I have a project that seems to be cursed. The first “oh no” happened a couple of hours into a roughing pass on a beautiful sunny day—the power flickered, causing a loss of XYZ coordinates and removing key parts of the wood. A piece that took up my entire spoil board could not be saved.
I always make sure to buy extra wood because mishaps are inevitable. For the second attempt, I managed to get through the roughing pass without issue. But after 5 hours of finishing, I made a critical mistake—I accidentally closed gSender while it was still running. I was certain I had ruined this attempt, but I was able to recover by carefully lowering the Z-axis just enough to correct the error.
I was feeling good, but it was short-lived as an afternoon thunderstorm swiftly rolled in, causing the power to flicker again and making another deep cut. As frustrating as it was, I was still able to save it by filling the damaged area with epoxy and starting again the next morning.
At 4:00 am the next morning, I’m in the shop because the weather forecast is giving me a 14-hour window with less than a 10% chance of rain. I get 55% through a finishing pass when I start hearing thunder. No, not this time. I return to XYZ zeros and safely shut it all down. I wrote down the line it stopped on and sat back to watch the rain while sipping coffee—and the damn power never flickered.
The next morning, with another good weather window, I prep for a good day. I carefully make sure the zeros are all correct. I use the “start from line” feature and click start. The router goes to the correct XY, but for some reason, I can’t figure out, the Z is way too low, and it gouges through the piece, breaking the bit.
Now I sit looking at 26 Board Feet, 13BF down with 13 to go. Yeah, I think “cursed” is appropriate.
@Swinly I’m sure that many here can sympathize, Lonnie. You likely have already thought of this, but since you seem to be in a location with frequent power blips, you may want to consider putting your controlling PC and the Long Mill on a UPS. At least then, when the power goes out, you have time to shut things down in a controlled manner. If the power event is just a blip, you need to nothing.
I thought about it briefly but wasn’t sure if it would work with the router too. I did a quick search here and saw a few thinking about it too but nothing where anyone put it into action.
Those are the essentials that need to keep functioning during an outage. These low-cost units are not at all powerful (350W for 5 minutes, give or take). but can power these low-power devices for hours. A full-blown CNC, on the other hand, will need a complete other beast.
Maybe you can change the power supply of your G-sender PC for a more robust one that has some good capacitors in it to keep it up for a small dip if the PC is the problem. I wouldn’t recommend using an UPS on the PC and longmill only. Dragging a bit around at 0 rpm might not give the results you crave, resulting in pushing swings again.
You might be able to rewire a low-cost UPS, keeping a relay active when it’s on the grid that gets released as soon as a dip flips the UPS into battery mode. With that relay, you could trigger a pause pulse while keeping your PC and mill running for a short duration. Maybe create a macro to raise the z-axis off the material to prevent a fire hassart and maybe even recording positions. I have no idea what can or cannot be done with macros, so I’m daydreaming here.
It’s not impossible, but it will take some proofs of concept and soldering time, or just a shipload of money to order a bloody tesla powerwall.
I would solder the bleep out of a couple of my upsses if I ever find myself pushing swings in a thunder storm.
Most ups systems are not equiped to run large inductive loads. The makita might only be 750 Watts, but it peaks way higher than that. You might break your UPS just connecting it to it, even in grid mode.
I have a diy solar system build at my mothers vegy garden. It’s primary function is to run a 600W pump to water plants. The inverter running it is a 1,5kW unit peaking at 2kW for a few secs. It works, but just. Over time, the old pump started stalling somewhat, pulling the inverter into overload. The pump run like sunshine on a normal outlet. I ended up replacing a perfecly good pump because I was a cheapskate buying that break-even inverter.
I’ve tried to run a hacksaw on that same inverter and while the saw was only 700W, it peaked way higher than the inverter could handle, resulting in the saw only humming a bit and a high pitched alarm buzzing from the garden shed.
That inverter was build to handle peaks, was overload protected so it lived . A UPS might not be so lucky.
i assume you would just need to keep the PC and the CNC driver board powered up. If i had that unreliable power I would do it that way and the moment the power went out, hit PAUSE (can this be automated) . Once the power is back up everything might still be in a good state. I wouldn’t continue to carve while on backup power. At work they had this problem. If the lights even blinked it would take 20 minutes to recover (not CNCs) They added backup for our servers but nothing else. It helps for blinks, but anything beyond a few seconds is still an issue.
Sorry, @Spamming_Eddie , I run my Shapeoko with a Makita router on a APC 1500 UPS all the time (and all my other electronics on their own UPS.) I’ve done the same with a APC 1000.
I’ve finished several pieces now when the power goes off completely. There’s always at least 30 minutes of UPS power available to finish a cut. The machine doesn’t even know the power went off.
So this is doable, which is good to hear. Since my laptop has internal power, keeping the CNC and router powered to survive a power blip or long enough to shut everything down is all I need to protect everything.
No need to sorry. I was pretty much assuming the whole thing together, based on halve baked related worst cases. You have covered a lot of testing ground others don’t have to wrestle through anymore.
Your link is dead so I cannot look at the device you are using and dive into the specs.
Jeesh, that kinda sucks! I’ve never run any files that were nearly as large, but can well understand your frustration.
Hope it works the next time around.
Marty from Kingston
Does the UPS need to be sine wave?
When you say 1000 or 1500, is that the output wattage? I’ve come across two APC1500s and the outputs are different—900 and 1500 output wattage. The 1000 is 600 output wattage.
Yes, sine wave. Everything else is not fit for purchase in this case.
You want the largest output wattage, because that will give the longest run time. That might come up on a long 3D carve.
We used to think about running only long enough to shut things down properly, but in this case we’re trying to continue a piece until it stops. That could be a short time or a long time. I went with the long time.
The last time I posted this link, Amazon threw a hissy fit!
