Hello Guest it is March 28, 2024, 06:44:49 AM

Author Topic: USB to Parallel port motion controller for Mach 4  (Read 611 times)

0 Members and 1 Guest are viewing this topic.

USB to Parallel port motion controller for Mach 4
« on: September 03, 2021, 11:56:54 AM »
Hi there, Just want your opinion on which USB to Parallel port controller to use. I'm currently using a PDMX 411, it is an awesome controller, however I can't get it to probe with my system. I've contacted Steve Stallings several times about the issue, but it hasn't been resolved. So my questions are, is there a better controller out there? Will I still have the probing issue with another brand of controller, Should I just upgrade the whole controller board to a USB Board, if so which one. Which company that sells the motion controllers has a excellent technical service? I've been using my CNC Mill for almost 20 years, however I'm not a expert when it comes to the electronics that run the motors. So what do you think?

Pat

Offline Bill_O

*
  •  562 562
    • View Profile
Re: USB to Parallel port motion controller for Mach 4
« Reply #1 on: September 03, 2021, 03:27:25 PM »
If you are going to change I suggest getting away from the USB and going to Ethernet.
Re: USB to Parallel port motion controller for Mach 4
« Reply #2 on: September 03, 2021, 06:20:47 PM »
Hi,
there are three USB-to-parallel port external motion controllers that have a Mach4 plugin, the PMDX411, the UC100
and the PoKeys 57CNCdb25. They near as dammit identical to each other.

Of the half dozen or so companies that make Mach4 ready controllers Steve at PMDX IS the gold standard for support of
his products. There are others that come close to Steve, but none that exceed his commitment to his customers.

All the other controllers use Ethernet connections which has much better electrical noise immunity and lower latency.
One further issue with the USB-to-parallel port controllers is that by definition they can have only one ports worth of
IO, ie 17 inputs/outputs, which is hopelessly too few.....for my machine anyway.

I use an Ethernet SmoothStepper by Warp9TD and have done for seven years. It is Ethernet connected naturally, has three ports
of IO, ie 51 inputs/outputs that run up to 4Mhz, a huge increase over the majority of the competition. The ESS all but requires a
breakout board or boards, you can use from one up to three C10's at $23 each, right up to an MB3 by CNCRoom ($180) that has
all three ports developed, ie 51 inputs/outputs with a good balance between inputs and output, including relay contacts and
PWM output for spindle control.

I have just commissioned my new build mill which runs three 750W Delta servos, that like most servos uses 24V signaling,
and to achieve max signaling speed for Step/Dir inputs I've used 5V differential signaling. I elected to design and build my
own breakout board so it that has exactly what I want and no stuff that I don't. I have split the design into two boards:

1)10 5V differential outputs for up to five servos
 Reset and Enable outputs commoned to all five servos
 5 Alarm inputs, one for each servo
 1 24V switch activated by the Enable output for Z axis brake

2)26 inputs (24V sourcing, so all active low)
 1 Relay output for VFD
 1 PWM output for VFD
 6 General purpose outputs (sourcing and sinking 24V at 50mA)

These two boards are in service and working well. I will post circuit diagrams and PCB layout should anyone want to make their own.

Craig


'I enjoy sex at 73.....I live at 71 so its not too far to walk.'