Hello Guest it is October 19, 2019, 06:25:37 AM

Author Topic: Smooth Stepper reset  (Read 8532 times)

0 Members and 1 Guest are viewing this topic.

Offline Jeff_Birt

*
  •  1,107 1,107
    • View Profile
    • Soigeneris
Re: Smooth Stepper reset
« Reply #10 on: August 23, 2009, 10:25:55 AM »
Quote
Is all that info that you just mentioned included in the smoothstepper instructions or something like that something "everyone" should already know?


There is a note somewhere in the docs about it. It is a reset for the flash memory, it clears the flash memory. You have to have the reset shorted when powering on to make it work. As I mentioned you should never need to use it. Usually memory resets like that are intended to rescue a unit (any device with flash memory) that has locked itself into an unknown state.


Quote
I would think if noise was enough to stop the unit, there would be some sort of filter built into the line itself on the smoothstepper?

The problem is noise induced on the USB cable.  The way USB hubs work is that they will give up if they see too much noise. While the SS does have some noise filtering built into it, as does your PC, when building a machine you have to try to minimize the noise from outside sources as much as possible. To do that you need to filter the noise as close to the source as possible, hence I mounted my line filter for the Taig spindle motor in spindle switch box (used a larger box.)
Happy machining , Jeff Birt
 
Re: Smooth Stepper reset
« Reply #11 on: August 23, 2009, 11:33:21 AM »
Jeff,

Thanks for your comments.  It seems that you & I are living parrallel lives regarding the SS.  

I have experienced all of the USB noise related problems that you mention.  

Currently I am having a problem with my spindle motor triggeriing a reset.  Noise filters in the plug in are ineffective.  I'm going to check out the line filter you mentioned but, sometimes it's pretty hard to route the USB cable in the manner in which you describe.  Enclosure size/configuration can make it a real challenge to kick this USB noise thing.  

That being said is is possible to design/build/modify a USB calble that has some sheilding (I don't think USB cables have any??).  Perhaps this might be the 'Silver Bullet'?

Sid

P.S.  Do you guys think we should move this topic over to the SS forum/section???

Offline Jeff_Birt

*
  •  1,107 1,107
    • View Profile
    • Soigeneris
Re: Smooth Stepper reset
« Reply #12 on: August 23, 2009, 11:51:13 AM »
All USB cables (any one that displays a USB logo) is shielded, but it is not enough in all applications.You can try adding a ferrite core over the USB cable, that can help but it can also slew the data making it harder to read. You can also buy shield braid that slips over existing cables. I used to use it all the time on plasma torch leads. Greg is working on an inexpensive USB isolator right now. I think it will be a big hit with all sorts of industrial USB applications.

For spindle motor noise you need to nip-it-in-the-bud by placing a line filer close to your spindle motor. The 10A line filter kit is here: http://soigeneris.com/cncparts2.aspx, I've attached a pic of how I installed it on my Taig.
« Last Edit: August 23, 2009, 11:54:35 AM by Jeff_Birt »
Happy machining , Jeff Birt
 
Re: Smooth Stepper reset
« Reply #13 on: August 23, 2009, 11:53:52 AM »
Hi Jeff,

Is all that info that you just mentioned included in the smoothstepper instructions or something like that something "everyone" should already know?

I would think if noise was enough to stop the unit, there would be some sort of filter built into the line itself on the smoothstepper? Kind of like how they used the filter on a PC monitor cable?

Thanks,
Dave

Dave,

USB 2.0 runs at a 480MBit/sec data rate.  Any "filter" to remove external noise would also remove the signal.  Interfaces like USB simply can't work in noisy environments.  So, you have to fix the noise at the source.  Of course, that's *always* the best way to deal with noise problems anyway.

Regards,
Ray L.
Regards,
Ray L.
Re: Smooth Stepper reset
« Reply #14 on: August 23, 2009, 11:58:47 AM »
Jeff,

Thanks for your comments.  It seems that you & I are living parrallel lives regarding the SS. 

I have experienced all of the USB noise related problems that you mention. 

Currently I am having a problem with my spindle motor triggeriing a reset.  Noise filters in the plug in are ineffective.  I'm going to check out the line filter you mentioned but, sometimes it's pretty hard to route the USB cable in the manner in which you describe.  Enclosure size/configuration can make it a real challenge to kick this USB noise thing. 

