Power Backup

[highpockets]

I've looked and I can't find this discussed anywhere so it must be so simple it's a non issue, but I just don't have the answer and could use some help.

I'm building my very first CNC Router. I'm from the computer world so as soon as you say computer I thing needs UPS battery power backup, not want it going down in a brown out or short power outage. OK that's fine a UPS is simple. Need to add the Mach3 controller box. OK that's simple just need a little bit bigger UPS. Now what happens when the computer and Mach3 controller keep running and the router spindle stops because of a power outage!!!! I'm thinking it's not pretty....

What is everyone doing to solve this problem

Thanks for the help.
John

[mike1966]

i dont use a power backup the power has gone out once in the last 3 years during a 12 hour carving when the power came back i just reran the same gcode and started from line 25000 so i didnt have to re cut the whole thing

[Adrian]

As Mike says it's pretty trivial to restart a job from the point where it started. You just need a way of accurately setting the XYZ to where it was at the beginning of the job.

It's not worth the expense when you factor in the power requirements for the spindle/router and a system good enough not to cause spikes and flip out the controller.

[scottp55]

John,
Looked up your machine and it looks like our power requirements are similar. Both our Desktops are in "country power" environments and we often experience "Blips" that will reset computers/oven clocks etc., and have frequent thunderstorms in the summer. We have UPS on both Desktops and have Everything into the UPS.
At the first rumble of thunder we simply unplug the UPS power cord/pause cut/turn spindle off and we're all set for an hour(have gone 1.5) before we have to shut down. We both have the HSD 1hp 110V spindle and if it's simply a "Blip" the machine never even notices it. If shop power is off longer than 30 seconds, we pause the cut/turn spindle off and wait. Had a power loss once before I "Dirtbagged" the UPS and happened to be sitting on the floor next to UPS and I glanced at the display and had 9 minutes estimate with the HSD cutting with an 1/8"bit.
Kirk took his Desktop on the road to Fairs and Shows 5 times this year and power was Really iffy and it saved his butt a few times.
No way with a bigger machine and a 220 spindle without spending $$$, but for our little machine and given our power surges, even if it was only a power filter I wouldn't be without it.
my 2 cents with a "tiny" machine.
scott

[CrowsWW]

I put a lot money in my CNC and I use the Liebert GXT3-1500RT120 for my shop computer & control panel. I also have an GXT3-3000RT208 for my VFD & Spindle. they work great. I also have an ACCUVAR TVSS - ACV120Y111RKE on my shop electrical Panel that takes any spikes out before they enter my shop. Not so great power where I am at. and this stuff is cheap insurance against power irregularities.

I also have an GXT3-1500RT120 for my PS3, Wii, TV, etc...

My wife has a commercial embroidery machine which she has a GXT3-500RT120 protecting it.

www.Liebert.com
you will have to purchase the GXT3's soon to be GXT4 from a electrical distributor or online from CDW, Newegg, tigerdirect, etc...

[scottp55]

UPS that I have here running the Desktop, 1hp spindle,monitor, computer, and 50W Halogen spot is a CyberPower 1500AVR. When I hear thunder I just Spacebar,unplug from wall, turn off spindle, wait... Then reverse that order and Resume. Longest T-storm was 1.5 hours. Tested while doing an air-cut back in the beginning with spindle at 14K and the estimate on the display was I think 28 minutes. Recommend as good as this or better so no lost comms.

From Shopbot thread back in November.
scott

[Adrian]

Glad I'm in the UK reading this! Even though I live in the middle of a forest with the power coming in on overhead wooden poles it's always clean and reliable. Even in major storms there's never any issue.

[highpockets]

To everyone, thanks for all the great replies.

Like I said before, I have to do some sort of power protection, I can't afford to take a chance.

Last night I came up with an idea that should work out, actually two ideas, one expensive, but complete coverage and the other less expensive, but should work out. I need to do some more research before I open my mouth and look really dumb(er).

Thanks again for helping a newbie and keep those suggestions coming.

[ChrisInEstes]

I have a UPS running my Mach3 computer & controller only. It takes care of the little power flickers I get once in a while. My spindle is a 5 HP 3 phase on a VFD, so I'm quite sure I can't afford a UPS system for it. So far, I've been really lucky in not having a power outage of more than a flicker while it was routing. A longer power outage would either break the bit or ruin the piece... or both, probably. It's a risk I take.

Chris

[highpockets]

I've come up with a very simple solution to the UPS Backup issue that also takes care of the spindle.

Use a UPS backup to take care of the computer and control box. To prevent the Mach3 from continuing to run if the power goes out and the spindle isn't running I'm going to use a 12V transformer AC/DC converter plugged into a surge protected only outlet on the UPS. The transformer will be hooked to the coil of a normally open relay. The normally open switch of the relay will be in series with the other estop switches. When power is lost the relay will de-energize releasing the switch to open causing a estop in Mach3. To prevent very short power glitches from causing an estop you put a capacitor on the relay coil to hold it up for a brief time after power is lost (the 12V transformer I used has a built in capacitor that holds the relay up for about a second and a half). If power comes back before the capacitor bleeds down then the relay doesn't de-energize. See the attached schematic.





Have a Great Day!
John