Messages

11

General Mach Discussion / Re: Kernal Speed and Chatter

« on: September 13, 2009, 04:35:45 PM »

OK, I'm not workin today but I'll give it a go tomorrow.

12

General Mach Discussion / Re: Kernal Speed and Chatter

« on: September 13, 2009, 03:53:45 PM »

Hey Ray,

Thanks for chiming in.

Perhaps I could have been more clear.  In my previous post, I was using accel being set to high as an example of how chatter could occur.

Of course software can not compensate for incorrect settings.  However, it has been my experience when Mach is runing in CV, the speed blending which occurs to create the 'Constant' somehow overides the acel parameters in tuning in its attempt to run every axis at the same speed.  This causes undesirable effects.

Yes- I could adapt my machine so that the Axis were more similar in terms of the tuning profile but, it sure would be nice (read easier) to have some more control over CV (maybe like a CV axis scalling factor) to help smooth things out.

Sid

13

General Mach Discussion / Re: Kernal Speed and Chatter

« on: September 13, 2009, 03:30:50 PM »

VMAX-

Respectfully, I have to disagree.

If you have a machine with a lot of mass and the accel rate is set too high then a rapid acel will cause your machine to jerk, then this will result in what I am interpreting as chatter.  Perhaps I am mistaken or using the incorrect terminology.  If so, I apologize in advance.

While what you say is partially true because the "chatter" it is due to the mass limitations of the machine, the software allows us to slow down our accels to a point where things become smooth.

CV takes this away from us to a certain extent because Mach now want to control velocity on it's own terms (well sort of) but we certainally do not have the same speed/accel control as in exact stop mode.  If 2 or more of your axis are dissimilar in terms of their tuning profile, you will see Mach slowing down one axis a lot more rapidily than the other in an attempt to keep things "Constant"  this struggle can result is Jerky motion (exactly what CV is supposed to prevent).  CV is a double edged sword under these circumstances.

Sid

14

General Mach Discussion / Re: Kernal Speed and Chatter

« on: September 13, 2009, 12:05:36 PM »

Just for 'Grins'- perhaps you can try to cut in Exact Stop mode and see if you are able to reach your 300 IPM target and NOT get the chatter?  This eliminates the chatter for me but changes my cut in an undesireable way so I am kinda locked into using CV.

15

General Mach Discussion / Re: Kernal Speed and Chatter

« on: September 13, 2009, 12:58:22 AM »

My Opinion... this is a CV Issue.  I have been noticing the same issues with a large Foam Band saw I recently built.  I have tried playing around with the CV settings but optimize this but IMHO, due to the fact that the machine is large and has a lot of mass (therfore really slow accels) there is a large speed differential between my X & Y axis (X is belt driven & Y is lead screws) there is simply not enough ability to equalize the CV in order to compensate for one axis being so much slower.

I wish some one had an answer to this.  Just my $.02

Sid

16

General Mach Discussion / Re: E-STOP Mechatronics Controller

« on: September 08, 2009, 12:32:07 AM »

Hood my good man!  Thanks for jumping in! 

Why would you expect to see Active High on an E-Stop which is NC?  Maybe I am confused?  In my mind NC means signal is constantly passing through the switch right?  Thus Signal (High) is constantly being fed to the BOB which should be in a NON Active state UNTILL the ESTOP is pressed, breaks the signal loop, goes LOW which in turn would trigger the Reset.  To me this means Estop is active when there is NO PRESENCE of signal (Active Low) Or am I missing something here?

17

General Mach Discussion / Re: E-STOP Mechatronics Controller

« on: September 07, 2009, 12:37:39 PM »

Well, I gotta say this is becoming a 'stumper'...

1.  Estop button triggers a reset but does not light up the LED on the Diagnostic Screen=Not Normal.  This is really troubling because you should always be able to see an ON SCREEN LED when a switch is triggered.  Do you have any other buttons/switched you can connect to your BOB to see if you can get a LED to light up on this screen?
2.  Estop Button does not maintain the Estop signal to the BOB/computer and allows you to reset eventhough it is engaged=Not Normal
3.  Estop button seems to be functioning normally
4.  Seems Like Mach is configured and functioning OK with every other than E-stop

It points to Hardware/wiring

A. Bad BOB Hardware
B. Bad PP Cable from Computer to BOB do you have another cable you can try?


Sorry but...I'm startin to run out of ideas- I'll keep thinking though

18

General Mach Discussion / Re: E-STOP Mechatronics Controller

« on: September 07, 2009, 11:50:24 AM »

I looked at tthe XML and it looks OK.  Ot this point, basecd on your last post, I'm thinking there is something 'Funkaroo' with your E-Stop Button.  Do you have an OhmMeter?  Can you check the Button (with the power off) to give us a better idea of what's going on there?

We are looking for continuity between 2 terminals on your button UNTILL it is pressed (maintained) then it should be open.

19

General Mach Discussion / Re: E-STOP Mechatronics Controller

« on: September 06, 2009, 01:27:06 PM »

Can you please post your XML file

20

General Mach Discussion / Re: E-STOP Mechatronics Controller

« on: September 05, 2009, 09:59:38 PM »

Hey Now!  Let's not get down & discouraged!  

I think your problem is that you are using Pin 17 for your Router.  Usually Pin 17 is reserved for the charge pump signal.  Try putting your router on Pin 16.

IMO- this is not entirely a Mach 3 config problem.  The Mechatronics controller manual is not very clear/thorough in explaining how to wire up your system, so you are left to guess.  Not really your/Mach's fault.  Mach is designed to be used with a myriad of controllers/BOBs and is flexible enough (configuration wise) do deal with most of them (including yours).

Bottom line..."Easy-Cnc.com" ISN'T very easy

HTH,
Sid