Messages

1

SmartBOB controllers and dedicated accessories / Re: PMDX-424 driving Gecko G214

« on: December 15, 2016, 08:35:36 PM »

Thanks Steve!
(modified/simplified as I get things figured out)

I might have a problem supplying +5V to all 5 G214 drivers...  According to the G214 manual, each one requires 5V@15mA  (75mA total).  Based on the PMDX-424 information, it looks like I'm limited to 24mA.  If the PMDX-214 can't provide enough current can I use an external +5V PS? How would grounding be handled? 

2

SmartBOB controllers and dedicated accessories / PMDX-424 driving Gecko G214

« on: December 12, 2016, 02:55:09 PM »

Does anyone have any experience driving the new Gecko G214 Stepper Motor Drivers with the PMDX-424 motion controller?

I currently have Gecko G203V's, which have a fixed native 10u-step resolution.  I can't get the minimum positioning resolution I need and Hardware reconfiguration isn't an option.
I'm considering the newer Gecko G214's because they have selectable resolution, as well as many other new features.

Comments?

3

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Gantry squaring (master AND slave drive limit switches)

« on: October 11, 2016, 02:02:15 PM »

Thanks Bob
WOW!  I now understand why PMDX is working a gantry squaring effort to support the PMDX-424.  Never imagined that the MACH4 solution could be such a can of worms!

Looks the best thing would be to wait for the PMDX squaring solution.  Hope you can help us out soon.

On the bright side -- at least I know how I should wire the PMDX-424 to my motor drivers now.

4

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Gantry squaring (master AND slave drive limit switches)

« on: October 10, 2016, 02:30:42 PM »

NOTE: The SmartBOB plug-in does not currently support gantry squaring, either on the PMDX-424's Motor3A/3B hardware slave, or using Mach4 to configure the master/slave motors.

I assume that BOTH methods will eventually allow you to step the two gantry motors separately. 

(Bob; can you please verify the information provided below.  if not, please remove this so it doesn't add confusion) 

PMDX-424 SOLUTION:
MACH4 setup is configured to recognize the PMDX-424's M3 to drive the gantry.  MACH4 "thinks" this is just one motor.  The PMDX-424; M3a output drives one gantry motor, M3b output drives the other gantry motor in the opposite direction.  The squaring solution would have to be a software routine, designed into the SmartBOB driver software, that would allow for separate movement of M3a and M3b. 

MACH4 SOLUTION:
MACH4 setup is configured to recognize the PMDX-424's M0 and M3a to be the two gantry motors.  MACH4 configuration setup would need to have one of the two motors operate in reverse direction or reverse the wiring on one of the two motors.  The squaring solution would need to be done through a family of MACH4 scripted routines that would allow individual movement of the PMDX's M0 or M3A.

Once PMDX gets gantry squaring working, I'm betting this would be a preferred method.  In the mean time, I'm wondering if anyone has gone to the trouble of writing the necessary scripts to use the MACH4 solution?

5

Cables, connectors, switches, contactors, sensors and other items / Re: Proximity Sensor Recommendations

« on: July 21, 2016, 11:18:58 PM »

Thanks Steve. 
My previous limit switch design was such that over-travel would result in crashing into the switch.  Retrofitting with proximity sensors gave me a chance to fix this situation.  Just received 4 of the PMDX-Prox-01's.  Looks like very high quality parts. 
I'm guessing that +/- .002 repeatability over the 50-55" gantry length should give great results.  I'd almost bet that standard 4x8 plywood sheets are somewhere within this range.  It's a good starting point anyway.
My revised PMDX-424 solution now uses all 8 available inputs:
1&2 are microswitch limits for the +/-Z axis
3&4 are microswitch limits for the +/-Y axis
5&6 are Proximity sensors on both -X ends of the gantry (for squaring)
7 has Proximity sensors on both +X ends of the gantry (wired in parallel)
8 has a connection for a Zero Z axis touch-plate.

Bob - thanks for commenting on Gantry Squaring!
I urge you to have manually entered offsets in your initial release of gantry squaring.  I can think of two reasons:
(1) Can't think of a better way to distinguish the PMDX solution.
(2) If the repeatability of the sensors is +/- .002 it would be extremely hard to tweak sensor/target mounting to this level without additional manually input offsets.

Thanks again for all you help and support

6

Cables, connectors, switches, contactors, sensors and other items / Proximity Sensor Recommendations

« on: July 16, 2016, 12:07:03 PM »

I'm building a 3-axis CNC router with PMDX-424 and tandem X axis motors.  I had a single motor, prior to the tandem x-xis upgrade.  In anticipation of gantry squaring in the PMDX-424 plug-in, I've wired my X-axis motors to "Motor 3a & 3b".  I assume the gantry squaring process would work better with something passing across the face of a sensor vs. approaching it.  I originally used Micro-switches that are positioned poorly for this.

I'm considering re-doing the x-axis with 4 proximity sensors - probably the PMDX-PROX-01.  To make this work, I'd need to attach a plate to each side of the gantry.  The plate will be positioned to pass in front of the face of each sensor - at or near the end of X-axis travel.