That being said is is possible to design/build/modify a USB calble that has some sheilding (I don't think USB cables have any??).  Perhaps this might be the 'Silver Bullet'?

Sid

P.S.  Do you guys think we should move this topic over to the SS forum/section???

Where do you guys have your SS mounted?  I used to have mine mounted *inside* the PC case, and it worked perfectly in there, in two different PCs.  I now have it mounted inside my E-box, which contains *everything* - PC, servo power supplies, VFD, relays, and lots of other stuff.  And the SS is within inches of the servo motor wiring.  It works absolutely perfectly in there.  If you're seeing flaky SS operation, you must have something in your system that is radiating some serious noise.  You should find that, and fix it at the source, and your whole system will probably behave better.  It is very important to have your grounding right.  I think this is an area many people don't understand, and don't handle correctly, ending up with shields that carry signals or noise, ground loops, and other things that can cause very erratic behavior.

Regards,
Ray L.
Regards,
Ray L.
Re: Smooth Stepper reset
« Reply #15 on: August 23, 2009, 12:33:43 PM »
Jeff,

Thanks but, I am running a 1.5HP 3Phase spindel motor from a VFD.  I don't think your line filter is gonna do it for me.  I'll have to search elsewhere.  BTW- I think it's the VFD causing the noise problems in my case-not the motor.

Ray,

I have 2 enclosures.  The main panel is a 36"x24" with most everything in there- Power Distro, Servo Motors/breakouts, E-stop circuit contactors, DC power supplies, circuit protection, the PMDX122 breakout AND finally the SS.  The other enclosure is a 16x20 that is mounted on top of the main panel. It houses the computer, Screen, E-stop button and a few indicator lights.

Everything works pretty well- EXCEPT starting the spindle motor from Mach triggers a reset about 80% of the time.

I don't understand why you would mount the SS inside the PC case.  It seems to me that it defeats the purpose of being able to use USB cables to break the 6' PP cable liimit-maybe I'm misunderstanding something??

I know I'm going to sound like a broken record here but...Interestingly when I run this system on PP everything works flawlessly.  ZERO noise problems.  I just have to run at a lower resolution and conversely a slower speed due to the high encoder count (or use electronic gearing).

Any suggestions to 'get er done' with the SS would be appreciated!!

Thanks,
Sid

Offline Jeff_Birt

*
  •  1,107 1,107
    • View Profile
    • Soigeneris
Re: Smooth Stepper reset
« Reply #16 on: August 23, 2009, 12:50:48 PM »
The noise is there when running with the LPT as well. It is just being picked up by the USB cable. Look to see if your VFD manufacturer has a 'line reactor' available.
Happy machining , Jeff Birt
 
Re: Smooth Stepper reset
« Reply #17 on: August 23, 2009, 01:02:33 PM »
Sid,

Inside the PC enclosure is fairly "quiet", so it's a very safe place to mount the SS.  Inside your "main panel"....  Not so much.  The PP cables are reasonably noise-immine, as long as you use a good shielded cable, and don't connect the shield at the main panel end.  If you want to brute force it, enclose the SS in a metla box.  Just a grounded sheet-metal enclosure (preferably steel) over it should help a lot.  Make sure the USB cable *inside* the "main panel" is as short as possible, and that the main panel itself is well grounded.

MOST problems I see on the forums are due to inadequate shielding and grounding, not SS, not PC, etc.

Regards,
Ray L.
Regards,
Ray L.

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: Smooth Stepper reset
« Reply #18 on: August 23, 2009, 01:07:35 PM »
I think you fellas are correct in saying that most problems are indeed noise. Even though there are MANY variations/ways to put together a CNC setup, there should be a single place that someone can read (and understand, lol!) how to properly ground/sheild a system.

Thanks for the info as always, guys- :)
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)
Re: Smooth Stepper reset
« Reply #19 on: August 23, 2009, 01:45:05 PM »
Ray,

Thanks- Steel Box comming right up!  I know the Main Enclosure is grounded well.  I am using the standard USB cable that Greg/Stephanie ship with their units, I think it's about 4 feet.  It's too short for me to route around the perimeter of the enclosure (away from other pwr cables) SO- I was able to route it BEHIND the subpanel.  It is the only cable runing back there and my thought was that being behind a 1/32" plate of steel it would help with the noise issue. Maybe not??  I'll try the steel box but maybe I need to rething my USB cable routing and get a longer USB-A to USB-B?

Aside from this issue- everything else works good!

Regards,
Sid