Re: [CAD_CAM_EDM_DRO] motor grounding and DB9 connector question

resosys wrote:

>
> Also, I have been designing my system with DB9 connectors for the
> motor connections. I will be running 55V at a maximum of 7amps and
> want to make sure the connectors are up to the task. Does anyone
> have a link to specs for common connectors?

I believe each pin is good for 2 amps, and as a (standard 2 phase
bipolar) stepper needs 4 power lines, I think you might be restricted
to 4 amps (ie four paired wires, and maybe a ground).

Someone here was using a DB25 (perhaps it was Al Schoepp)

and he uses four bundles of four wires, leaving 9 wires
for other functions (limit switches etc).

I think the 55 volts is probably exceeding the original connector
specs by a great deal, so I don't think a DB9 is a great idea
(with your 55 V and 7 amps).

---------------------------------------------------------------

These days I am just dispensing with the connectors, running
the wires into the box through a rubberized plastic weatherproof
cable strain-relief socket, available at any electrical dealer.
It comes with a selection of rubber inserts to match your wire
bundle diameter, and hold them snug.

Using the DB9 might be better suited to bringing in the encoder
signals (you'll want to keep the encoder signals away from the
power cables in any case).

Doug Fortune
http://www.cncKITS.com