I'm hoping that the gantry squaring software will use an initial setup process where offset parameters, for each end of the gantry, can be measured an input as constants.  It would be difficult and tedious to adjust the sensor/plates so that they simultaneously trip - only when the gantry is square.

Will the use of proximity sensors, such as the PMDX-PROX-01, provide the repeatability necessary to square the gantry?

I'm also hoping you can comment on the availability of Gantry Squaring.

Thanks.

7

Parallel Port breakout boards, motherboards, and dedicated accessories / Re: PMDX-179 Reset Button

« on: May 24, 2016, 12:31:09 PM »

Pictures of the PMDX-424 show J4 and J5 terminals, located immediately behind the board mounted reset pushbutton.  I was hoping these were pin-outs that involved the reset button and would allow me to wire something externally - like the reset button on the PMDX-179-PAN.

Where did you see these pictures?

Bob

The picture of the PMDX-424 on your web side shows a pin header on J4 and plated through holes on J5.  The unit I received had plated through holes for both J4 and J5.

Sounds like the best approach is to wire the big green reset button to one of the PMDX-424's unused input lines and configure it through the Mach4 setup.  I see advantages this way.  It would allow changing the exact function if needed. 
Thanks for the help
Dave 

8

Parallel Port breakout boards, motherboards, and dedicated accessories / Re: PMDX-179 Reset Button

« on: May 20, 2016, 03:14:53 PM »

Thanks Bob;

Was thinking the large green button might somehow be used to duplicate the function of the circuit board mounted reset button on the PMDX-424.  My '424 is mounted deep inside the electronics box, where the reset button on the board won't normally be accessible.   That's why I got the PMDX-179-PAN in the first place.

Pictures of the PMDX-424 show J4 and J5 terminals, located immediately behind the board mounted reset pushbutton.  I was hoping these were pin-outs that involved the reset button and would allow me to wire something externally - like the reset button on the PMDX-179-PAN.

 
 

9

Parallel Port breakout boards, motherboards, and dedicated accessories / PMDX-179 Reset Button

« on: May 18, 2016, 06:40:04 PM »

How would the Reset Button on a PMDX-179 Remote Status Board be used with the PMDX-424 SmartBOB?

10

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Source for Gecko 203V Disable Voltage

« on: April 25, 2016, 11:04:51 AM »

Really pleased with all the technical information I'm getting from PMDX as I work my build.
Thanks again Bob!

11

SmartBOB controllers and dedicated accessories / PMDX-424 Source for Gecko 203V Disable Voltage

« on: April 23, 2016, 12:38:03 PM »

Gecko 203V's have a disable terminal.  Their manual says that you can force winding currents to ZERO by connecting this terminal to the Step/Direction controller's +5V.

I'd like to tie all 4 of the 203V's disable terminals to a single switch, then to 5V, somewhere on the PMDX-424.

(1) can I tie all 4 of the 203V's disable terminals together without causing problems?
(2) what's the best place, on the PMDX-424, to get the 5V from?

thanks
Dave

12

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Tandem Motor Configuration

« on: April 12, 2016, 08:22:30 PM »

Bob;
Thanks for the really complete description on tandem axis support.  Mach4 and the PMDX components have far more flexibility than I ever imagined. 
 
I need to get Mach4 running so I can quit asking questions and do some real work here.

13

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Tandem Motor Configuration

« on: April 12, 2016, 03:38:36 PM »

I guess I should explain that all the questions are the result of me having NOT experimented with the hardware and MACH4.  Sort of flying blind here as I try to determine an optimum hookup that will allow for the future.

From what Bob described, the PMDX-424 feeds its Motor 0 through 3 signals to the PMDX-134 through the 26-pin ribbon cable.  Creating a tandem motor configuration is done within the MACH4 software.  Signals from the PMDX-424's Motor 3B terminal block is never sent through the 26-pin ribbon cable.

If future axis squaring will be done by PMDX-424 plug-in software, then I would assume it will rely on the use of the gantry motors being connected to Motor3A and Motor3B.  Since Motor3B signals don't go through the 26-pin ribbon cable, it looks like future axis squaring will be unable to work with the ribbon cable and the PMDX-134. 

I really like the PMDX-134 concept, but I want to be wired correctly for the future. 

14

SmartBOB controllers and dedicated accessories / Re: PMDX-424 Tandem Motor Configuration

« on: April 11, 2016, 08:24:14 PM »

The PMDX-424 has 5 motor outputs.  The PMDX-134 has 4 motor drivers.
The PMDX-422, with 4 motor outputs, was easy to understand.  I'm not clear how mapping is achieved with the PMDX-424, using the same 26-pin ribbon cable.
Could you please explain?
(thanks)

15

SmartBOB controllers and dedicated accessories / PMDX-424 Tandem Motor Configuration

« on: April 10, 2016, 07:50:48 PM »

Will the PMDX-424, wired to a PMDX-134 Motherboard with a ribbon cable, support a Tandem Motor configuration?

I have the PMDX-134, populated with (4) Gecko G203V's.  I want this to drive a 3-axis router with tandem x-axis (gantry) motors.  I'm anticipating the software's ability to do axis-squaring.

Thanks