That's right, 0.0001" resolution. I take the logic-level step/direction signals
directly off the controller board and send those to the driver modules. I don't even use their metal box anymore.
And yes, I **am** an electrical engineer; I don't "play" at it one little bit. I always love how people who have figured out how to connect stuff together
think they're somehow doing engineering. Bless Y'er Heart!
What I find interesting is that after you make your pronouncement, you then disclaim that everyone's on their own. Way to own your solution.
Below is a diagram I cooked up recently, per someone else's request for the information.
Have a Nice Day.
Rando