Messages

41

General Mach Discussion / Re: Help with small change to homing routine for Z axis

« on: February 07, 2018, 12:59:16 AM »

Hi Marc,
before modifying the homing code:
in which status is the z-axis servo motor during the "overnight" period in the event you turned off the air assist ?
enjoy your day, philippe

42

General Mach Discussion / Strange observation with HOME switches - Mach3

« on: February 06, 2018, 02:49:18 PM »

I observe something strange with the following HOME switches settings:

in Mach 3, USB attached to a motion controller connected via LPT to a BoB:

pin 10 associated to Home X
pin 11 associated to Home Y
pin 12 associated to Home Z

There are three identical inductive sensors, wired to provide a CLOSED CIRCUIT when NOT actuated. Thus, when a individual sensor trips, the V difference sensed by each pin increases to some 4.2 V, a value well within the TTL range.

In operation, Mach 3 homes every axis individually (as well as ref them all) without fault. Can work.

However, on the Diagnostic Panel provided by Mach 3 there is something strange: if I actuate only of the three Homes, the states of all three input channels monitored by Mach 3 flip (i.e. turn yeloow on the GUI). This is only true when all three switches are connected and operational. If I perform this test with ONE sensor connected at the time, the diagnostic panel displays the expect and single state change only.

Even if this situation does not preclude safe homing operation, I feel it as sufficiently strange to seek for an explanation.   

The voltage change measured at each channel upon sensor actuation is coherent with expectation and TTL value range. 

Has anyone observed similar "strange" behavior ?
Thank you for any comment you may provide.

Regards, Philippe

43

General Mach Discussion / Re: Mach 3 hangs up at line 22

« on: March 08, 2017, 04:35:07 PM »

see for example

http://www.science.smith.edu/cdf/pdf_files/Techno_GCODE%20Commands.pdf

cheers, Philippe

44

General Mach Discussion / Re: Mach 3 hangs up at line 22

« on: March 08, 2017, 04:32:10 PM »

G1 is for a linear move to point X and Z, and F is for the feed rate. I do not know why the feed rate is F01 instead of F1.
Try to increase this number, a little, without the "0" in front. Hands on STOP, just in case.

45

General Mach Discussion / Re: Mach 3 hangs up at line 22

« on: March 08, 2017, 04:13:59 PM »

what is at line 22 ?

46

General Mach Discussion / Re: UC300 (USB) to Mach3 erratic connection losses

« on: March 08, 2017, 04:12:14 PM »

First of all, thank you to Everyone  who shared ideas and gave input. Here some feed-back.

- The Power management of a laptop may indeed play a role, but is not ( ), in this case, the main reason for erratic USB connection losses.
- The only work around ( not a sustainable solution ) that was identified is to run the rig with the laptop ON BATTERY only.
- For those who are interested, I have attached a scheme of the set-up.

This set-up deserves a few comments:

1) The 5V power supply for the UC300 and BoB can be a cheap "plug in the wall" device or a "lab grade low ripple" unit, the behavior is similar: erratic USB disconnection are observed unless, the laptop is disconnected from its 18 V PS.

2) Between TP1 and TP2 (see scheme), using the "plug in the wall" device, there is 68 V ac measured. The same amplitude is measured between the shield of the "plug in the wall" and any of the "0" and "5V" wires, when everything is connected. Main contribution is AC 50 Hz, shape is distorted from a pure sine, verified with a scope. If the 5 V PS is checked alone, this AC is "only" about 10V.

3) Between TP1 and TP2 (see scheme), the nasty 68V ac drops to 3 V ac (shape identical) when the "cheap" 5V PS is replaced by the "clean" 5V dc.

4) By design, the BoB has its PCB plane ground on the LPT connector.

5) The shield of the USB B connector on the UC300 unit IS NOT connected to the PCB plane by design. This link takes place in the laptop, when the shield leaving the computer is bonded to the "0V" of the USB connetor.

 

47

General Mach Discussion / Re: UC300 (USB) to Mach3 erratic connection losses

« on: February 22, 2017, 01:44:49 AM »

summary:

random disconnections between Laptop / Win 7 / UC300 still not zero despite modified power management settings AND USB rot hub adjustment.
ruled out the UC 300 by himself, it must be the combination of THIS PC to this USB device.
tested UC for two hours on another PC: zero disconnections.
 

48

General Mach Discussion / Re: UC300 (USB) to Mach3 erratic connection losses

« on: February 20, 2017, 04:39:12 PM »

not yet ... but you may have a point.

this (perhaps wrong) choice was motivated by a tight spec list, partially available equipment, and the fact that I have used USB as well as PCI stuff for (low level signal) data acquisition applications that I thought were more complex than feeding three drivers with pulses. But these jobs were not tailored for machining as Mach3 obviously is. If I neglect the loss of three days with this silly (not completely solved !) USB loss of communication the whole process (sketch / order three ball screws + motors + drivers / chop pieces / assemble together + wiring was reasonably flawless.   

49

General Mach Discussion / Re: UC300 (USB) to Mach3 erratic connection losses

« on: February 20, 2017, 03:39:36 PM »

I have no envy to solve it to the root. BTW, as we chat, the nasty disconnections are not entirely gone. Had three runs in a raw with 10'000 plus lines of code, the fourth stalled miserably ...
another beer, I guess. And, I have not moved a thing of the rig. ...

50

General Mach Discussion / Re: UC300 (USB) to Mach3 erratic connection losses

« on: February 20, 2017, 03:22:28 PM »

well, since you are/were in the IT business allow me to ask another question:

 is there a rationale for the change in erratic behavior ? why would the frequency of disconnections vary from time to time without any visible (to the User) correlation with the job given to Mach 3 ? the only coarse correlation I have is that the disconnection rate was higher with Mach 3 RUNNING than IDLE and clearly smaller (but not zero) without Mach 3.

 enjoy your evening, Philippe