Doing my head in

[ken_r]

I recently re-set up a PRT Alpha machine with a new computer (XP dual core 1G ram)it also was set up with a 2.2 HSD spindle.
Each time I try to cut a file I get the old "lossing contact with control box".
I also have a vacuum pump and dust extraction working at the same time.
The machine will go through the file if I do an air cut without the spindle on but with the dust extraction and Vac pump turned on. The second I turn the spindle on it stops and gives me the above message.
Now, I thought that it must be noise comming from the spindle BUT I can also run the same file with the spindle and dust extraction on but not the vac pump. The second I turn the vac pump on the machine stops again.
Now it gets a bit weirder, I can plug in my old laptop that has just about everthing on it and is slower than an old mule but can run for hours without a hitch with all appliances running.
I have tried another new computer with XP and heaps of power but it does the same thing as the other desktop.
If it was about electrical noise or grounding I would be happy but if it was about those issues WHY does my old laptop work and not the new computers? (yes I have made sure there is nothing running in the background of the desktops)
any ideas

[gpari]

I say its static caused by insufficient grounding. Had the same problem when I got mine. Laptop worked fine, new desktop lost contact everytime I fired up the spindle. Maybe the laptop has better shielding or RF filters, who knows.

Run a speedtest (in the diagnostic folder) on the USB cable as well.

Good Luck.

[ted]

Hi Ken,

I favor Gabe's ground noise suggestion. Laptops tend to provide a little better isolation from noise that gets in over the system ground.

Sometimes it can be a little wierd to figure out. Try grounding, ungrounding, and regrounding in various ways. Powering the PC from a line on a totally separate circuit may be a good diagnostic test. One of the little ferrite noise filters on the USB cable may help. Or, if you are not already using a USB 2.0 hub, you could try that at both the computer and the tool end of the USB cable.

Ted Hall, ShopBot Tools

[kenakabrowncom]

Let me jump in on this thread as I am having a very similar issue.

New BT48 Alpha with the same spindle.

I have the power for the controller and PC on independent isolated circuits. Nothing shares these circuits.

I can air cut files all day long and also can cut files in foam. But as soon as i try running a file in wood the tool will run for only moments and I then get a comm error.

The PC is a older Dell.. I am using the provided hub and USB cable. I was concerned that static was an issue on the dust system so currently i dont have any of the dust collection parts installed.

The PC has had the wireless card disabled, auto update is off... no virus software and no other software other than acrobat.

Has any one run the bot on a standard serial cable vs trying to do this on USB? I am not convinced that USB provides the best way to do this type of communication. It would require having to put a serial card in the PC but at least I would be cutting something other than foam!

Ken

[sawdust535]

Ken,
As Ted noted above: "Sometimes it can be a little wierd to figure out. Try grounding, ungrounding, and regrounding in various ways"
I experienced similar problems and tried grounding to various locations and finally solved the noise issue.
What are you doing differently when you cut foam as opposed to wood?

[gpari]

Once I solved the grounding issues, I've run my bot on USB cables up to 30' long with no problems. I don't think it's the USB cable. Run a continuous stranded copper wire, starting at the spindle mounting plate, to every moving part of the gantry, then to the table and finally to the building electrical ground. You want to eliminate the ground traveling through the rollers, pinions, or any moving part. Make sure your dust collection hoses are all grounded to the dust collector base, motor and fan housing.

Good luck, it works, Really


Gabe

[kenakabrowncom]

Thanks Gabe and George...

Re/ the diffrence between air cutting, foam and wood? I have thought of that too and there is absolutely nothing that we are doing that is diffrent.

Re/ grounding... I asked the guys at support about that because I had seen a number of threads on this and they said that doing this would have no impact. It's not a big deal to do this but again why would I only have this problem when cutting wood?

[scottbot]

Ken,
I have a PRSalpha with a 4hp HSD. I had a horrible time trying to keep it running when I first set it up. I would get all sorts of random crashes. It went on for about a month.

ShopBot support helped out the best they could and even sent me a new control board which turned out not to be the solution.

I sent a plea for help to the forum and, like you, got a lot of helpful suggestions.
I did the grounding thing but it didn't fix the problem. But it has for others.

I'm not sure what was the actual cure because one day I made a lot of changes and it has worked perfectly ever since.

The changes I made were:
I pulled all the wiring off the machine and separated all the power carrying wires from the signal carrying wires. I use energy chain to run my wires so I put the spindle power wire and the stepper motor wires on one side of the e-chain and the prox switch wires and the spindle fan wire on the other side.

I saw a forum thread where someone had taken all the extra wire and put it together in a box to keep things neat. I had done that too. That included prox wires, e-stop wires and motor wires.
I took all those wires out of the box and separated them and hung them in individual loops on the under side of my table.

I installed a new USB cable to the control box and also a new contact block (the little blue plastic block that the wires go into) for the e-stop.

After that all was good.
One other thing. This one is a little embarrassing. Even though I have a spindle and don't need to use the grounding clamp to perform a z-zero, it came pre-wired with one so I just left it attached to the wiring harness. I used to clamp it to a piece of aluminum angle that I have bolted to the xy car. Turns out that was a bad thing to do. One day I removed it and things worked a LOT better. That didn't cure the problem but it was definitely a contributor. Now I clamp it to the plastic e-chain. No more trouble.

I hope this helps.
Good luck. Don't despair. One day you'll get the right fix and you'll be on your way.

