Lost connection, how to avoid?

[lto]

we have recently cut a new vacuum grid into mdf. We had several instances of lost communication, which hasn't been much of a problem over the last months. It seems to happen more readily while cutting mdf, and while the shop has a low relative humidity. This is on a PRT Alpha, where we have grounded the dust hose, etc. What is the best way to eliminate this issue? Is anyone using a line conditioner successfully? Any other ideas?

[Brady Watson]

Louis,
It seems to me that you are having a static electricity issue. The best way I have found to ground the DC hose is to run a bare copper wire all the way through the INSIDE of the hose, and poke it out of the ends. Then tie the end to ground on the DC chassis. The coiled wire inside of most hoses really doesn't wick up the static like a bare wire.

To make it easy, just wad some masking tape into a ball and wrap the wire around it. Let the DC pull the wire thru the hose, but be careful that you don't let the wire make it into the DC itself, or you'll have a mess on your hands!

-B

[lto]

Thanks Brady,
We grounded the dust hose as suggested. So far all's well.

[rcnewcomb]

We had a similar issue when we first set up the bot. Brady is right, static electricity seemed to be the root cause. We grounded absolutely everything and made sure our wire runs were clean and organized. On the rare occasion that we have communication errors return it means it is time to recheck the grounding.

[nat_wheatley]

What additional steps can I take to reduce static? I've grounded my dust hose as Brady has described, and run a ground from the leg of the Bot to the electrical service, but am still having issues.

I touched up against one of the rails today, which seemed triggered an error, which would lead me to believe that static is still an issue. I use a shopvac to clean the table which does seems to produce quite a bit.

[Gary Campbell]

Louis, Nat...
Here is an article I wrote for the SB Wiki a year ago on how I grounded our machine: http://shopbotwiki.com/index.php?title=Grounding_your_ShopBot

It does make a difference!
Gary

[nat_wheatley]

Extremely helpful, thanks Gary.