Unmanned CNC

Can you safely allow a CNC router to run unattended? August 22, 2013

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.

Forum Responses
(CNC Forum)
From Contributor U:
This Knowledge Base article may be of help.

Managing Long CNC Carving Operations

CNC Crash-and-Burn Stories

From contributor F:
I visited a furniture shop in Germany about 12 years ago and they used gravity feed conveyors that feed stacks of parts to the P2P machines. Each machine had a small load /unload arm that would blow off the finished part, move it to a stack, place a part from the in-feed, trigger a bar-code and then do the same thing in field number two.

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.

From Contributor S:
I'd love to see something like that in action. I have seen demos at the shows, but I have not seen 50 panels blast through labeled and ready to assemble.

From contributor G:
Machinists do this all the time, the machine calls them at home if something goes askew. This will be common place in woodworking before too long.

From contributor T:
Successful unattended operation depends on a lot of variables. Many of them have less to do with the actual mechanics and operations of the machinery at the machinery level, and more with the entire process and system as well as the specific application. Process stability (stable material, stable volume, predictability, customer specifications - all of these are considerations). It's the companies that focus on these that have fewer problems.

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.

From contributor L:
The company that provides some of our metal parts has quite a few machines that run all night with no operator present. All have video feeds to the internet so they can be checked on. The ones I have watched run all have auto sheet or part auto load/unload: CNC laser cutting sheet steel up to 1" thick, CNC punches making small parts including forming the edges. They have a robot fed milling machine on castings and palleting.

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.

From Contributor D:
Lights out machining has been around for many years. The main difference is that steel doesn't burn and most steel machining is done with coolant. I don't know high-end CNC routers well but the machine tools I'm used to have things like sensing if a tool was dull and replacing it. They also had constant surface speed. Both of these things avoid a dull tool running slowly creating heat and cutting a flammable material.