Shopbot just quits!!

[myxpykalix]

I ran a grounding wire for my dust control but for some reason just on one file (a simple square) the bot tanked out on mre 4 times. It would just stop and the error message would come up (lost communication with control) and i would have to rezero everything because it lost all settings. If for some reason i don't have my grounding setup right, is it reasonable to think that the static would knock it out 4 times for one file? While doing a previous file before this one it stopped 3 times. So its not the specific file, asd it has done it on many others at different times. I'm using ver 3.4.27 is there a problem with this version?

[Brady Watson]

Yes, it is reasonable to think that static will cause disconnects.

The only surefire way to eliminate the static problem is to run a bare copper wire through the dust hose and connect it to ground on the dust collector. The bare wire will wick up any static in the hose and give it a straight path to ground.

I have witnessed improperly grounded dust collection systems fry electronics on PRTs. Alpha control boxes seem to be robust enough to handle static charges, but this is at the expense of communication loss. If you ground the system properly it should no longer be an issue.

-B

[myxpykalix]

Just run it through the pipe (as i did) but ground it directly to the housing on my dust collector? Will that be sufficient? thanks

[conceptmachine]

Jack
I grounded my dust collector directly to the ground on the motor and have had no problems.
shawn

[nappy1]

Yes. You want the static discharge to go through the ground on the dust collector, not the controller cabinet.

[fleinbach]

When running a ground wire through your vacuum hose you should ground both ends. You could get away with grounding just one end but the preferred method is to ground both. Also, if you're not to familiar with wire you should be running a braided wire not solid copper. A braided copper wire will tolerate flexing hundreds of times more than a solid copper wire.

Another alternative is to purchase a vacuum hose that is wire wound. I purchased mine from woodcraft, but I just went to their site and even though they show it they say they no longer carry it. Here is a place that carries a variety of them. http://www.domainelectric.com/us/1862/Kitchen/552656/Top%2020%20-%20Hoses/

[GlenP]

I have mine grounded at one end and connected to the pipe on the other. If you ground both ends you will create a complete circuit and it may loop instead of draining. I also used an oversized wire for ground and grounded the pipes in several locations on the piping system. The braided wire Frank talks about is a good idea. I would also ground as close to the dust pipe on the bot as possible. Just my 2 cdn cents. Very cold here this morning (-20).

[ed_lang]

Jack,
Take your dust skirt off and run the file without dust collection and see if it does the same thing. I have a feeling it will. I bet the laptop you are using has a bunch of "other" software on it now and you just might be running into a problem with the computer not giving the ShopBot full attention.

When you wired up the machine, did you run a ground from the service ground to the frame? Did you remove the paint behind any ground wires or straps? Did you use a toothed or star washer between the ground wire/strap and the machine?

If anyone does not think that static can build up to a very high voltage in a dust collection system, take a look at this picture;
http://kc4ylx.smugmug.com/gallery/1279086#60077085
This is my ClearVue Cyclone before I ran ground wires. I was running my 20inch planer and heard a loud crack and saw a blue light over in the dark corner where the cyclone is mounted. I went over and saw the results of the static discharge. Then I took pictures and grounded the system. What you are looking at is the dust blown away from the surface of the cyclone body when the discharge took place.

After grounding the system and running a ground wire around the outside of the PVC duct, I have had no further discharges that were detectable by me. Also when you walk next to the flex hoses now it does not pull your hair up!

[harryball]

As I post this I doom myself to problems today :-)

During installation before even powering up I drilled a hold in the concrete and drove an 8' grounding rod for my bot. I connected the frame of the bot directly to the ground AND the power grounding rod to the ground (no chance of grounding through the bot that way).

Of course my dust collection system is grounded as well.

Robert

[elcruisr]

Remember that all those wires that run from motors, zero plate, etc are also great antennas! When all our grounding problems were solved we still had a few com breaks. These were solved with ferrite chokes on all motor, control and prox switch wires.

