Just wondering if most cnc machines are dependable enough to leave running unattended? I'm guessing only if you've seen it make that particular part before without trouble?
If you are running production and want to stay in business you cannot afford to have someone hovering over the machine all the time and machines do run unattended for long cycles.
Some people get all worried but even if you are standing right there with your finger hovering over the E-stop button it is difficult to react fast enough to prevent problems.
Our experience is that with well written and proven programs bad things happen very rarely. Normally on lathes it is a parting tool failing or on lathes and mills a drill getting dull. In both casess it is possible to set the part count to a number that is well within the life of the tool and have the machine shut down or automatically switch to using a backup tool. Another preventative measure is to set the spindle load monitors at a level that is not reached during normal operation so that if a tool breaks the machine will alarm due to the increased load.
An open mind is a virtue...so long as all the common sense has not leaked out.
I leave mine go at it on its own once it starts cutting and it has cut the part before... especially now.
I just got a relay in the mail to automatically start and stop the mill. It takes a solid state DC relay to control the motor on my X3. At first I tried hooking it up to the motor directly and because of the slow startup required by the motor it would kick out the overload circuit as soon as it turned on. So I hooked it to the speed pot bypassing the P3 wire. That was the only wire that would work. I also got an AC solid state relay to control the flood. That was a simple hookup except the the plug outlet I hooked it to used 10 gauge wire and trying to reroute that heavy wire took a bit of effort. These relays came from China and took a good 10 days to get here but it was worth it. They are exceptional quality considering they were made in China. I used to have to pop in or make sure I was nearby before but now I can just go about other business and not even have to worry about coming back.
Every day. Ideally, I'll have 2 machines running, then I'll be off welding or doing CAD work, or even or rare occasion like today, doing lathe work. I love those 6 hour cycle time fixtured production jobs, they pay well. And as mentioned above, I can't afford to hover over the machine... Unless it's a VERY expensive "one off", then I don't go far.
I don't mind leaving the machine run unattended if it is on a long finishing program. But for drilling, tapping and general roughing, I stay in the room, because things could get really messed up if certain tools aren't there doing their job
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
I have been watching one or two passes of the program and then I feel pretty confident
about leaving it to run by itself. I have even let it run over night while I sleep.
My reason for converting to CNC at home seems to be different to most folks. All I want is repeatability for when I need to make a part after some time since the previous one. Speed for me is not important as it is for home use and my satisfaction but to be able (in my case) to load a drawing in and have the machine cut out the same after 6 months is. Mostly I cut foam patterns for castings and I prefer to use the LFC method as opposed to using a hard pattern since I am no good at woordwork anyway so a foam pattern I can bury in sand is far easier but it obviously needs a fresh pattern for each casting hence CNC. Apart from all that my workshop is not big enough to run more than one machine at a time.
My machine has always gotten into more trouble when I'm with it than when I'm not!
Most of my broken endmills have happened from a mistyped MDI command. Nothing quite like dropping a decimal point!
So far nothing serious, but I can say firsthand a 1/2" endmill snaps off clean when rapided full speed even into aluminum.
DOH! I hate when that happens.
Now with the ATC I can busy myself with other stuff even longer than before.
I still stay in the shop as my parts don't take any longer than 30 - 45 minutes.
The TV helps.
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