Messages

11

FAQs / Re: Losing steps or something?

« on: November 18, 2010, 04:19:31 AM »

I didn't get to do very much today but the diagonal program repeated perfectly both at accelerations of .5 and 10 units per sec. squared.  I never had that luck before.  I'm thinking we Did it!.  Why the strange PP signals Is still a mystery though...  Having the second port and a third that will work with my Z-bot jog dial MPG will be great.  Thanks for the help, guys. 
Don

12

FAQs / Re: Losing steps or something?

« on: November 17, 2010, 04:47:32 AM »

Don't know...  I'll try putting the whole machine though trial runs tomorrow, though.  I hope this is the solution...   Don

13

SmoothStepper USB / Strange Warning Message

« on: November 17, 2010, 04:45:29 AM »

Hi, I just installed a Smooth Stepper in My mill, and when I start the Mach3 up, I get a warning message that reads:  Port 1 Pin 2 is assigned 2 times,
Port 1 Pin 3 is assigned 2 times, etc.  One line for each of the outputs I am using, pins 2 through9.  I de-selected the parallel ports in the ports and pins section but the message persists.  What does it mean?  Otherwise than that, the unit looks to work perfectly.  Don

14

FAQs / Re: Losing steps or something?

« on: November 17, 2010, 04:38:48 AM »

Hi, Guys.  I ordered a SmoothStepper last Thursday, and it arrived Monday.  I've installed it and I will post pictures of its outputs.  It looks promising.  No more jittering and the Direction signal is a STEADY! state.  Steps are stable also.
Don

15

FAQs / Re: Losing steps or something?

« on: November 08, 2010, 03:34:44 PM »

I just tried the jog mode.  Set the Dir Pin to Pin 2 hooked up the scope to pin 2 and ground, terminated the pin with a 4.7k resistor to ground, and set the jog rate to 30% feedrate.  Note that the little ticks on the lower part of the trace are the screen reticle.  The timing of the direction "Pulses" seems to be varying, even across the screen.  When I ran jog at 100%, the trace was jittering and flickering.  Not steady.  It is definitely not setting a steady state!

16

FAQs / Re: Losing steps or something?

« on: November 08, 2010, 03:17:35 PM »

Hi, again Dan.  It appeared after I installed the dwell in the program that the offsetting went away except at the extremely slow acceleration rate of 0.5...  Why would very slow accel. cause the steps/direction signals to malfunction?  The fact that sometimes the pulses are leading vs. lagging bothers me a lot.  I would expect that the direction pulses ( if they are supposed to be pulses) wouls stay in the proper timing sequence.  The two O'scope pictures show clearly a timing difference, sometimes during the same line  of code execution. 
Thanks for the help, Don

17

FAQs / Re: Losing steps or something?

« on: November 08, 2010, 03:10:16 PM »

Driver test.

18

FAQs / Re: Losing steps or something?

« on: November 08, 2010, 03:09:01 PM »

Hi, Again.  First, Duh!  The 1Volt O'scope readings are my fault.  The variable gain on the scope was set.  Now the traces show 3V logic for everything.  I've moved the pins around in Mach and the stepped direction signal is always there.  The wierd thing is that the steps lag the dir pulses sometimes and sometimes not... 
2 Questions that come to my mind are: 1) Why is the Direction signal a pulse?  2) Why is the timing of the pulses changing?
I'll post a picture of the driver test, showing tha it is acceptable...  I think.

Dan.  I'll hook up the Breakout board and try to hook up the scope to its outputs.  However, I didn't see any change recently going from direct connection from Mach to the Geckos vs. Mach, BOB, Geckos.  It is worth a try, though.  I suspect something in the computer is the problem.  But what?  Only Windows XP and Mach 3 are on it.

19

FAQs / Re: Losing steps or something?

« on: November 07, 2010, 10:39:04 PM »

The photos, I hope.

20

FAQs / Re: Losing steps or something?

« on: November 07, 2010, 10:38:07 PM »

I recalled that the PMDX BOB has a demo mode...  It moves the X axis 1024 steps, then moves the Y axis 1024 steps, then moves the X axis back 1024 steps, then moves the Y axis 1024 steps back.  Then is continues this cycle until the start button is depressed again.  It occurred to me that if I started with the Dials on 0.000, then I could see if the Drives and Motors were repeating.  The demo mode runs at 100 pulses per second, slowly but with no ramping/acceleration.  After running this program for about 2 hours, it had not offset at all.  Thus I believe the Geckos and their associated wiring are working correctly. 
   I wrote a dwell into the program.  It now has a line that reads G4P1 before each G1 line.  Running the machine from the computer, I discovered that There was no offsetting behavior until I set the acceleration to 0.5.  The I got -.010 offset in 100 iterations.  Any faster acceleration up to 10 was fine.  I didn't try any faster acc. Rates.  I swapped the outputs in Motor Outputs and swapped the wires at the BOB output.  Results are the same.
   I disconnected the BOB and hooked up my cheater cable, this time I terminated the leads to common with 4.7k resistors.  The O'scope looks pretty much the same.  Pin #3 is putting out 1V signals and pin #2 is putting out 3V signals.  I changed the dwell to 3 seconds at each end of the run in the program so I would have plenty of time to see what is happening.  Hmm. Weird stuff again.  The trigger is set to the step signal, otherwise the scope just stares at you on the return direction.  I'll post a couple of pictures.  The timing between the direction and step pulses is varying during the move!  It often starts out with one timing orientation and then just changes...  Also, On the way back, where there is no Direction signal, I've noticed a “twitch” just before the end of the move.  It seems to be a little early for it to be related to the deceleration, but it occurs only on the way back. 
   The upper trace is the step signal, lower trace is the direction signal.  Note that the 1st and 3rd steps seem to be simultaneous  with the direction pulses but the 2nd and 4th are leading or lagging.  The step traces are not moving on the screen, the Direction pulses are moving earlier and later.  Photos are on next post due to the forum software not cooperating...

Don