[paco]

That's interesting. Apart from some electrical static discharge from vacuuming around the tool and grounding myself on the tool frame, I have attributed most of my disconnect to SB3 and my control PC interaction. I do am aware that I need a very optimized PC and believe mine is...

Eric, do you disagree with the above? Were you thinking like me and then decide to try the ferrite on the sensitive wires?
Can you provide me (us) with the ferrite details; model, installation...

Thanks in advance.

[jseiler]

ed,

You might find this interesting...

http://en.wikipedia.org/wiki/Lichtenberg_figure

[elcruisr]

We had been through better machine grounds, dust collection grounds, computer issues, etc. Each one made things better but never completely solved all the issues. We'd still get a com break every other day or so. We had and electronics engineer in the shop who suggested trying ferrite chokes on our peripheral wires to eliminate RF "Noise". These are just ferrite loops about 1.25" in diameter. Wires are wrapped around and through three times and done near the control box. They are available from most electronics supply houses like Mouser Electronics. I can probably find a supplier if anyone needs some to try, I remember them being pretty cheap.

Since installing them a few years ago we have very rarely had any com breaks!

[paco]

quote:Wires are wrapped around and through three times and done near the control box.
That would be for each wires; 1 wire = 1 ferrite?
Only near the control box?

[geneb]

Another thing to look out for is noise created by the 3 phase power for a spindle. Until I installed a USB 2.0 powered HUB, I was _constantly_ getting comm failures when the spindle was running. If the comms died during warm-up, I knew the day was going to suck. *sigh*

So far, so good on the powered hub though.

Having a 10 foot, poorly shielded USB cable doesn't help either.

g.

[elcruisr]

>>That would be for each wires; 1 wire = 1 ferrite?
Only near the control box?<<

Correct!

Gene, a ferrite will cancel out alot of the noise your USB cable is picking up as well.

The engineer stated that a ferrite at each end is the ultimate but on some cables that wasn't possible. On checking my setup I found that we only used them on all the input cables such as the z plate, limit switches, stop switch and the network cable. It sure helped though!

[paco]

Hummm... so no ferrite on the motors cables?... I already have filter on my limit switches input and I believe I have one on the E-stop too. It doesn't really make sense, to me, to have anything on the other input signal unless they're being monitored by SB3; my Z-plate regularly ground while the Bot cut (I can see the input lighting up) and since the input isn't monitored for any event, it never bothered the signal.

I was more concerned about the motor cable and maybe the USB (control PC to control box). I have no network connected to my control PC and the USB to control box is about 3 feet away...

Most of disconnect I have are while I run custom cuts or when I'm in Keyboard mode.

[jsfrost]

A ferrite minimizes RF flowing on a wire by converting the RF energy to heat at the point where the ferrite is placed. The wire is still able to pick up interferance at distances away from the ferrite, so the best location for a single ferrite is as close as possible to the circuit being protected. In high power transmitters, we often string multiple ferites along the wiring, and call them prayer beads.

My disconnects typically occur shortly after turn on., and only rarely. I still wonder why.

[elcruisr]

Problem is each situation is often unique to the installed location of our equipment. It's possible to have "noisy" power coming in. RF noise coming in through a ground system. Noise from other equipment in the shop, neighbors, etc. Even the boys with the big iron deal with similar headaches. I've talked to one CNC tech whose been battling something similar on a very expensive machine for over a year. Everything will check out perfect while he's there but a few days later the mysterious stops will emerge again.

Ain't technology fun?

Paco, all those peripherals are sharing a common ground though. Don't know why that should be an issue but maybe?

[geneb]

Eric, I'd already done the ferrite trick. I'm a Ham. That kind of thing comes naturally.


It would be nice if SB would include an A-A cable with ferrite cores cast on each end though.

73 de kc7afe
g.

[myxpykalix]

Just a followup to my original problem in this post. I ran a bare copper wire from the carriage end of the dust collector pipe to the dust collector, ran the wire out of the pipe and grounded it to the dust collector and I haven't had a shutdown yet....As usual "you know who" was right again....(Brady) thanks