Question (WOODWEB Member) :
My last employer was all for letting the CNC machinery run by itself without anyone to watch or keep an eye on it. Every other shop I worked at stressed the point that I was to never leave the machine running unsupervised. Am I wrong? Is it safe to leave a CNC (that relies on a vacuum to hold the pieces in place) unsupervised? We built commercial cabinetry and used a Beamsaw, Nesting table and an older rail and stile type CNC.
From Contributor U:
This Knowledge Base article may be of help.
They had three machines doing this and were able to have the machines run about seven hours when they left for the day. They were using a paging system to notify an "on alert" operator if someone needed to come in and attend to anything. The machines were all Weeke's and the handling was a Homag system.
The operator that set up the machines oversaw the machines during the day but nobody was at a machine pushing buttons, all the operator did was set up which programs ran where and made sure the parts on the in-feed were staged correctly. I think the machines also used a probe to verify the part was there before the machining cycle started.
CNC routers and CNC point to point (pod and rail) panel processors are more easily adaptable to this type of operation. Unlike their metal counterparts, tooling life is very stable and significantly longer. The typical "type" of component being machined is relatively the same. That said, you still have to earn the right to improve and that requires dedication to systemic improvement.
Contributor G is correct, there are a lot of options on the metal side that facilitate this, however they are not as commonly used as thought. Example - many metal working job shops run very high mix/low volume. Order quantities of five or fewer are very common. If youíre placing a $10k titanium casting on a machine, there are not extra parts for setup or just in case. In most shops I have worked in, you hit the button and walk away from that, you might as well head on down to the employment commission! This is not to say there are not applications for unmanned, cellular or rapid set ups in this environment, rather it is very company, product, volume and application specific as to how you approach it.
They have robot fed horizontal milling with transfer from a loaded conveyor to the machine then from that machine to another to be reamed then washed and drained by the robot before placing on another conveyor. There is a pallettized milling machine that has 24 pallets, each with four sides and each side holding two parts. Itís manually loaded at the end of the day and runs most of the night lonesome. We let our router run a nest when we go to break or sit down for lunch. Just need to know not to run risky setups.