Shopbot Link looses zero to table after bit change

[Ron Sloan]

Several times, after a bit change in the Shopbot Link, the software looses the Zero to table parameter. Twice, I had it cut into the table. Now I keep a close eye on it, and have to cancel and restart the job when it happens. Doesn't always happen, but way too often to feel comfortable trusting it! When it happens, I can see the change in the Z setting in the Shopbot Control Software.
Any ideas?

Thanks and best regards,
Ron

[Donald Thomson]

There is something wrong between Shopbot Control and your CNC. I've been using SBLink for 9 years and have never had it do what you are explaining and I cut close to a thousand sheets of plywood a year.

Not sure what is happening but sounds like the machine might be losing comms with the controller or the computer. Do you have REALLY good grounding setup for the machine? Shopbot has an entire article on good grounding of the machine. Before I grounded mine properly, I was having intermittent comms problems, especially when the dust collector was running, creating a lot of static.

[Nat Wheatley]

I'm with Don on this one, as I've not had that happen.

I had years of comm errors, causing various issues. Once I switched from Dell control computers to HP, the errors went away.

[Ron Sloan]

Thanks for the replies. I`ll double check my grounding. I did recently add a vacuum hold down system to the machine, but no other issues have shown up. Runs fine otherwise.

Best regards,
Ron

[Donald Thomson]

Ron,

Make sure all your vacuum motors are properly grounded to the common ground point. I did something that most people wouldn't bother doing, I wrapped bare ground wire around my vacuum piping to make sure I could bleed off any static buildup. I know it sounds excessive but I learned, the hard way, the importance of good grounding systems.

With all the static vacuum systems (hold down and dust collection) can produce they can interfere with aircraft communications. LOL

[Ron Sloan]

Thanks Don,

Interesting idea about wrapping the vacuum piping! I will give that a try, if standard ground rules fail me!

Best regards,
Ron