Motors not moving

[Mike Windsor]

I haven't used my bot in quite a while , but have a mysterious problem .It's a PR machine using a PRT control box with the latest version of the SB software . About two minutes into a cut file the machine stopped moving . The position on the display kept going though . I stopped the machine and re-booted the control box . Re-homed everything and started again . The machine went a bit further into the file than before , but stopped moving again , and the display kept on going like I was in preview mode . ----Any ideas ? ---I thought about the power supply but would it act up intermittently ? Thanks Mike

[Brady Watson]

Mike,
What is the speed of your computer? Did you get any communication errors? (error box says 'COM error')

-Brady

[Mike Windsor]

The computer is a 1 ghz running windows 98 . I've used it with the bot for the last couple of years with no problems . ---No Comm errors . I raced the carriage arround at 6 IPM for about half an hour , and couldn't get it to stop . I re-tried cutting the file four more times . Each time it would get a bit further than before , but it seems to be when the PC router is under load that the problem happens . I even ran it with a volt meter hooked on to the 44 volt power supply . When the motors stopped moving , the position indicators on the screen kept moving like it was cutting , and I still had 44 volts going to the board . The only part that seems to be repeatable is the problem happens when the Porter Cable router starts running under load . ---- I have a copper ground wire running through my dust collection hose and everything is Grounded . Thanks Mike

[stevem]

Mike, do you have the router connected to the same circuit as the computer?

[burchbot]

Hi Mike
Are you running that program from a floppy disk? I had a problem like that, It would stop in the cut..It turned out to be the floppy drive.
Dan

[Mike Windsor]

The computer , the control box and the router are all on the same circut , and have been for a couple of years , and haven't been a problem before . The shopbot computer is hooked up to my design computer with a cat 5 network cable . I haven't used a floppy disk for some time . I think that my next move is going to be swapping out the router for my spare . ----Is it possible that some weird signal or some electrical short is being sent from the router via the ground connection of the router body back to the control box ?

[patricktoomey]

Mike,

It is very possible that the setup has worked in the past but now something subtle has changed in one of the devices. The router could be emitting more electro magnetic noise back into the power line due to things like brush wear. The computer's power supply could also be breaking down slightly since many electronic components like capacitors change slightly with age. The power supply could now be more sensitive than it was before. Separating the computer and router onto separate circuits would be a good start. Changing the router out has a chance of working too. If you search these forums for terms like eltrical noise or emi filters you should find some threads on some filters that may help as well. Here is a link to one, look about 2/3rds of the way down the page for some filters... http://www.talkshopbot.com/forum/messages/27/6761.html

Good luck

[larry_r]

I would suggest running your progarm with the router unplugged and do an air cut. If that does not solve the problem, then unplug the network cable and repeat above.Good Luck.

[paul_z]

Mike,

I bought a UPS for my control computer. I think it was $34 at Walmart. It is rated 250W for 10 minutes. (I just need it to provide 150W for a few seconds.) I didn't load the "feed back" software so I don't know if or how many times it "kicks in".

Paul Z

[Mike Windsor]

Thanks to everybody for all the suggestions . ---Murphy's second Law --" If you fix something long enough you'll eventualy bust it " --- Anyway after trying different outlets for the router and power supply , running the bot with my laptop , changing routers , and even the brushes in the router , I started to think about what is different from when this last worked ? ----For years I used a vacuum hose from a central vac system ( about 1 1/2" diameter ) a few months ago I changed it to a 2 1/2" real dust colector hose . While I was at it I thought to myself " I really should ground this ( which I hadn't before ) I use one of those cyclone lids for a trash can and a 5 hp shop vac . I ran a stranded bare copper wire through the hose from the router all the way to the cyclone lid where I ran it out and grounded it to the frame of the bot . The thing that was mystifying me was that everything worked fine until The router started making dust . ---That's when I spotted the electrickery happening around the lid of the cyclone seperator where the wire was coming out . ---Sparks about 1/2 an inch long ! ----So I re-routed the wire so that it goes all the way though the hose to the shop vac , and from there out to an electrical ground . ---So far I've been cutting for an hour with no problems .

[Brady Watson]

Yep...Static electrickery will definately cause that!!! And it will also FRY your PRT board if you have a hot enough spark! Glad you caught it in time!

-Brady