Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Snfrwly on October 28, 2014, 04:30:14 AM
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Hi Everyone,
Recently got a new CNC machine (one of those Chinese Routers) Have it set up, running Gcode. I am using Mach3 and UC100 USB for the connection. It's generally smooth and fast, but seems to have random connection problems when running code? I am getting 'UC100 Connection lost', sometimes 2 or 3 times per code run. CNC comp is a decent WinXP laptop which I have been previously using to run my CNC hotwire (also with Mach3 / UC100). I have been checking the threads for similar problems, but most people seem to have other issues just getting the machines to run. This one can run code perfectly, but will randomly lose connection. Any ideas?
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I have 2 UC-100s and 2 UC-300s. They are all on standard motherboards and I've never had that problem. My guess is the laptop is probably turning off power to the usb to save energy. There are settings in the device manager to keep the power on at all times to the USB bus
Derek
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Hi Derek,
Will give it a shot. I don't think I ever had this problem with my CNC hotwire, but I rarely ran a toolpath more than 10mins or so, and I was usually standing nearby, fiddling with the comp. I have turned off that USB power management and will let you know how it goes!
-Sean
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Well, that was short lived optimism.
Changed the USB power management settings, rebooted everything, and got a UC100 disconnection 2 mins into running a toolpath. I've attached a picture of my machine, as its one of those Chinese routers a lot of people have problems with. There seems to be zero regularity to the problem so I'm not sure if it's computer related. The frustrating aspet of this is I have another CNC comp with parallel port (so I can skip UC100), but with identical Mach3 settings, the machine is jerky and missing steps.
(http://i.imgur.com/xFcHvXl.jpg)
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It may be the USB cable. In another forum, the problem of frequently losing connection with the computer was found to be external noise from overhead light fixture, and a high quality USB cable with double shielding was the solution. They had a video that showed the action with two types of cable, and switching the light fixture on and off.
Also, many have found that the Ethernet connection to be far more reliable than the USB, in the controllers that make both types, like the Smooth Stepper.
Noise problems can be very elusive, but have been one of the most frequent problems on the Mach3 forum.
John
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Hi John,
I did a quick experiment to test the noise hypothesis.
Current Setup:
USB cable to UC100, parallel cable to CNC controller. The UC 100 was about 1m away from the box, and I would get random disconnections, but sometimes would be ok for 20-30mins of mill time.
Experimental Setup:
USB cable to UC100, UC100 plugged directly into the CNC controller box. This resulted in instant disconnection when the spindle was turned on!
So I think it's pretty clear there's a noise problem, and now I can go about fixing it:
-moving UC100 far away from the CNC controller.
-adding a shielded USB cable.
-replacing power supply for controller.
The last item is a bit of a pain, but the machine should run better with a SMPS instead of the giant step-down coil that's in there right now. Would also radically reduce noise.
-Sean
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Keep in mind if you have that kind of noise it's not the fault of the UC-100. So moving it is just a kludge. That kind of noise will affect the rest of the electronics in small ways. You should be able to plug the UC-100 into the BOB and run a decent USB cable to the computer without issues. I have 2 setups like that and no issues. I would use the UC-100 at this point as a "canary in a coal mine" and get the noise under control.
Just my 2 cents.
Derek
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Here is a detailed look at how to ground electronics, by Randy at Texas Microcircuits. Although it is for a Plasma table, the principles apply to all electronics.
http://www.texasmicrocircuits.com/RF_info.html
John
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Just thought I'd chime in again with the fix (as suggested!) was the Cable. Swapped out the USB for a double shielded USB cable with ferrite bead. Haven't had a single disconnection since!
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Hi Snfrwly:
Always nice to hear a suggestion helped, and problem solved. Thanks for posting.
John
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Howdy, more of the same
I observe erratic connection losses between a UC300 and a Win 7 (32bits) laptop box running Mach 3. No power RF sources around, simply 3 axis actuated by NEMA 24 steppers.
Motor cables shielded with braid and separated from limit / home cabling which run in their own shielded braid. Single point grounding to avoid ground loops.
Connection losses do not seem to be influenced by machine activity, or the lack thereof.
I could be in IDLE state for an hour, or work for 30 minutes without any connection loss or be idle for 2 minutes and experience 5 connection losses in a row.
I do not seem to be able to find any pattern. Hard to say if it is Mach 3 / the Win 7 box / or the UC300 motion driver. Tested several USB cables and double checked for ground loops.
Any hint is welcome,
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I have also problems with UC100 sync errors.... but I think the problem is my USB RS485 dongle?
if I run my machine , and I change the speed of my spindel with the buttons on the VFD, I have no problems...
Change I the speed via the USB RS485 dongle I have UC100 sync errors al the time?
if I push the up or down speed button in Mach3, the blue led goes off... and I see that the buffer in the plugin UC100 screen goes empty....?
https://www.youtube.com/watch?v=Ur4_iC8LQ2g&feature=youtu.be
I think I go try a other USB-RS485?
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Any news Swets how u overcome the problem?
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Hi just my two bobs worth, replace the usb cable that came with uc100, I had problems with the cable, it was actually loose fit and vibrations on the machine caused problems, bought a new cable and never had that problem again that was two years ago still going good. ( touch wood!) ;D
Nick
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No, still have the problem... I have al ready a beter usb cable... with a ferrietcore and I have a couple of this: https://www.ebay.com/p/Ferrite-Core-Yamay-10pack-Snap-on-7mm-Ferrite-Core-Cord-Ring-Choke-Bead-RFI/2009492176?iid=282419335119
still not found the problem....
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When I was having problems with my UC100, I tried many things being described; power saving modes, new cable, re-routing usb cable, etc.
The last thing I did was add a powered USB hub between the computer and the UC100. Since then, I have much better success. I will say, if I had to do it all over again, I would go the ethernet way and avoid USB - seems like a lot of people have trouble with it.
Chris D
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yes me to.... I have the UC100 because it is the same as the LPT, so I don't need a other BOB... and don't have to change the wiring....
and I have now a PC without a printerpoort... so I can't back.... stil have problems....
and only if I send a command with the rs485...
I orde a other rs485... maybe that helps...???
I go try the other VFD-plugin .... maybe that helps? later more.....