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Author Topic: Problems threading on the lathe  (Read 330258 times)

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Offline Hood

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Re: Problems threading on the lathe
« Reply #360 on: May 25, 2009, 05:27:13 PM »
VFD always running when it craps out?
 Tried a different USB Cable?
 Tried grounding the SS? I have never needed to do it but think I remember seeing a few on the Warp forum that had to.
Hood
Re: Problems threading on the lathe
« Reply #361 on: May 25, 2009, 05:31:22 PM »
tried a diff USB cable , no change

doesnt matter if vfd is on or not

will ground SS in just a minute
Re: Problems threading on the lathe
« Reply #362 on: May 25, 2009, 06:14:45 PM »
back to the original screen set , VFD not even powered up and still losing SS after 5 minutes or so

Also notice a couple of tools in the library lose there z axis offset value every 3rd or 4th time I get a freeze  ???
« Last Edit: May 25, 2009, 06:16:54 PM by panaceabeachbum »
Re: Problems threading on the lathe
« Reply #363 on: May 25, 2009, 10:24:45 PM »
I put the borrowed computer and smooth stepper back in the milling machine and now that I have updated it to the latest version of Mach and the latest SS plugin it now loses communication with the ss about every 5 minutes just like the lathe. I have never had this problem with this machine which often stays plugged in and on for days at a time . Considering its doing the same thing now that the software has been updated as the lathe that the issue must be software related. I am pretty sure I have eliminated all the other variables by swapping SS, cables, mouse keyboards, machine, computers, full format and reload on two diff computers etc and now the problem exist on two diff machines.
Re: Problems threading on the lathe
« Reply #364 on: May 26, 2009, 02:25:35 AM »
Hi Richard,

Sorry to hear about all of the trouble you've been having.  It is strange how USB works flawlessly for some and not for others.  Thanks Hood for your determination in getting to the bottom of this one.

I would guess that you would have the best luck shortening the USB cable as short as you can (6 inches if possible), and then using parallel port cables to go from the SS to the breakout boards.  I can't guarantee it, but I have had users fix USB communications problems that way.  Another possibility is to run a heavy duty ground wire between the SmoothStepper and the computer, in parallel with the USB cable.  I suspect you might have a ground loop present, and while it would be best to eliminate the ground loop, you can minimize it by minimizing the impedance between the computer and the SS.  Another trick that can help is to insert a self-powered hub in between the computer and the SS.  A hub can help regenerate the USB signals and interfere with the ground loop.  It would be interesting to see if you can measure any voltage difference between the ground of the SS and the ground of the PC.  You can also try plugging things into different outlets.  Please let me know if any of this helps.  If it doesn't we'll keep at it.

Thanks,

Greg

Offline lemo

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Re: Problems threading on the lathe
« Reply #365 on: May 26, 2009, 07:18:33 AM »
I have no problems whatsoever and the machine I build runs several hours every day. It's a Servo machine. We have another stepper based machine in production which caused the mentioned problems and they are mostly related to a long USB cable, and significantly related to the NOISE from the stepper's which telegraphs into the rest of the system. It is crucial to shield the heck out of a stepper based system to eliminate interference. SS might have issues but there are no catastrophic outages or failures. Several million lines if g-code have been processed here with speeds between 10ips and 1200ips on systems requiring high step frequencies to achieve that. Any problem related to communication loss or other significant events alike must be related to the setup in our experience. Two issues which bug us a lot are the fact that increasing the feed speed above 100% is not possible and that the CV mode has major issues. We are looking forward to the next version and some Mach3 CV enhancements.
Rainer
Cut five times and still to short...
Re: Problems threading on the lathe
« Reply #366 on: May 26, 2009, 08:43:27 AM »
I will be back on the project all day today , the only thing that bothers me is since updating the software on the second computer the machine it lives at is now losing comm with the SS also making me wonedr if its plugin or software related.
I wouldnt doubt there is a problem with long USB cable on the lathe , its nearly 10 feet from the front of the machine where the computer is located to the control cabinet at the rear and the cable is 12 feet long . I will try running the USB cable in a piece of metal conduit the entire length  along with ground . 
 Another thing that is odd is I loose communication even when the machine is sitting idle with spindle off and no motion .  I am sure it will be a simple fix once figured out .

Offline ART

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Re: Problems threading on the lathe
« Reply #367 on: May 26, 2009, 08:48:56 AM »
Hi:

 Just a note on the "feedrate over 100%" issue. I recommend on SS systems that people post their code at twice to feedrate they desire, and program Mach3 to come up at 50% feedrate at all times.
This allows you to adjust feedrate up to 100% thus doubleing the speed anytime you wish. Setting it back down to 50% would give you the desired feedrate.

  Id do this internally, but the printer port is limited in max speed, and it would waste bandwidth for the printer port where people may want 100% of the kernal speed available all the time. In the case of the SS though, it is so fast that it would be rare to max out its capability. Running at all times normally at 50% and posting at 200% would solve any issue with speed. ( At the cost of being carefull that your at 50% when running normally. )

  Eventually though, this will likely all be done internally thus giving a capability of more than 100% of speed. There are technical issues with just allowing more than 100% as a norm, because the acceleration profiles and such woudl be overrun thus making it accelerate too hard and decelerate too hard.

Art
  

Offline Hood

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Re: Problems threading on the lathe
« Reply #368 on: May 26, 2009, 09:16:18 AM »
Art
 What would happen with threading with regards FRO being 50%, I seem to recall that there were issues previously if FRO was other than 100% and threading was attempted, maybe I am just dreaming though.
 As for SS, Greg has put the FRO back to Mach control in a  Beta plugin I have tested (and still have) on the mill and it works great for me. There was a problem when going below about 10% FRO but that turned out to be a Mach issue and Brian fixed that up and if I remember right it was put into Rev 027. So if/when Greg releases that plugin the issue of FRO should be resolved.
 
 Hood

Offline ART

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Re: Problems threading on the lathe
« Reply #369 on: May 26, 2009, 10:12:37 AM »
Hood:

  Good point, threading woudl be an issue, to thread youd have to set the feedrate properly as the program auto sets to 100% for the threading run..

Art