Scott

[kenakabrowncom]

Scott .. after working all day yesterday with Frank in support (5 stars for him) it seems like I am going the same direction. The issue is with proximity switch 2 and the wiring is likely the culprit.

Frank had me disconnect the proximity switches and everything ran great. I then returned the number 2 wire and still had the problem... after putting number 3 on and 2 off the problems stopped.

I now need to go through the wiring and do just as you did and seperate anything with power from the control wires as Frank and I suspect that we are getting 'noise' that is causing this issue. Mean while I have the number 2 switch disabled and we seem to be humming along.

Ken

[scottbot]

That's great Ken.
I know how frustrating it is chasing the gremlin.
It sure is satisfying when you finally get it though.

Once I decided to bite the bullet and re-route the wires it actually went much quicker than I thought it would.

I'm glad you got it worked out.
Frank was a huge help to me as well.

Scott

[kenakabrowncom]

My com errors continue.....

The list of things that I have done with this machine is extensive. Tech support has run out of ideas and I now have a 500# paperweight in my shop.

Hopefully someone has some new suggestions as my next move will be to recrate this 'hardware' and ship it back to North Carolina.

I have done nothing for the past 10 days but diagnose and make changes... Some of the changes have seemed to work.... we get excited that we figured it out only to be sadly disappointed.

The stack of foam board, MDF and expanded PVC scraps is getting very tall....

[scottbot]

Ken,
I fought mine for about a month.
I was seriously unhappy with the Bot because, like you, I would get a fix to work but it would only last for a day or less.

In the end I don't know what fix solved the problem but it's been working without problem ever since. I know it's frustrating but don't give up because when you get it working you're going to love it.

I suspect that a big part of my problem was my own doing because of the way I set things up.

One of the changes I made that you may want to consider if you haven't already done it is to change the USB cable going to the Control Box. Or at the very least route it very carefully to isolate it as best you can. Mine ran across the floor and I wondered if I had damaged it by stepping on it. It's now housed in one of those rubber cable protectors.
It's difficult to totally isolate it from all the other wires but when I had to place it near another wire or cross the path of another wire with the USB I crossed the wire at a 90 degree angle to minimize the opportunity for electrical interference. I even ran the USB over little bridges made from short pieces of 2x4 (still in use) to keep the USB as isolated as possible.
Remember that the USB is THE information highway from the computer to the Bot. Give it all the help you can to deliver clean signals to the Bot.

I hope this helps. Good luck and keep us in the loop.

Scott

[kenakabrowncom]

Thanks for the advise Scott... but, been there, done that.

We tried another USB cable and let it run straight out of the control box to the PC. We let it run out the big door by keeping the door ajar while the system ran. That was one of those 'temporary' solutions.

The big issue right now is that last night it stopped and we now can not connect at all. No matter what we do there is no connecting between either of my PC's and the bot.

I am totally out of ideas.....

[scottbot]

Darn.
I'm running out of ideas too.
Mine too used to have the issue you are now having.
The only way I could get it to work was to leave it sit for a while (hours) and it would mysteriously start to work.

Sorry but I'm stumped now.

Scott

[kenakabrowncom]

I sent a message to support last night and have had an exchange of emails with them today... they are going to send a new control board on Monday.... I am going to say my prayers tonight that this is the problem....

Thanks for everyones support and suggestions!

kb

[andyb]

Ken,
Have you tried the 2.0 USB hub that Ted suggested? I had the same problem on my PRTAlpha. Air cuts would work fine but as soon as I start to do some real cutting I would get the comm errors. I tried everything that I could think of. I even tried 2 separate PCs. As soon as I installed a small $20 2.0 USB hub from Wal-Mart the problem went away. The SB has worked great every since.

Andy B.

[kenakabrowncom]

Thanks for the encouragement Andy.... Yes, I went out on Saturday and bought a Linksys Powered 2.0 USB hub... still no good.

The major problem at this point is that I can not even connect. It seems that there is a real failure at this point... Hopefully the new control board is the solution.

[dubliner]

Can you see a Thumb drive show up when you plug one into the hub?

[ken_r]

I am starting to think there is to much frequency noise caused from the HSD spindles!!!!
I grounded my CPU to the ground bar in the control box and Yee Ha I have conection to my machine without it stopping during a file.
Now a new problem has accured, when it finishes the file it jogs to safe home which is not actually safe home, the X axis and the Z axis are 0.4" and 0.1" away from safe home.
Never have I had this inacuracy problem and still my old laptop does not produce these mistakes.
I had a frustrating day dealing with this problem when a friend of mine who I had recomended a 2.2 HSD rang me.
He too had been having problems with his computer after attaching a 2.2 HSD spindle to it.
He never had a problem with his router stopping files.
He too grounded his CPU to the ground bar in the control box, but in difference to my end result his would start jogging home and his Z axis would keep rising until it went beyond the machine limits, then loose driver contact with the control box.
Very similar problems from two set ups that just recieved 2.2 HSD spindles. Hmmmmmmm

[tkovacs]

For what it is worth I have a 2.2 HSD spindle and have never had a problem. Running with an older laptop thru a cheap USB hub. Maybe I am just lucky!

But... the spindle/contoller does put noise on the power line. I know this because we have X10 controlled spotlights outside the shop and some of them turn on whenever I start the spindle. X10 is a system which controls lights/outlets using signals sent over the power lines. My spindle controller is on a completly separate 220V circuit - maybe that helps.