Power cuts

[rhfurniture]

Having just suffered a power cut, thought I'd better check out recovery strategy. Fortunately, this time, I was stood between files, so the position was safe. If I'm in the middle of a move, though, how accurately is the current position at time of cessation stored? Is it stored in the control box or on my computer attached to the shopbot program?
Natural caution would suggest re-zeroing but sometimes this is not easy.

Ralph.

[rhfurniture]

As an afterthought does anyone have a whole machine UPS? My own theory is that it is better that the machine stop altogether if the router head stops through power cut, so I don't have one on my computer or control box. Maybe if the position is stored in the control box it would be good to have one on that, but not the computer (and viky verky if it's stored on the computer).

R.

[Brady Watson]

When I read the title of this thread, I thought it was going to involve cutting at 10-12 IPS & full depth...LOL!

I know that several people run UPS systems on their bots, but I think the problem is that the router draws so much power that it will exhaust most affordable UPS' out there.

Here's a thought: What about a circuit that monitors output of a UPS and another circuit in your system? If the power goes out, the tool stops, triggers an input, and when that input it hit, it writes your XYZ coordinates as well as the line number that it stopped on?

There's got to be a few off the shelf components that can be used to accomplish this...I'd build one, but power has only gone out once in the past 6yrs I've been here...

-Brady

[scott_smith]

I haven’t thought it through completely but couldn’t Brady’s hypothetical output from the UPS just go to the e-stop input?
That way everything would just stop where it is and “R” to restart would send it on its way after the power is back on.

[patricktoomey]

I do something similar but even simpler. I have a relay box (relay wired to a small dc power supply) wired directly to the line feeding my spindle but after the circuit breaker. If power goes out on that line for any reason it triggers the e-stop line. The nice thing is that this handles multiple points of failure like overall power outage, overload in the spindle, somebody bumps the wrong breaker, etc. I have a UPS on the control computer so that it will keep running for quite awhile. In my area power goes out a couple of times a week in the summer so this has been a huge life saver for me.

[rhfurniture]

Brady, I'm quite happy in the slow lane, thank you.
I don't see this problem as being quite that complicated. When the power goes off (they are doing lots of building round here, and always cut through underground power cables - I get a serious interruption probably every six months) everything just grinds to a halt. I do sometimes get a "communication with serial port" error (I've noticed this is usually with RR command on a large file), and the machine stops wherever it is in a move. Recovery from that seems easy and accurate. I assume that if the computer goes out, it will do something similarly recoverable (must test it), so my inclination is to put a UPS on the control box to let it fully store the current position, but I was wanting to check my thinking, and whether it (ups) would make any difference anyway.
I can see that as a separate issue, to have a system for stopping all if the router dies would be a good idea, but I don't really know where to start with this on my Bosch router.

r.